2010 BMW X6 40d E71
Discussion
Had a 335d for the last four years.
Been a great car, bought to be a big family car that was economical to commute in.
A lot changes in four years (i.e. an entire pandemic!) and it wasn't quite hitting the spot any more:
So what's the next best thing? You can guess by now.
Ideal requirements where sunroof, facelift (CIC iDrive), 8 speed gearbox and not too much slower than the 335d.
A couple came and went but were too far to go and see, and then this popped up fairly local...
2010 N57 40d in individual "pearl silver". Always wanted an individual BMW so that's something off the bucket list (even if it's not exactly the best individual colour ever!)
Decent spec with "dynamic package", sunroof, piano black interior and rear heated seats, but not "every option" like the ad claimed.
There is one small catch - it has two gears. Park, and neutral...
Seller claimed car lost drive, they scanned with a generic diagnostic that said the gear lever was faulty, but every garage they spoke to said it wasn't something they had the equipment to resolve.
I thought the gear lever itself was unlikely to be faulty - but it does control whether it's happy to engage drive (e.g. if the door is open, it'll pop it back into park) - so probably a different fault.
I scanned it for faults and the gearbox seemed ok (i.e. no major fault codes, pressure etc in range).
I'm not a big risk taker but I had a good feeling and, well, the good news is it was cheap...
Been a great car, bought to be a big family car that was economical to commute in.
A lot changes in four years (i.e. an entire pandemic!) and it wasn't quite hitting the spot any more:
- we bought an X5 which became primary family car, so no need for massive practicality
- WFH means no commuting - but most journeys now involve a toddler
- moved to somewhere a little more rural with worse roads, flooding etc
- I was bored
So what's the next best thing? You can guess by now.
Ideal requirements where sunroof, facelift (CIC iDrive), 8 speed gearbox and not too much slower than the 335d.
A couple came and went but were too far to go and see, and then this popped up fairly local...
2010 N57 40d in individual "pearl silver". Always wanted an individual BMW so that's something off the bucket list (even if it's not exactly the best individual colour ever!)
Decent spec with "dynamic package", sunroof, piano black interior and rear heated seats, but not "every option" like the ad claimed.
There is one small catch - it has two gears. Park, and neutral...
Seller claimed car lost drive, they scanned with a generic diagnostic that said the gear lever was faulty, but every garage they spoke to said it wasn't something they had the equipment to resolve.
I thought the gear lever itself was unlikely to be faulty - but it does control whether it's happy to engage drive (e.g. if the door is open, it'll pop it back into park) - so probably a different fault.
I scanned it for faults and the gearbox seemed ok (i.e. no major fault codes, pressure etc in range).
I'm not a big risk taker but I had a good feeling and, well, the good news is it was cheap...
So, I paid the money and left with... well nothing obviously. Later on my, delivery arrived.
Just fits in the garage, not fun doing it with manpower alone but it's in and on stands
First job was to remove the grille //M badge and the three (?!) wind deflectors
Next was a new battery - the car came with a spare battery and gear lever the seller bought, but didn't fit after finding out they needed to be coded to the car.
Luckily had the foresight to remove the boot floor etc before it went in the garage, as no access to the boot when tight up to the wall. So all work via the back seat.
Swapping out the 7 year old battery
Didn't fix the fault (unsurprisingly) but gave me a clean slate to clear everything down and rescan it - this car is also newer than I've worked on before so I've had to upgrade diagnostic software (INPA -> ISTA).
Lots of faults, including the gear lever - but interestingly at the very bottom was no communication to the transfer case.
Figured that'd be a good place to start - on earlier cars the controller is in the boot (which is still dismantled), but on later cars it's on the transfer case itself.
So, transfer case propped with a bit of wood
Crossmember removed
Controller removed
Checked all the pins for voltage and all looks good (but don't have the gear to check CAN).
While there the transfer case mount looked a bit worn.
Cut through the metal outer.
Lots of hammering and getting nowhere, eventually removed the centre by drilling through the rubber supports and then could "peel" the mount from the sides
Struggled to get the new one in all the way, refused to buy proper tools so made something out of wood. Wouldn't recommend, but it worked.
If there was voltage at the transfer case controller, I figured it might be dead so was going to buy another (they aren't *that* expensive) but then I remembered the plug came off very easily.
I looked back at the picture when I removed it and noticed the locking tang wasn't in place
Could it be, just not plugged in fully?
Put it back on, cleared the faults and we have communication, gave it a test and...
That's a gear!
After a little longer the traction control had a fit (presumably because it thinks all four wheels are sliding and the car isn't moving), and the transfer case has a warning for oil quality, so a little more work to do before I can drop it on the ground and test it for sure.
I've also put a cable tie through the transfer case plug to ensure the latch stays down to stop this happening again...
Next update could be positive, or very negative!
Until I know it drives (and that I actually like it - I've still not driven one!), I'm holding back doing anything else that needs doing.
Just fits in the garage, not fun doing it with manpower alone but it's in and on stands
First job was to remove the grille //M badge and the three (?!) wind deflectors
Next was a new battery - the car came with a spare battery and gear lever the seller bought, but didn't fit after finding out they needed to be coded to the car.
Luckily had the foresight to remove the boot floor etc before it went in the garage, as no access to the boot when tight up to the wall. So all work via the back seat.
Swapping out the 7 year old battery
Didn't fix the fault (unsurprisingly) but gave me a clean slate to clear everything down and rescan it - this car is also newer than I've worked on before so I've had to upgrade diagnostic software (INPA -> ISTA).
Lots of faults, including the gear lever - but interestingly at the very bottom was no communication to the transfer case.
Figured that'd be a good place to start - on earlier cars the controller is in the boot (which is still dismantled), but on later cars it's on the transfer case itself.
So, transfer case propped with a bit of wood
Crossmember removed
Controller removed
Checked all the pins for voltage and all looks good (but don't have the gear to check CAN).
While there the transfer case mount looked a bit worn.
Cut through the metal outer.
Lots of hammering and getting nowhere, eventually removed the centre by drilling through the rubber supports and then could "peel" the mount from the sides
Struggled to get the new one in all the way, refused to buy proper tools so made something out of wood. Wouldn't recommend, but it worked.
If there was voltage at the transfer case controller, I figured it might be dead so was going to buy another (they aren't *that* expensive) but then I remembered the plug came off very easily.
I looked back at the picture when I removed it and noticed the locking tang wasn't in place
Could it be, just not plugged in fully?
Put it back on, cleared the faults and we have communication, gave it a test and...
That's a gear!
After a little longer the traction control had a fit (presumably because it thinks all four wheels are sliding and the car isn't moving), and the transfer case has a warning for oil quality, so a little more work to do before I can drop it on the ground and test it for sure.
I've also put a cable tie through the transfer case plug to ensure the latch stays down to stop this happening again...
Next update could be positive, or very negative!
Until I know it drives (and that I actually like it - I've still not driven one!), I'm holding back doing anything else that needs doing.
Edited by Jakg on Tuesday 5th March 17:12
Jakg said:
After a little longer the traction control had a fit (presumably because it thinks all four wheels are sliding and the car isn't moving), and the transfer case has a warning for oil quality, so a little more work to do before I can drop it on the ground and test it for sure.
I've also put a cable tie through the transfer case plug to ensure the latch stays down to stop this happening again...
Next update could be positive, or very negative!
It's a negative unfortunately - all back together and on the floor and the "no communication" has come back.I've also put a cable tie through the transfer case plug to ensure the latch stays down to stop this happening again...
Next update could be positive, or very negative!
It definitely was communicating (temporarily!) so there's something else going on. Time to sleep on it!
Andy665 said:
That was a brave move to purchase - no reduction on asking would have covered a replacement gearbox
A second hand (not refurb) 8HP gearbox is ~£500. I doubt i'd be able to fit that myself, but worst case scenario (if it was just a gearbox) I'd probably still end up ahead. While I had the car jacked up, I thought it'd be a good idea to replace the brake fluid and all the bleed nipples
Unfortunately the brake fluid reservoir is under the scuttle, and they get fragile with age. Mines been glued together in the past, but the lid had become structural and fell apart when I took it off. Already on the list for replacement, just been moved up a bit. I also got distracted while bleeding and let a load of air in, so need to have another go.
Also noticed one of the "wings" on the front disc backplate was completely loose and touching the disk
Nothing holding it in at all, wouldn't have been good to come off at speed.
Already missing on the other side (and on the X5) so must be a common problem.
It definitely was communicating (temporarily!) so there's something else going on. Time to sleep on it!So I was a bit frustrated that I hadn't fixed it, but mostly I was confused - I was communicating with the transfer case, briefly - what happened?
The voltage with the engine running was a bit high:
I then checked the X5 and got a similar reading so was a bit stumped - but then checked my 335d (which had a new alternator regulator in the last year) and got a reading more like you'd expect (i.e. 14.x v).
I'd seen it suggested that in this scenario, the car shuts down systems and that disconnecting the alternator trigger wire can help - so I tried that, went for a gear and...
In hindsight, I'd jumped the gun a bit here - it wouldn't stay in reverse long enough to climb the (tiny) incline into the garage, so I had to get some help for the push of shame back into the garage.
But it does at least show there's an electrical fault I need to address, most likely the alternator regulator.
The alternators on the top of the engine, so access should be easy - but the tensioner is in the middle, so the fan has to come out to make space to get at it.
And if the fan comes off, some coolant hoses have to come off too, which meant it made sense to address some future jobs a little earlier.
Space made
The cars got the wrong coolant in, so it already needs draining and refilling. I haven't tested the thermostat, but all the diesel cars I've had have had broken thermostats, for £20 I put a new one in to avoid having to redrain later.
The drivers side of the engine has a thick coating of oil, tracked the source back to this boost hose. Common on M57 engines but not found much about the N57.
Some new seals from BMW.
Swapped the regulator on the alternator
Unfortunately no time to test yet though
So to feel like I'd actually fixed something
Battery vent tube had a broken elbow
Replaced
The next update probably won't be on the road (lets not jump the gun again!) - my current theory that the alternators put out too higher voltage and cooked some ECUs.
Unfortunately the brake fluid reservoir is under the scuttle, and they get fragile with age. Mines been glued together in the past, but the lid had become structural and fell apart when I took it off. Already on the list for replacement, just been moved up a bit. I also got distracted while bleeding and let a load of air in, so need to have another go.
Also noticed one of the "wings" on the front disc backplate was completely loose and touching the disk
Nothing holding it in at all, wouldn't have been good to come off at speed.
Already missing on the other side (and on the X5) so must be a common problem.
Jakg said:
Jakg said:
After a little longer the traction control had a fit (presumably because it thinks all four wheels are sliding and the car isn't moving), and the transfer case has a warning for oil quality, so a little more work to do before I can drop it on the ground and test it for sure.
I've also put a cable tie through the transfer case plug to ensure the latch stays down to stop this happening again...
Next update could be positive, or very negative!
It's a negative unfortunately - all back together and on the floor and the "no communication" has come back.I've also put a cable tie through the transfer case plug to ensure the latch stays down to stop this happening again...
Next update could be positive, or very negative!
It definitely was communicating (temporarily!) so there's something else going on. Time to sleep on it!
The voltage with the engine running was a bit high:
I then checked the X5 and got a similar reading so was a bit stumped - but then checked my 335d (which had a new alternator regulator in the last year) and got a reading more like you'd expect (i.e. 14.x v).
I'd seen it suggested that in this scenario, the car shuts down systems and that disconnecting the alternator trigger wire can help - so I tried that, went for a gear and...
In hindsight, I'd jumped the gun a bit here - it wouldn't stay in reverse long enough to climb the (tiny) incline into the garage, so I had to get some help for the push of shame back into the garage.
But it does at least show there's an electrical fault I need to address, most likely the alternator regulator.
The alternators on the top of the engine, so access should be easy - but the tensioner is in the middle, so the fan has to come out to make space to get at it.
And if the fan comes off, some coolant hoses have to come off too, which meant it made sense to address some future jobs a little earlier.
Space made
The cars got the wrong coolant in, so it already needs draining and refilling. I haven't tested the thermostat, but all the diesel cars I've had have had broken thermostats, for £20 I put a new one in to avoid having to redrain later.
The drivers side of the engine has a thick coating of oil, tracked the source back to this boost hose. Common on M57 engines but not found much about the N57.
Some new seals from BMW.
Swapped the regulator on the alternator
Unfortunately no time to test yet though
So to feel like I'd actually fixed something
Battery vent tube had a broken elbow
Replaced
The next update probably won't be on the road (lets not jump the gun again!) - my current theory that the alternators put out too higher voltage and cooked some ECUs.
Edited by Jakg on Thursday 14th March 08:12
(this is a boring update, it still doesn't drive)
The engine bay partition / scuttle panel are a common fault for disintegrating, mine had been previously repaired with glue but fell to bits when I was bleeding the brakes
Aftermarket ones are only £25.
When broken, water can drain off onto the engine instead, typically collecting around the injectors and causing issues. The aftermarket parts didn't have any weatherstripping unlike the genuine ones, something like butyl rubber is probably the right thing for the job but silicone sealant works fine and is what I had...
All back together and good as new
As part of this the pollen filter came out, too disgusting to go back in
There's an additional filter for the recirculated air on the inside as well, looked clean until I opened it up and you can see the fold at the bottom shows the filter is meant to be white!
While working on the car I also noticed both disc backplates were loose - some penny washers later and secured
Getting to the backplates required removing the caliper carriers, which were way overtightened. I was using a 3/8" adaptor for the socket and snapped two before eventually getting it undone with a 3/8" breaker bar and a trolley jack to get it started. Unfortunately found I had a 1/2" (so no adaptor required) when I went to buy one afterwards...
Jakg said:
The voltage with the engine running was a bit high:
With the new regulator, voltage is looking much betterThe engine bay partition / scuttle panel are a common fault for disintegrating, mine had been previously repaired with glue but fell to bits when I was bleeding the brakes
Aftermarket ones are only £25.
When broken, water can drain off onto the engine instead, typically collecting around the injectors and causing issues. The aftermarket parts didn't have any weatherstripping unlike the genuine ones, something like butyl rubber is probably the right thing for the job but silicone sealant works fine and is what I had...
All back together and good as new
As part of this the pollen filter came out, too disgusting to go back in
There's an additional filter for the recirculated air on the inside as well, looked clean until I opened it up and you can see the fold at the bottom shows the filter is meant to be white!
While working on the car I also noticed both disc backplates were loose - some penny washers later and secured
Getting to the backplates required removing the caliper carriers, which were way overtightened. I was using a 3/8" adaptor for the socket and snapped two before eventually getting it undone with a 3/8" breaker bar and a trolley jack to get it started. Unfortunately found I had a 1/2" (so no adaptor required) when I went to buy one afterwards...
(this is a boring update, it still doesn't drive - waiting on parts!)
Had some spare power steering fluid so thought I'd give it a change.
Sucked just under a litre out of the reservoir with a pipette - bottom left (green) is the colour of new stuff, bottom right (black) is the existing stuff.
It was disgusting and had suspended black bits in as well (probably adhered to the reservoir and loosened when agitated removing).
From my experience I doubt it'll make a difference to how the steering feels, but I certainly feel better about it.
The car has paddle shifters, but BMWs of this era have an odd arrangement where both paddles do the same thing - pull on *either* side upshifts and push downshifts - which is unlike any other paddle shifter arrangement I know of.
My 335d already came with this fixed, and the simplest solution is just to swap the wires on the left hand side paddle to reverse it. Very important to have paddles working intuitively, when you can't shift out of park after all.
This only applies to the earlier models, later models with the "newer" style paddles work differently IIRC
Airbag detached, trim unscrewed and popped free
And removed - note the X5/X6 has an extra pair of bolts holding the trim to the paddle shifter that means you have to remove the airbag, unlike the E9x where apparently you can wiggle the trim free without it (not that removing the airbag is hard)
Paddle shifter connector removed
"Hinged" flap on the connector opened
You need to swap top/bottom wires, depress the little locking tang on the pin to allow it to be removed
Had some spare power steering fluid so thought I'd give it a change.
Sucked just under a litre out of the reservoir with a pipette - bottom left (green) is the colour of new stuff, bottom right (black) is the existing stuff.
It was disgusting and had suspended black bits in as well (probably adhered to the reservoir and loosened when agitated removing).
From my experience I doubt it'll make a difference to how the steering feels, but I certainly feel better about it.
The car has paddle shifters, but BMWs of this era have an odd arrangement where both paddles do the same thing - pull on *either* side upshifts and push downshifts - which is unlike any other paddle shifter arrangement I know of.
My 335d already came with this fixed, and the simplest solution is just to swap the wires on the left hand side paddle to reverse it. Very important to have paddles working intuitively, when you can't shift out of park after all.
This only applies to the earlier models, later models with the "newer" style paddles work differently IIRC
Airbag detached, trim unscrewed and popped free
And removed - note the X5/X6 has an extra pair of bolts holding the trim to the paddle shifter that means you have to remove the airbag, unlike the E9x where apparently you can wiggle the trim free without it (not that removing the airbag is hard)
Paddle shifter connector removed
"Hinged" flap on the connector opened
You need to swap top/bottom wires, depress the little locking tang on the pin to allow it to be removed
(not a boring update, but it still doesn't drive)
The faults looking electrical, but I don't have the tools to diagnose further (but I probably will have to).
More specifically, it looks like there's a fault on the powertrain CANBUS, but the ISTA test plan basically says "try driving the car, it might go away on it's own".
I checked the gearbox oil level (low fluid would cause these issues) and while the level was fine, the gearbox oil wasn't.
It's on the left, new (admittedly ZF lifeguard 6) fluid is on the right... it's really, really dark. This seemed like a more sensible place to start.
ZF oil service kit ordered
There's very little clearance between the transfer case crossmember and the gearbox sump, making some bolts very awkward. I made a tool (just a cut down torx bit) to do this on the X5 but it's gone missing, so made another
Sump removed
Unfortunately one of the bolts snapped in the gearbox - the threads are open on the other side so I reckon water's got in from the top and corroded it
Drilled it out and the thread was savable which was very, very lucky
Dropped the mechatronics unit
The gearbox oil is very expensive (£20 a litre) so it makes sense to think about anything else at the same time.
On the ZF6, the seals wear and cause issues so I thought I'd see if there was a ZF8 equivalent. Not as much info online about this, but found a seal kit that replaces the seals between the mechatronic unit and gearbox. Not pictured is the clutch B seal that took forever to arrive separately.
I also dropped the transfer case bracket as the mechatronic sleeve would've been very difficult to remove with it in place. So homemade tool was for nothing.
The seal kit came with a new plastic "pressure pipe", but my car already had a metal one. So I swapped just the o-rings over. None of the old stuff looked worn, but was noticeably tighter when re-installing.
Clutch B seal was noticeably more proud than before showing the wear over the years
When I was trying to get a seal kit, the seller recommended that my issue was likely to be the solenoids.
My understanding is that the gearbox has a pressurised oil supply, but the solenoids control where the oil flows - and the oil pressure is what actually shifts mechanically (hydraulically?). The gearbox defaults to park with a big spring, whose resistance must always be counteracted.
The solenoids can be tested with a multimeter, but all tested ok - which makes sense, as if not it's likely I would've had a specific fault code.
Still, the solenoids have their own seals and filters etc, so I splashed out on a new solenoid kit, which includes the parking release valve. Genuine ZF parts, and not very cheap at £260.
These parts took *ages* to arrive, and the whole time the car was parked with the sump and mechatronic unit on the bench. It was slowly dripping out transmission oil. When DIY servicing, the torque converter holds some amount of oil you can't drain, and the kits are sized appropriately.
I suspected it'd need a bigger fill than usual, so did the usual cold fill and then started the car to get the oil pumped around and turned it off again. Straight away a lot more could go in.
The next step is to get the gearbox up to temp while stationary and then the final fill - after waiting ages for the gearbox to warm up, just as I got to put more oil in, it kept taking it and taking it until I had no more oil left!
Another bottle of oil later, repeating the whole filling process, and in total, 7.5L of new oil has gone in.
I did the filling process via ISTA, and as new solenoids the adaptations were reset, too.
It seemed ok when up in the air, but back on the floor and the problems still there unfortunately. Frustrating (and expensive, with over £500 of bits...), but it's good preventative maintenance.
I also got frustrated with my tiny workbench, so while waiting for various parts I made one.
In hindsight, not a good idea when you have an immobile, oversized car taking up the space - you need space to work, space for the new bench, space for the old stuff and I spent a lot of time falling over myself.
Not finished, but together enough I can carry on with the car for now.
Speaking of which, the car is now *covered* in sawdust. So that's another job to deal with.
The faults looking electrical, but I don't have the tools to diagnose further (but I probably will have to).
More specifically, it looks like there's a fault on the powertrain CANBUS, but the ISTA test plan basically says "try driving the car, it might go away on it's own".
I checked the gearbox oil level (low fluid would cause these issues) and while the level was fine, the gearbox oil wasn't.
It's on the left, new (admittedly ZF lifeguard 6) fluid is on the right... it's really, really dark. This seemed like a more sensible place to start.
ZF oil service kit ordered
There's very little clearance between the transfer case crossmember and the gearbox sump, making some bolts very awkward. I made a tool (just a cut down torx bit) to do this on the X5 but it's gone missing, so made another
Sump removed
Unfortunately one of the bolts snapped in the gearbox - the threads are open on the other side so I reckon water's got in from the top and corroded it
Drilled it out and the thread was savable which was very, very lucky
Dropped the mechatronics unit
The gearbox oil is very expensive (£20 a litre) so it makes sense to think about anything else at the same time.
On the ZF6, the seals wear and cause issues so I thought I'd see if there was a ZF8 equivalent. Not as much info online about this, but found a seal kit that replaces the seals between the mechatronic unit and gearbox. Not pictured is the clutch B seal that took forever to arrive separately.
I also dropped the transfer case bracket as the mechatronic sleeve would've been very difficult to remove with it in place. So homemade tool was for nothing.
The seal kit came with a new plastic "pressure pipe", but my car already had a metal one. So I swapped just the o-rings over. None of the old stuff looked worn, but was noticeably tighter when re-installing.
Clutch B seal was noticeably more proud than before showing the wear over the years
When I was trying to get a seal kit, the seller recommended that my issue was likely to be the solenoids.
My understanding is that the gearbox has a pressurised oil supply, but the solenoids control where the oil flows - and the oil pressure is what actually shifts mechanically (hydraulically?). The gearbox defaults to park with a big spring, whose resistance must always be counteracted.
The solenoids can be tested with a multimeter, but all tested ok - which makes sense, as if not it's likely I would've had a specific fault code.
Still, the solenoids have their own seals and filters etc, so I splashed out on a new solenoid kit, which includes the parking release valve. Genuine ZF parts, and not very cheap at £260.
These parts took *ages* to arrive, and the whole time the car was parked with the sump and mechatronic unit on the bench. It was slowly dripping out transmission oil. When DIY servicing, the torque converter holds some amount of oil you can't drain, and the kits are sized appropriately.
I suspected it'd need a bigger fill than usual, so did the usual cold fill and then started the car to get the oil pumped around and turned it off again. Straight away a lot more could go in.
The next step is to get the gearbox up to temp while stationary and then the final fill - after waiting ages for the gearbox to warm up, just as I got to put more oil in, it kept taking it and taking it until I had no more oil left!
Another bottle of oil later, repeating the whole filling process, and in total, 7.5L of new oil has gone in.
I did the filling process via ISTA, and as new solenoids the adaptations were reset, too.
It seemed ok when up in the air, but back on the floor and the problems still there unfortunately. Frustrating (and expensive, with over £500 of bits...), but it's good preventative maintenance.
I also got frustrated with my tiny workbench, so while waiting for various parts I made one.
In hindsight, not a good idea when you have an immobile, oversized car taking up the space - you need space to work, space for the new bench, space for the old stuff and I spent a lot of time falling over myself.
Not finished, but together enough I can carry on with the car for now.
Speaking of which, the car is now *covered* in sawdust. So that's another job to deal with.
Edited by Jakg on Thursday 25th April 14:27
Edited by Jakg on Thursday 25th April 14:29
Edited by Jakg on Thursday 25th April 14:31
Jakg said:
Checked all the pins for voltage and all looks good (but don't have the gear to check CAN).
Jakg said:
The faults looking electrical, but I don't have the tools to diagnose further (but I probably will have to).
The only faults I had were communication faults
It'd had errors between different modules and I'd already checked the obvious joints and connectors, but couldn't see anything - but it was consistently the powertrain CAN network (PT-CAN) with issues.
You can view signals on a CAN network with an oscilloscope, so I bought and one and some super handy backfeeding probes so I could watch the traffic at a module while it was still plugged in.
Engine ECU (DDE)
Specifically (and I'm going to butcher this explanation), the pair of wires send a 1 or 0 with the signals across both CAN lines - CAN-high and CAN-low refers to their "off" voltage, and they drop (or increase) respectively to indicate "on"
This means both lines signals can be checked against each other to validate they are working correctly, including if they are shorted with each other / ground / positive.
You can watch this pattern on an oscilloscope. I was *expecting* intermittent bad signals at a module due to a wiring fault
Unfortunately, the signals were all fine - I checked a couple of places and you can see the pattern clearly.
The last place I checked was the handbrake (it's electric) - it's on the PT-CAN, and there's always been an error about it and it's not worked.
However, they are known to fail and while the seller said it'd been replaced, he also told the recovery driver not to use it so I figured I'd get round to that later.
The connector was broken and held together with a cable tie.
Still, CAN tested fine at the plug, too.
So, at this point I was feeling a bit dejected... every step I'd taken had found problems, but nothing was actually fixed. I resigned myself to a new gearbox.
Edited by Jakg on Thursday 2nd May 10:03
Edited by Jakg on Thursday 2nd May 10:08
Jakg said:
So, at this point I was feeling a bit dejected... every step I'd taken had found problems, but nothing was actually fixed. I resigned myself to a new gearbox.
I really, really didn't want to replace the gearbox (for a start - how on earth was I going to get the car high enough in the garage!).So I tried a couple more steps:
- Reset the DSC module (based on a suggestion)
- Reset the steering angle sensor - this was required after resetting the DSC module, and although I'd already done this, the process seemed... different this time?
- Cleared and rescanned for faults
Stayed in gear, with my foot on the brakes in the air.
This is weird...
Put it back on the ground... and rolled out of the garage without issue.
Quick hose to get rid of all the saw dust
And here it is, not at home in the garage!!!!
So what was wrong?
Anti-climatically, I don't know!
Either:
- The communication fault was a red herring - ISTA does suggest that kind of fault *may* go away when the car is driven, but I obviously wasn't able to test that - so fixated on the fault code
- I failed to calibrate the steering angle sensor properly, after the battery/alternator was replaced
- The plug on the handbrake module wasn't connected properly, and that caused the whole car to enter some kind of limp mode
Now it's fixed and I'm keeping it, I can do all the non-essential jobs. Still no idea if I like it yet, though!
Watchthis said:
Where did you purchase the zf8 solenoids and seals from?
Solenoids - https://www.autodoc.co.uk/zf-getriebe/15816662 - for reference, I paid £260 - the prices change daily so if it's expensive today, try again tomorrowSeal kit - https://www.sussexautos.com/products/8hp45-8hp70-m...
Clutch B seal - https://www.ic24.uk/products/f826a2-automatic-gear... - took about 2 weeks to arrive from Poland, but can't argue less than a fiver delivered
Jakg said:
The last place I checked was the handbrake (it's electric) - it's on the PT-CAN, and there's always been an error about it and it's not worked.
However, they are known to fail and while the seller said it'd been replaced, he also told the recovery driver not to use it so I figured I'd get round to that later.
The connector was broken and held together with a cable tie.
Luckily available separately (...for £16...), good as new.However, they are known to fail and while the seller said it'd been replaced, he also told the recovery driver not to use it so I figured I'd get round to that later.
The connector was broken and held together with a cable tie.
Clocked up some miles now and, touch wood, no gearbox issues.
First impressions are:
I think for most people (including myself) the X5 is probably a better (and cheaper) option, which I already knew!
I'm also still £2k up on the cheapest X6 40d for sale right now (ignoring tools and labour), which is nice.
Another not-in-the-garage shot
I now have three cars with identical keys, which is absolutely infuriating
First impressions are:
- despite being an X5 underneath, it feel more like a car than an SUV to drive. I think it's the much smaller windscreen that tricks your brain. I'm not sure this is actually a good thing!
- the gearbox (8HP) is much better than the older 6HP in my 335d/X5
- the steering is unpleasantly light, with no feel. Maybe I'll adjust?
- ride over rough surfaces so much better than my 335d
- black seats, black leather, black headlining, black trim with a small sunroof (no pan roof on X6!) means it feels a little dark inside
- wing mirror cameras make it very easy to park
I think for most people (including myself) the X5 is probably a better (and cheaper) option, which I already knew!
I'm also still £2k up on the cheapest X6 40d for sale right now (ignoring tools and labour), which is nice.
Another not-in-the-garage shot
I now have three cars with identical keys, which is absolutely infuriating
Edited by Jakg on Wednesday 8th May 11:45
Fas1975 said:
Love it. Had an E71 40d myself for 3 years. Chopped it in for an X6M F86 and regretted it almost immediately.
Interested to know what you didn't like about the M - I was originally after an E71 X6M but there was a big variation in prices.Fas1975 said:
I keep scouring the ads for a petrol E71 with the right spec.
Petrol makes way more sense for my usage profile, but there were barely any for sale and at stupid prices.d_a_n1979 said:
You could always 're-case' the key so it stands out more: https://www.ebay.co.uk/itm/204318687658?fits=Car+M...
Not sure that'll work, it's not keyless and there's a tight slot for the key to sit in. I did think about a cover for the key but decided against it for that reason.There's some animal stickers in the post right now...
X6's come with a 21mm rear anti-roll bar.
Same is used on the E70 X5, but the sport-suspension models get a 23mm one (as does the F16 X6 as well).
Access is fairly easy, just four bolts. Normally would swap the bushes and drop-links etc but my wallet still stings a bit and the ones on the bar I bought were better than what I already had fitted.
Working outside because the garage has a different immobile car for a change
Access is good but everything is crusty
Some penetrant later and the links came off without issue, was amazed
Slightly awkward getting the bar out - mostly because it's a metre long and the cars not that high off the ground, struggled to get the stands stable on gravel.
You can visually see the bottom one is a little thicker.
Same is used on the E70 X5, but the sport-suspension models get a 23mm one (as does the F16 X6 as well).
Access is fairly easy, just four bolts. Normally would swap the bushes and drop-links etc but my wallet still stings a bit and the ones on the bar I bought were better than what I already had fitted.
Working outside because the garage has a different immobile car for a change
Access is good but everything is crusty
Some penetrant later and the links came off without issue, was amazed
Slightly awkward getting the bar out - mostly because it's a metre long and the cars not that high off the ground, struggled to get the stands stable on gravel.
You can visually see the bottom one is a little thicker.
Jakg said:
The drivers side of the engine has a thick coating of oil, tracked the source back to this boost hose. Common on M57 engines but not found much about the N57.
Unfortunately this was not the main problem - after swapping, even before I got it back on the road, there was visible oil on the bottom of the engine.The tell tale is oil leaks off and onto the exhaust flexi, which burns off when hot causing smoke (and obviously an unpleasant smell).
The rocker cover gasket is a common problem on the N57, but also so is the rocker cover itself - it's plastic sections, glued together from the factory which can crack or warp.
I watched some videos on replacement and read TIS but it seemed like a lot of work, inlet manifold and scuttle trims needed removing etc. When I started I got even more confused - the TIS instructions didn't map to the car, and it seems like the ancillaries on N57 cars are very different, changing what needs to be removed etc so I just ended up guessing most of it.
Airbox, inlet piping, injectors, pipework and fuel rail removed
The injectors came out very easily (I got the engine hot in advance), which was good as they are known for being problematic.
The injectors were looking a bit of a state however
There's a receipt a couple of years ago for a new rocker gasket and injector seals, someone's definitely been in here before.
I've removed injectors on an M47 before and just put them back in many times without issue, but this time I thought I'd do it "properly" - injector bores cleaned, seats recut etc
Cleaned the injectors up and gave them an ultrasonic bath as well, they still aren't pretty but much cleaner. New copper washers and leak off o-rings.
When I removed the injector clamp bolts (which go through the valve cover) they were all covered in oil, which isn't right
Quite a bit of fighting later and the cover was off
There's a wiring loom that circles around 3/4 of the engine, and then all the pressure converters with it's vacuum lines on the other side. So you need to disconnect a lot of stuff to get slack to free it up. But all done without removing inlet or scuttle panel.
Old vs new cover
It's an aftermarket part and although advertised for my car, the N57 had two different variations of cover - the later one is a slightly different design, which is what this actually is, and I had the earlier one. Different shape gasket (not an issue now obviously) and has a separate part to mount the engine cover is, which wasn't included annoyingly so I've ordered one separately.
Closer inspection and the old rocker cover looked ok, but the gasket (which is 6 years old) looks like it's melted
Cleaned up the mating faces and put it all back together - I was a bit worried with all the cleaning I'd contaminated the oil with fluids etc so I gave it a change as well, and fitted a magnetic sump plug.
Because the fuel system was drained down, I bled it on ISTA before starting - it would've started eventually, but this apparently makes things easier on the high-pressure fuel pump.
All back together and... nothings exploded. Which is good going, as this was one of the more complex jobs I've tackled. Whether it's fixed the leak, we'll see!
Edited by Jakg on Saturday 18th May 00:24
The X6 came with CIC iDrive, USB & Bluetooth, but in early CIC fashion you can't stream music over bluetooth and USB is for USB drives, not phones.
I tried to fit a USB 3.5mm Bluetooth adapter as a temporary measure, but something was broken internally in the 3.5mm socket so I replaced that.
I also fitted a USB C power supply for faster charging. Not the neatest install, but fairly hidden in the armrest.
I tried to fit a USB 3.5mm Bluetooth adapter as a temporary measure, but something was broken internally in the 3.5mm socket so I replaced that.
I also fitted a USB C power supply for faster charging. Not the neatest install, but fairly hidden in the armrest.
Jakg said:
The X6 came with CIC iDrive, USB & Bluetooth, but in early CIC fashion you can't stream music over bluetooth and USB is for USB drives, not phones.
The solution to these problems is a Combox - BMW speak for an optional multimedia interface found on slightly later CIC iDrive installations.I have one in my 335d and it works well, but it came already retrofitted. To get one installed is >£400 so I thought this would just sit on the back burner for a bit.
I typed the part number into eBay expecting to have to wait and instead there were loads, and £50 later I had one to work out how to fit.
The car currently has the TCU & MULF modules, which the Combox replaces.
The TCU is on the wheel arch in the boot, and the combox goes here.
The MULF module is under the rear seats on an X6 - on an X5 it's next to the TCU, which would've been much easier.
Removed the seats and pulled all the wiring back.
The combox uses a different connector, but requires the connections from both the TCU & MULF.
Luckily I already had a TCU -> Combox adaptor spare
I just needed to connect the MULF connections into the combox plug as well.
Unfortunately because the MULF was further away, the connections weren't long enough to get back to the combox, so they had to be extended. I tried soldersticks for the first time over crimps, mostly so that when terminated it wouldn't be too bulky so could rewrap the loom.
On the combox end I bought the proper MQS terminals so that it *should* just clip in like factory... unfortunately, it didn't.
In hindsight, I should've got the genuine BMW connections with a loom on the end and used those as the extensions, and wired it up without the adaptor as well into a new single connector.
Combox fitted with some slight modifications to the aerial connection.
All together and looks fairly neat thanks to lots of loom tape...
Coding was fairly straightforward:
- Write the VIN to the combox (note - it's the VIN the car is coded with, not the actual VIN - theres no check digit on the one on the car!)
- Update the VO codes to remove the TCU+MULF stuff and add the combox stuff, write back to the car
- Default-code some of the modules so they reconfigure themselves around the new VO
- Code out the TCU SOS warning as I couldn't get it to go away otherwise
After all that, USB phone connectivity, with album art
I was getting poor audio quality (popping, crackling etc) and it was suggested it might be a MOST issue - the TCU, MULF, amp etc all sit on the MOST fibre optic loop, so if you remove one (e.g. like I have with MULF gone) you have to bridge the cable to keep the loop connected.
I tried a different bypass loop but that didn't work at all, I found that the MOST loops seem to all go via a junction box which happens to be next to the combox etc - I could remove the whole redundant MOST leg that went to the MULF and move the connections over like it was never there, which is much neater.
Removed MOST cabling vs bypass
Back together and works fine now, and the whole retrofit has been less than £60, so I'm happy, plus I learnt quite a bit.
Finally, updated the 14 year outdated maps
Edited by Jakg on Wednesday 29th May 22:29
The wing mirrors are auto-dimming, but one of the seals has failed causing one of the mirrors to go yellow.
Tricky finding dimming glass that isn't £££ but eventually got some from AliExpress.
Now it's on the road proper, parking in the garage is a real faff - the garage is only about 30mm (not cm!) longer than the car, so while possible, you need to park, get out, check, creep forward several times etc.
I made a little stopped ramp out of wood at the exact right position - you just drive in (slowly!) and the car will stop in the perfect stop, it won't creep up the ramp. Makes parking very easy and only slightly nerve-racking.
It's braced off the wall because I didn't want to attach it to the floor:
Tricky finding dimming glass that isn't £££ but eventually got some from AliExpress.
Now it's on the road proper, parking in the garage is a real faff - the garage is only about 30mm (not cm!) longer than the car, so while possible, you need to park, get out, check, creep forward several times etc.
I made a little stopped ramp out of wood at the exact right position - you just drive in (slowly!) and the car will stop in the perfect stop, it won't creep up the ramp. Makes parking very easy and only slightly nerve-racking.
It's braced off the wall because I didn't want to attach it to the floor:
- it's easily moveable - you just pick it up if you want a different car
- I was worried any holes in the floor would fill with water and freezing might crack the slab
Cleaned it - still not really a looker
Got frustrated that everything in the boot goes everywhere in the corners.
There's no hooks for a cargo net, and the boot liner is super slippy
Bit annoying as the E70 X5 has the hooks as standard, and my 335d has the extended storage pack so loads of hooks etc.
When new, you could (and should!) have spent ~£200 on the extended storage pack - which gives a storage net, bag hooks and storage rails.
The rails replace the trims either side of the boot floor, with hooks that can be moved along the rails to give flexible storage etc. As they are X6-specific and an optional extra, they aren't plentiful second hand - these came from a European X6M so at least I get bragging points for //M parts.
Quite a lot of the boot trim overlaps, so the floor, side trims, part of the rear trim and the C pillar trims all have to come off. The car has the threads in the chassis from factory.
The unit came without bolts, but I couldn't stomach 8 bolts at £3.50 each from BMW. Instead spent £3.50 on some cap heads on eBay (12.9 grade no less!) and sprayed the washers black.
Need a bigger cargo net but you can see it's much more practical all back together
Extended storage also gave you some little fold down hooks in the side trims - luckily these are used on loads of other cars (e.g. E91, E61 etc) but still tricky to find a set second hand.
The trims are premarked, so you just cut them out - I used a junior hacksaw blade, as the plastic is too recessed to use a dremel properly, but hard enough you need a proper tool.
WIP:
Pops in
Fitted
And opened
There's one on each side.
There's some other extended storage parts still missing but I'm not so fussed about those, and they are all X6 specific so I'll probably never find them separately.
Got frustrated that everything in the boot goes everywhere in the corners.
There's no hooks for a cargo net, and the boot liner is super slippy
Bit annoying as the E70 X5 has the hooks as standard, and my 335d has the extended storage pack so loads of hooks etc.
When new, you could (and should!) have spent ~£200 on the extended storage pack - which gives a storage net, bag hooks and storage rails.
The rails replace the trims either side of the boot floor, with hooks that can be moved along the rails to give flexible storage etc. As they are X6-specific and an optional extra, they aren't plentiful second hand - these came from a European X6M so at least I get bragging points for //M parts.
Quite a lot of the boot trim overlaps, so the floor, side trims, part of the rear trim and the C pillar trims all have to come off. The car has the threads in the chassis from factory.
The unit came without bolts, but I couldn't stomach 8 bolts at £3.50 each from BMW. Instead spent £3.50 on some cap heads on eBay (12.9 grade no less!) and sprayed the washers black.
Need a bigger cargo net but you can see it's much more practical all back together
Extended storage also gave you some little fold down hooks in the side trims - luckily these are used on loads of other cars (e.g. E91, E61 etc) but still tricky to find a set second hand.
The trims are premarked, so you just cut them out - I used a junior hacksaw blade, as the plastic is too recessed to use a dremel properly, but hard enough you need a proper tool.
WIP:
Pops in
Fitted
And opened
There's one on each side.
There's some other extended storage parts still missing but I'm not so fussed about those, and they are all X6 specific so I'll probably never find them separately.
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