2008 BMW 335d E91

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Jakg

Original Poster:

3,463 posts

168 months

Friday 7th February 2020
quotequote all
A small announcement from the wife means I need something larger than my 3 door Megane.

Like most PHers I've been thinking about the next car as soon as I bought the last one - an E91 seemed the obvious choice but while I wanted a 335d, they seemed to hold their value quite well and there weren't that many on the market so it looked I'd have to settle for a 325d/330d.

The time to look was over and I needed to buy something so I had a look on Facebook and found something that caught my eye - not exactly what I was after, but it was the cheapest 335d that wasn't a write off / >200k miles / in Bradford and more interestingly had £8ks worth of extras, so i thought I'd have a look.

Drove down to have a look and I was impressed. The seller was nice bloke, the car was in a good condition, couldn't find anything wrong with it. Agreed a price and returned the next weekend to collect - only dampened slightly by buying a train ticket for the wrong day (!) and having to buy the correct ticket mid journey.


Let's get the bad bits out of the way first - it's a pre-LCI, it's done 135k, it's grey, it's an SE.

Good bits - panoramic sunroof, adaptive bi-xenon headlights (inc high beam assist), iDrive CIC retrofit. £8k worth of options (even down to stupid stuff like puddle lights that project "BMW" on the floor).



It drives much better than a car of this mileage has any right to - doesn't feel loose or baggy at all.

Up to 8/10ths it drives very well but when you push it the weight suddenly becomes apparent

Despite the hate online, the gearbox seems alright to me - certainly not slow and clunky or anything. Manual mode is clearly a gimmick, though.

Due to the refinement and gearbox, it doesn't feel that quick but it just hides it well.

Brakes are surprisingly decent too - I expected it to be a bit weak with single piston calipers but the discs are 348mm and only just fit under the 17" wheels.


In terms of tech, it's clearly a generation newer than I'm used to - there's even a button that cools the cupholders.

The previous owner retrofitted the iDrive CIC system - which is the next generation newer iDrive system than came as standard (CCC).

I'm used to dealing with car audio and expected to chuck the 10 year old system in the bin and fit a decent headunit, but having used it I'm really impressed - navigation (with up to date maps and traffic), bluetooth, USB, parking sensors etc all bundled into a decent interface built into the car. I'm not sure I could justify the ££££ he spent on it, but I'm glad he did!

The boot is a lot smaller than I perhaps expected - it's midway between my Megane and my wifes Kia Cee'd. And because of the iDrive system, and a lack of spare wheel, there's no space under the boot floor either. But really I wanted a 5 door with a slightly larger boot, not a 5-series or something, so I hope it'll be ok.

Most importantly - the wife approves!

It's parked up until I've sold my current car so forgive the poor pictures...






Jakg

Original Poster:

3,463 posts

168 months

Friday 10th April 2020
quotequote all
Sold my Megane so it's back on the road.

Went for a swim (remember when we could leave the house to do that?!). Parked up next to a Fiesta, only to realise it's taller than an E91! I never realised what a "compact" estate it was.



First mod, phone holder, charger and dashcam hardwired. Dashcam isn't fitted yet as the windscreen needs replacing.



For a big car, up front there's little space, so in goes a sunglasses holder


Jakg

Original Poster:

3,463 posts

168 months

Friday 10th April 2020
quotequote all
Next, some more exciting (or at least, in-depth) stuff.

Scanned with INPA, all 6 glow plugs were showing as faulty



Seemed unlikely, Google suggested instead it was probably the glow plug controller.

I'd seen no ill-effects but i'd seen references that a glow plug fault could cause the DPF not to regen.

Officially you need to remove the inlet manifold to get to it, but as is always the way I found a video on YouTube where someone does it in situ in 5 minutes, so I thought I'd have a go.

Engine cover and scuttle off, and after more than 5 minutes, I'd found where it was - you can just see one of the nuts securing it, which gives you a sense of how buried it is!



(as usual, the slightly manky food isn't for me - it's for my dog!)

Removing the bolts took a rather absurd combination of extensions and wobble joints



But after a lot of manipulation, out it came



Edited by Jakg on Monday 7th August 21:53

Jakg

Original Poster:

3,463 posts

168 months

Friday 10th April 2020
quotequote all
Why did the glow plug controller break?

If the car doesn't warm up fully, the glow plugs never turn off, the controller burns out.

Now when I bought the car, I knew the thermostats were a common problem on the 335d, but when I was talking to the seller they said they'd recently had the EGR thermostat replaced. The car has no temperature gauge, and I forgot to check.

After a 45-min drive, the max temperature it got to was 59° C.



The EGR thermostat looked new so I figured it must be the main thermostat.

With the engine cover, airbox, pipework & EGR cooler off, access wasn't too bad. You can just about see where it goes from the coolant in the middle.



New thermostat and some new bolts



Put it all back together and used the opportunity to replace the coolant.

I used the correct G48 coolant. I didn't realise that there was a special kind of coolant for BMWs - I've used the wrong stuff on my Z4.



Put it all back together and unfortunately, it leaked... from the EGR thermostat.

When disassembling I'd removed it and noticed that one of the threads had ripped out and been replaced by a nut, and there was a lot of black sealant all over it. And the sealing O-Ring was destroyed.



In addition, the mating face on the EGR cooler was bent.



No wonder there was sealant all over it...

A bolt was missing too (which I'm still waiting for) but overall not impressed with the quality of that job!

I bought a second hand EGR cooler (only £17 - this one was off a 118D), which was perfectly flat.



I also managed to break the EGR thermostat by splitting the two halves and couldn’t put it back together, so thought buying a new one would give me piece of mind.

The cars new EGR thermostat was unbranded, but the EGR cooler came with a BMW genuine one.

I'd bought a new BEHR one and for the first time I found one of the mythical "OE part with the part number ground off" parts!



Put it all back together and it runs much warmer now



It takes a long while to warm up on the drive, but I haven't got it hot enough to open the thermostat yet to bleed the system properly. It would be much easier if I could just drive it - but that's obviously difficult at the moment.

Edited by Jakg on Friday 10th April 02:40

Jakg

Original Poster:

3,463 posts

168 months

Friday 10th April 2020
quotequote all
With it up in the air I had a general poke around and noticed common problem - a very oily looking intercooler hose



The seals are a weak point and ridiculously priced from BMW (~£30 and then ~£200 for the hose!) so I just replaced the whole hose with an MTC unit.



Slightly fiddly to fit, especially as I had to remove a small tab from the intercooler (which was easy - but there were no instructions and it's a well made custom part so I thought it was a straight swap)


Jakg

Original Poster:

3,463 posts

168 months

Friday 10th April 2020
quotequote all
Before I bought, my research said all 335ds - SE or M Sport - came with M Sports suspension.

Made sense, same situation with my Z4.

...however it turned out that was the case, for the E92 (coupe) - not the E91!

A suspension refresh is more work than I should probably take on right now (as my wife reminds me - this is not a project car), but I thought the M-Sport spec front anti-rollbar would sharpen the front-end a little.

I don't normally like to mess with anti-rollbars as unless you do it right you can end up inducing the opposite behaviour you want, but in this case I'm not looking for outright grip, just the front end to feel a little better when not on the limit.

Plus, the car already has an M-Sport rear anti-rollbar from the factory - this is included when you get a sunroof (presumably due to the extra weight). So really I'm just balancing it up...

In BMW fashion, you can often find the part you need on a completely different car - so I got one off an X3, but the same part number.

It turned up with drop links and bushes, which I binned.

The bushes put up a fight - they are just the basic rubber D-shaped ones you'd find on most cars but they were stuck fast and I had to chisel them off.

They had stuck to the bar with a slightly stretchy consistency.

I'm not sure what process causes the rubber to go like that, but it looked a lot like they'd worn, and someone had pumped them full of silicone to remove the play. Maybe I'm just suspicious...



Some wire wheel action later and it's looking better



And some new powerflex bushes as well



Edited by Jakg on Monday 7th August 21:55

Jakg

Original Poster:

3,463 posts

168 months

Friday 31st July 2020
quotequote all
Been busy with DIY so a pretty small update.

First MOT in my ownership was a clean pass, which was nice.

You can fit 2x 1 ton bags of garden waste in the boot, although it was completely full.
Stupidly I left it overnight so the car is full of bugs...



Also tried out the removable towbar - fitting was ridiculously simple. And I even found a receipt for it being fitted to the car for £650!

Annoyingly I had to loosen a bolt to swing down the electric socket - not sure if that's to be expected with a removable towbar?


Jakg

Original Poster:

3,463 posts

168 months

Saturday 12th September 2020
quotequote all
Jakg said:
A suspension refresh is more work than I should probably take on right now (as my wife reminds me - this is not a project car)
On that note...



Got a great deal on a Bilstein B12 pro-kit (shocks & springs)

At the same time I also upgraded to M3 front wishbones - more camber and better bushes/ball joints - this requires the M3 headlight level sensor too.

When you add new shock mounts front & rear and some nuts / bolt - then it's a lot more £££ than I initially realised!

Most of the suspension came apart easily, although the design is a little more complicated than you'd find on say an E46 as there are almost two wishbones - no more complicated than my old Megane though.
One of the wishbones wouldn't pop out of the hub (BMW term - "wheel carrier") no matter what I did, and I couldn't find my ball joint press on it as it was too tall - I ended up cutting the top off it to get the tool on, but the heat from cutting it loosened it up anyway.
Also, your mean to be able to counterhold the nut on the arms with a torx bit - but when I tried that using a spanner on the nut and my impact wrench on the torx head, it was my torx bit that lost!





The TRW wishbones are the BMW part with the logo ground off



Front strut disassembled



New ones built up



Rears were much easier - once I'd dismantled all the interior to get to the top mounts





With the wishbone / guide rod / track rod end and now strut removed, the hub was unsupported with the disc and caliper attached - which meant it was very heavy. Although I used the jack to take the weight, not only was it really awkward, but I caught the disc backplate on something.



The fold is no big deal, but it pulled through bolts, too.

A new one was quite expensive, but I really needed the car back on the road so I needed to have a proper look.

Tried to remove the brake disc and the head of the bolt immediately rounded despite doing all the right things.

I tried tapping it round with a chisel which worked on my Z4, but didn't really seem to work here.

Settled for hammering a T45 in there instead which came out without fuss.



With the disc off, it's clear whats happened





Some repair washers later



With the suspension done, there were some other jobs to attend to while it was in the air

Brake warning light was on, despite both sets of pads being ok.
I've reset the light through the computer, but it doesn't take the warning away unless the sensor is actually disconnected / reconnected to prove you've done the work.
Both sensors were damaged so I replaced them - the front sensor wasn't even attached to the caliper and was just hanging loose, broken.
I'm not quite sure on the cable routing btw.



Also flushed some new brake fluid through



I'd also been hearing a "whooshing" sound under acceleration - I presumed it was a vacuum leak but when I took the undertray off I could see the new boost hose had popped off.



The o-ring had somehow split



I worked out the problem was probably the "lip" on the intercooler needs to be fully removed (i'd just loosely cut a bit off the end) to ensure the connector is fully fitted.

I contacted MTC to get a new o-ring - they mentioned this regularly happens if you install without lubrication. Maybe it wouldn't happen so regularly if they included instructions (I originally used lubricant when installing btw).

Again, I needed the car now so I used the o-ring off the standard hose to re-assemble, but theres no longer a visible gap between the intercooler and connector



Finally with the airbox off I put a Pipercross panel filter in




First impressions of the above are... terrible.
The wishbones are longer to introduce the camber, but therefore the track rod ends need adjusting out significantly to prevent massive toe.
I tried to bring them out a bit to make the drive to the garage pleasant, but I just couldn't shift them.
The drive there was horrible - it's crazy how bad you can make a car handle with some bad geometry.
The garage used oxy-acetylene to heat them up enough to adjust - you could hear that horrible dry metal thread squeak with every turn they made.

Once aligned - much better. Ride is clearly stiffer, but a lot of the vague and floatyness of the front end is gone.
There's a couple of teething problems I need to investigate before I can really explore it more though.

Jakg

Original Poster:

3,463 posts

168 months

Sunday 13th September 2020
quotequote all
Todays job - fuel filter.

I removed the old one to find the new one I'd bought had the end broken off!



So I'm now waiting for another...

Jakg

Original Poster:

3,463 posts

168 months

Thursday 17th September 2020
quotequote all
Jakg said:
Todays job - fuel filter.

I removed the old one to find the new one I'd bought had the end broken off!



So I'm now waiting for another...


Round #2 was much quicker with the car jacked that little bit higher.
Jakg said:
I'd also been hearing a "whooshing" sound under acceleration - I presumed it was a vacuum leak but when I took the undertray off I could see the new boost hose had popped off.



The o-ring had somehow split



I worked out the problem was probably the "lip" on the intercooler needs to be fully removed (i'd just loosely cut a bit off the end) to ensure the connector is fully fitted.

I contacted MTC to get a new o-ring - they mentioned this regularly happens if you install without lubrication. Maybe it wouldn't happen so regularly if they included instructions (I originally used lubricant when installing btw).

Again, I needed the car now so I used the o-ring off the standard hose to re-assemble, but theres no longer a visible gap between the intercooler and connector

When I contacted MTC, I was advised the new O-Ring is 0.5mm bigger. Doesn't sound like a lot but it was really, really tricky to get enough force on to fully seat the connector, and then put the clip on to hold it in place.
Lotusgone said:
I don't half envy your pan roof.
If it's any consolation, it broke a couple of months ago and wouldn't close!
I had to leave it open and keep an eye on it at work until I could get home to work out how to manually close it.
I've tried recalibrating it but without much success - the glass isn't sitting right.
My next job is take the glass out, see whats going on and cover it in the special BMW lube (which is like £10 a sachet).

For the time being it tilts (which, until I tried recalibrating, I had no idea it did), but doesn't slide.
I would warn any future owner that the sunroof lets in a lot of noise - even when closed. With the shade back the difference is noticeable.

Looks good from above, though



Edited by Jakg on Thursday 17th September 21:07

Jakg

Original Poster:

3,463 posts

168 months

Thursday 17th September 2020
quotequote all
stevemcs said:
WIX filter by any chance ? we won't use them on BMs anymore - fuel filters only.
First one was Mann, second one was a genuine BMW one... which was also Mann.

Jakg

Original Poster:

3,463 posts

168 months

Wednesday 30th September 2020
quotequote all
The drop links were I think the original part so I swapped them for some new Meyle HD ones.

Simple job, especially when it's all been apart recently.

Except for when you somehow drop one of the nuts inside the hub of the brake disc and need to take the caliper + disc off to remove it. Twice!

Note how the original was slightly bent.
Ball joints didn't have any play but did seem very loose off the car.



I've also realised pretty much every picture is of it in some state of repair, so here's one of the new stance.
Lowering was an unintended side effect but the ground clearance still seems ok.



I'm still undecided on how I feel about the suspension - the ride is less forgiving but clearly tauter.
But a more agile front end does exacerbate the fact it's a large heavy car, and you can feel the weight more.

That, combined unsupportive SE seats, poor mismatched tyres and autobox does make it feel a little confused sometimes.

Hopefully some more time in the car and a little more work and i'll change my mind!

Jakg

Original Poster:

3,463 posts

168 months

Thursday 1st October 2020
quotequote all
DailyHack said:
I fitted a £100 M-Sport Alacantra seats/interior in my 2012 SE E91 easy fit and somewhat more exclusive than leather.

Made the world of difference and so adjustable, the standard SE seats are/were terrible I don't miss them one bit - sold the whole lot for £15 biggrin
I'm on the lookout for some sports seats, the current ones are heated so I don't want to lose that which makes it a bit trickier.

I did make a start on fitting some Corsa VXR Recaro seats but that was one project too far.

Jakg

Original Poster:

3,463 posts

168 months

Tuesday 27th October 2020
quotequote all
Over the last 2k miles it's averaged 37.6 MPG which is, well, pretty rubbish really.

I'd read all the horror stories on economy before I bought it but just couldn't believe a modern diesel could be that rubbish.

Good job that working from home / COVID has shrunk my mileage massively - I could probably afford to run a petrol estate instead now, but looking back I'm not sure what else would've fitted the bill without being way worse (i.e. S4).

Dad-wagon duties settling in well.



Bit of a pain getting the buggy in the back though - keep browsing eBay for F11 535ds...

Jakg

Original Poster:

3,463 posts

168 months

Wednesday 18th November 2020
quotequote all
Some boring updates.

The car came with 2018 maps and the seller suggested I should update as it was easy.

You can update via a USB stick and you can download the maps online, but they need a VIN-locked activation code (FSC) - unique to your car.

Unfortunately, I couldn't get this to work.

As I have a retrofitted CIC iDrive system, the car has two VINs - the VIN of the physical car, and the VIN of the CIC system (it's out of a 2011 Russian 320xd apparently!).
To allow these units to work together, some kind of patch has been installed to bypass the VIN check - and the side effect of this is whatever FSC code you use (even one I bought), it doesn't work.

I asked for help online, but I was disappointed to find very little freely available information - retrofitting these systems is a profitable business it seems, and instead you just get "PM me" comments and they couldn't even really help.

Someone eventually pointed me in the right direction, and using a piece of software you can temporarily bypass the FSC check in the car, enough to upgrade it.

https://www.e90post.com/forums/showpost.php?p=2685...




Next problem - the USB port in the car (for media) has never worked.

I assumed it was a coding error, but it was eventually pointed out that when the CIC system was fitted, two existing modules - MULF & TCU - were removed, replaced with a Combox - a media unit that does Bluetooth etc.
These all live under the boot floor, where you might otherwise expect a spare tyre to live.
However, only the cables that went to the TCU were ever connnected to the Combox - the MULF cable (blue) wasn't connected.

It's not a straight swap and a changeover cable was made when it was first fitted (red wires).



Kufatec sell a plug&play retrofit loom, very expensive for something you could easily make yourself (£90!) but at the moment I want little hassle.

Unfortunately while it's plug and play, you need to connect to CANBUS - a little way further around the boot and theres some spare CAN wires, helpfully isolated as they are connected to the trailer socket wiring.

Not the neatest job as all the cables are too short, but connected up and it worked first time.



Unfortunately, it turns out USB is pretty useless - Bluetooth seems more reliable, and the USB port doesn't really have enough power to charge my phone.
You can use the BMW ConnectedApp to put destinations in which is handy though - but only when plugged in.

One benefit of a working USB port was the ability to upgrade the Combox software - again getting hold of the update was more hassle than it needed to be as the BMW website recognised neither of the VINs I had.




Don't worry, oily bits will be coming next time.

Jakg

Original Poster:

3,463 posts

168 months

Monday 23rd November 2020
quotequote all
Oily update.

After replacing the glowplug controller, I still had a two glowplugs showing a fault on INPA.

One frustration is that the engine is so far back, you have to remove quite a lot from the bulkhead to be able to remove it.



Some of the plastic you have to remove.



You also need to disconnect the battery to remove a power connector.
The battery is in the boot.
The boot release is electric.
Don't disconnect the battery and then close the boot!
I tried the emergency release but it didn't work - luckily I could reconnect the battery to get the boot open - after climbing through the car.

When removing the inlet manifold, I managed to drop a nut - couldn't be bothered to jack the car up and retrieve it so bought another.

I'd read about the glowplugs being difficult to remove so I gave the car a good run first to get it nice and hot.
I also used a torque wrench set to 30nm to remove them - the glowplugs have a snapping torque of 35nm so theoretically it's impossible to snap them this way.
Luckily they came out very easily.



They are very oily - I suspect either the inlet manifold gaskets or swirl flaps were leaking oil - but luckily this meant the threads were well lubricated!
Replaced all 6.

With the inlet manifold off I gave it a clean.

I also checked the swirl flap actuation but all good - not a fan of removing them.

Finally I replaced the gaskets - probably unnecessary but the old ones had hardened significantly.





All of the "collets" on the inlet manifold separated from the little rubber gaskets and I couldn't get them back together by hand.

I had a brainwave and a little clamp did the job



Remember the bolt I dropped during disassembly? Well I dropped it again so waiting for another!

With the engine in bits I also had a go at the vacuum lines.

The car has a twin sequential turbo setup, with quite a complicated pneumatic setup for operation.
It's plumbed together with vacuum hoses but they can deteriorate causing boost issues.
I didn't have any problems, but it seemed prudent to try tor replace them.



I only managed to get a couple done - I couldn't work out how disassemble the pressure converter assembly to go any further.
Of the hoses I looked at, the ones at the back with the pressure converter were fine - I think it's only the area around the turbos were things start to deteriorate - of those I managed to replace three of the four.

I don't think the old hoses were leaking, but they were chafed and oddly solid in the bends



Back together and after an eternity, it started - I was worried I'd done something wrong. I think the battery is on it's way out.
It still runs so I guess that's something!

Jakg

Original Poster:

3,463 posts

168 months

Tuesday 24th November 2020
quotequote all
dhibbert said:
Is there a reason to leave the swirl flaps in there? I bought the blanking kit for my F01 730d and upon removing the manifold etc. 2 of the 'flaps' were missing! One we found when blasting clean the manifold, the other we never recovered and has either passed through the engine (unlikely) or has lodged in the intercooler area where it hopefully remains!
I think some engines are more prone to swirl flap issues than others - I think the later ones were more reliable. Certainly I've not heard of a 335d killed by them.

Plus, they are there for a reason - I know loads of people say they don't notice a difference, but BMW didn't put them there for fun and one of the TIS documents explains in more detail the benefits.

There's a similar argument about the DISA valve on the M54 engine as found in my Z4 - I'm not convinced there either!

Divisive opinion though, I know, and I can see why people do it.
If any of the flaps were damaged I might feel differently, though...

Jakg

Original Poster:

3,463 posts

168 months

Monday 7th December 2020
quotequote all
The E9x platform came with several audio packages (in order of quality):

Base,
HiFi,
Top HiFi / Logic 7 / Harman Kardon,
Individual Audio.

My car has the "HiFi" package and it's alright - the underseat subs add depth I'm not used to with standard sound systems.
In the past I've fitted subs, amps etc, but I'm used to cars coming with a DIN headunit, and four crap speakers - obviously this is a lot more complicated.
I did see the entire Top HiFi system come up for sale, but decided that was a bit too much of a project.

I found some Logic 7 mid speakers on eBay cheap and picked them up.
I also bought the tweeters at the same time, but due to a mixup the seller sent only one so I didn't fit them.

Always hated taking door cards off, but to be honest these are probably the simplest I've done - trim pulls off, couple of torx screws and then a bunch of trim clips to pop off.
Even more surprisingly, I didn't even break any clips!

Speaker attached to the door card (boo) with some nuts



New vs old



Back together and I can't say I can tell much difference...



The car has front & rear parking sensors, and the iDrive shows a nice infographic of the distance each sensor reports.
However, a camera would be much handier - fitted several before and it's never fun.

This one however, was quite a bit harder than I expected.

I found a neat camera which integrates and replaces the existing boot handle.
You obviously need to run power & signal wires down the car.

On my Megane I ran it on the trim behind the window, but this is complicated by the split rear window - the window can be opened independently of the boot, which means that there is no "inside" of the boot lid to run wires in past the rear window.
Instead they just sit under some plastic trim, and there's not much space in there for more wiring.
Plus of course getting the wiring through the existing grommets is always very unpleasant.



The tailgate trim is ridiculously heavy - when removed it's actually hard work to shut the boot because of how stiff the gas struts are to compensate, due to all the sound deadening.



In the past, in the dash end it's a simple affair of connecting the trigger to the reversing lights and plugging in an RCA connector, but not so here.



Here, because iDrive, you need an emulator to allow a reversing camera to be connected (~£40).
This box of tricks powers the camera, with no connection to the reversing lights, and is required for the car to do the work.
The RCA plug gets cut off and connected to some pins on the back of the CIC unit
After some coding - hey presto?

I followed this guide - https://www.e90post.com/forums/showthread.php?t=10...

Unfortunately, the first emulator I bought was bad - it was a plug&play unit and I think it was wired up wrong, plus it was missing the power wire for the camera.
After doing the coding (nb - I hate that phrase - but you know what I mean), when going into reverse nothing - not even the parking sensors - came up on screen.

I bought another emulator, this time not a plug&play one, but had the same problem!
This was months ago but finally got around to having another look, and having found a poor connection, and different pinout of the connector (swapping CAN+/-), I had another go.



This time, I get the display - but still no camera...

When fitting the camera, I grounded off the boot interior light - but I didn't actually test it first.
Somehow there wasn't a ground there at all so I swapped to the tail light ground (testing it this time...) and...



It integrates really well with the iDrive system (obviously).
A really neat feature is that because there's front parking sensors, even after you shift out of reverse, the parking sensors stay on until you pull away properly - and as the camera is wired into the emulator, it stays on too.

It also makes lining it up for the trailer really easy.





Jakg

Original Poster:

3,463 posts

168 months

Thursday 10th December 2020
quotequote all
Jakg said:
After replacing the glowplug controller, I still had a two glowplugs showing a fault on INPA.
And after changing them... now I don't.


Jakg

Original Poster:

3,463 posts

168 months

Saturday 26th December 2020
quotequote all
The autobox has "adaptation" values that show how the gearbox is correcting for wear in the transmission, which allows you to get an idea for it's overall health.

In my case, those values are not great - especially on "Clutch E", which is a common failure point on this gearbox (ZF 6HP26).

With that in mind, I didn't want to push the car any harder - i.e. an engine or gearbox remap - unless I could get those numbers down.

I've mentioned before I've not had any real problems with the gearbox, my only issue was when trying to park it seemed to take more throttle than you'd expect to get it moving and it wasn't very smooth doing so.

It's ironic, as my Megane was on it's original clutch, and at 100k I put on a bigger turbo, decat, DPF delete and a remap. After some abuse on an autosolo it started slipping, and I wrote it off as one of those things that happens when you tune cars and was happy to get it replaced.
But somehow being able to monitor the health of the box in advance makes me super cautious.

One suggestion was to service the gearbox.
It's a classic case of BMW saying the gearbox is sealed for life, but the gearbox manufacturer recommends a service every 60k.

A "service" in this case means a replacement oil & filter (integrated into the sump) and a mechatronic sleeve - this seal around the electrical connector between the car and the gearbox's mechatronic unit that actually does the hydraulic actuation of the mechanism.

I bought the genuine ZF kit that includes the above, plus new sump bolts and a new filler plug.
Pricing for this was all over the place - I paid £150 from AutoDoc, but ECP sell it for about £300.



I took it a step further and also bought the tube and bridge seals (I doubt thats the technical name) which wear over time and not seal as well, causing the gearbox to work harder than it needs to and leading to higher adaptation values.

Mechatronic sleeve top right, bridge seal top left, tube seals on the bottom.



A guide on the job can be found here - https://www.youtube.com/watch?v=dCvmdo1bLLw
The job itself (shouldn't) be too hard, but the filling is a pain.
My pictures get progressively worse, the more gearbox oil I've spilled on my phone...

First attempt at this job did not go well - my jack broke!

Second attempt started off badly - my Z4 has died and is immobile so to get enough space I had to jack it up in a different part of the drive, which wasn't really suited to it.

Got the car high (or at least, as high as I can on the drive!) and level.



Oil drained out - quite black.



Sump off - original dated part. Magnets were clean.





Mechatronic unit removed



Tube seals were a little worn, but not too bad
I stabbed myself in the hand quite badly removing them with a pick - nevermind, ATF oil is good on open wounds, right...?



Bridge seal was a bit flat



Went to put the new sump on, can you spot the problem?





One snapped oil pickup.

If you look at the first picture it turned up like that, but wasn't obvious frown

Already drained all the oil out by this point so didn't really have a choice but to continue.
Cleaned up the old sump, drained it as best I could, took all the seals and sump plug from the new sump to the old one.

The mechatronic sleeve was a real pain.
I could just about get a screwdriver in there to unlatch the connector, and pull the old sleeve free to drop the mechatronics unit.
But the seal is rigid and there wasn't enough space to actually get it out, or a new one in.



I had to use the jack to support the gearbox, with a lump of wood going up through the gearbox mount, onto the gearbox mounting frame.
Then I could remove the gearbox mount.
And then finally I could remove the bolts holding the exhaust hanger bracket so that I could remove it to give me enough space to get the sleeve out and the new one in.
Absolute nightmare.



Finally, with it all reassembled, I could refill.

The process is - fill until overflow, put the plug in, cycle through the gears, get the gearbox up to "operating temperature" (30-50° C), remove the plug and fill again until overflow.

I put in about 4L of oil - I've got a little bottle pump which is really handy, but it's hard work pumping that much through



You can monitor the gearbox temperature through INPA, or you can just use an IR thermometer on the sump.



I did this in the middle of December - it took nearly an hour to warm up, which I wasn't expecting.

Once warm, I struggled to add more - I needed to add it quickly to avoid the gearbox getting too hot, as then I'd need to let it cool down before I could continue refilling, so I had to pump another 1.5L quickly.
You have to do this process with the engine running - if you turn it off, the "extra" fluid comes out and you need to add some more (don't ask me how I know)

Despite being the official method, dropping the sump only changes the oil in the gearbox - the oil in the torque converter is left alone.
You can pump it out using a fancy machine, but I was happy with how much I replaced - especially after spilling a load - what was coming out wasn't clear like new oil, but it looked nothing like the oil I'd originally removed.

The least pleasant part was putting the fill plug in.
It's at a slightly awkward angle, and very close to the transmission tunnel.
You need a good grip, while 40° C transmission oil is coming out and soaking your gloves (with an open wound courtesy of earlier)
At the same time, the back of your hand is gently brushing the exhaust of a car that's been running for an hour.
This was not fun!

All in, it took me about 5 hours (but I'm very slow).
And re-affirmed that I really hate working on the drive, when its wet and cold getting covered in crap. I need a garage!

It seems smoother when driving, not a night-and-day difference, but its definitely smoother to change, and seems less hesitant pulling away.

I drove it for a hundred miles or so and read the adaptations.
The quickcharge pressure on clutch E should be below 400mbar, and the quickcharge time under 40ms.
Before:



After:



Yep.... after all that work, it's basically the same!
So no remap for now... I'll keep an eye on it.




On a slightly cheerier note, I replaced the windscreen wipers.
Aero units were fitted, but had been fitted upside down so the aerofoils just made noise instead of doing anything useful.