E60 530d Boost/misfire/fluctuation problems. Help please!

E60 530d Boost/misfire/fluctuation problems. Help please!

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joropug

Original Poster:

2,547 posts

188 months

Tuesday 5th August 2014
quotequote all
I have a couple of minor issues

1) at 70 mph whilst cruising, I get a slight misfire/boost fluctuation. I'm assuming it's not the common gearbox tc/mechatronic fault because the revs don't bounce around etc. *This is very minor, almost like when using cruise control it accelerating and decelerating very slightly to compensate for a road gradient. You struggle to see the needle change. You can feel the car slow down slightly and then resume, this is less than half a second or so. Does not occur when accelerating, purely on cruising.


2) I think the same issue as above, in second and third gear if I hold the revs at about 1700 to 2500 and accelerate slowly, I can hear the turbo spool increasing and cutting out, I. E whoosh, whoosh, *whoosh... Again like a misfire/boost issue

Both occur on very light load, I can drive the car hard and it's smooth as silk. If I'm accelerating or decelerating it doesn't occur. It is worse on cruise control. Makes no difference in manual or drive.


I've hooked up my Android phone to bluetooth adapter and used torque. App. Boost will peak at around 22psi and is around 1.5 to 2.5 cruising. I tried to see if the fluctuation affected it and want to say it did but the difference is minor so might not have.



I've recently had both thermostats done, and the DPF is now noticeably regenerating every 7 to 10 days so hopefully this isn't the issue. The car was used by a mother so I'm guessing it's done more town driving than most. Car got scanned and had a couple of glow plugs out being the only issue which I'm told doesn't affect the drive. (but oddly was told it wouldn't regenerate the dpf with two out.....)


I plan on changing the air filter, which I'm presuming when out reveals the EGR so I can clean? I've also had it suggested it's the vacuum pipes but I wasn't sure where to look for these.


Any help appreciated and pictures to aid my diy service too.

Ruxpin

324 posts

244 months

Wednesday 6th August 2014
quotequote all
joropug said:
I have a couple of minor issues

1) at 70 mph whilst cruising, I get a slight misfire/boost fluctuation. I'm assuming it's not the common gearbox tc/mechatronic fault because the revs don't bounce around etc. *This is very minor, almost like when using cruise control it accelerating and decelerating very slightly to compensate for a road gradient. You struggle to see the needle change. You can feel the car slow down slightly and then resume, this is less than half a second or so. Does not occur when accelerating, purely on cruising.


2) I think the same issue as above, in second and third gear if I hold the revs at about 1700 to 2500 and accelerate slowly, I can hear the turbo spool increasing and cutting out, I. E whoosh, whoosh, *whoosh... Again like a misfire/boost issue

Both occur on very light load, I can drive the car hard and it's smooth as silk. If I'm accelerating or decelerating it doesn't occur. It is worse on cruise control. Makes no difference in manual or drive.


I've hooked up my Android phone to bluetooth adapter and used torque. App. Boost will peak at around 22psi and is around 1.5 to 2.5 cruising. I tried to see if the fluctuation affected it and want to say it did but the difference is minor so might not have.



I've recently had both thermostats done, and the DPF is now noticeably regenerating every 7 to 10 days so hopefully this isn't the issue. The car was used by a mother so I'm guessing it's done more town driving than most. Car got scanned and had a couple of glow plugs out being the only issue which I'm told doesn't affect the drive. (but oddly was told it wouldn't regenerate the dpf with two out.....)


I plan on changing the air filter, which I'm presuming when out reveals the EGR so I can clean? I've also had it suggested it's the vacuum pipes but I wasn't sure where to look for these.


Any help appreciated and pictures to aid my diy service too.
My 335d does something similar. If the revs are around 2000 to 2250 rpm and very light throttle you sometimes get a judder through the transmission which feels like a miss fire. I sometimes notice it driving steadily through 30 or 40 mph zones.

It was most noticeable and disconcerting with cruise control set at 80mph on the french autoroutes a couple of years ago. As you went up and down hills and the throttle input was automatically varied the judder/hesitation was particularly strong. BMW investigated and came up with some BS excuse.. something like harmonices of the flywheel....not under warranty sir... To me it feels much more like a miss fire or turbo actuator issue than flywheel.

I think i had the issue both before and after changing thermostats (would need to check my records), but interestingly i haven't noticed it recently, although I haven't driven in europe and sat on cruise for hrs at a time for a year or so.

When the dpf is regen-ing you often get a similar judder under light throttle and low speed.

Sorry no help but i think we have a similar quirk


Edit to add: Just seen your note about vacuum pipes. I did have most of these changed (most as one was a real pain to access without taking everything apart). I will check when these were done and try and get the car to do the judder again. Maybe changing the vacuum pipes has helped resolve this... (the vacuum pipes was fairly expensive job. Pipes are expensive from bmw for what they are and it is a slow and fiddly job - my mechanic also found a oil leak on the big turbo oil feed...but at least we caught that before a bigger bill...)



Edited by Ruxpin on Wednesday 6th August 09:16

joropug

Original Poster:

2,547 posts

188 months

Wednesday 6th August 2014
quotequote all
Thanks for your reply – I’m finding it really difficult to get solid answers because most of the forums are American and the diesel lumps aren’t popular there.

Have you had your EGR replaced? Mine drove no different after having the thermostats done, apart from the DPF regeneration occasionally taking place.

I absolutely dread to think it could be the transmission – If you youtube cattle grid e60 transmission, you can see that at cruising speeds when the gearbox is worn, the needle jumps about where it cant lock in the gear. Mine doesn’t do this but it its most noticeable at the same speed.

Because it happens in lower gears though, at the same RPM, I think it is much more likely to be on the engine side. What variables are there?

Injectors – Youtubed injector fails and the engine taps etc, mine is smooth and doesn’t judder or misfire on idle.
EGR – Getting my head around how this might affect it, I don’t know if it could? Saying that it if it is gunked up, then the EGR valve might be struggling to stay open partially. I.e. opening fully or not at all?
Air filter – Checked mine, not in too bad a state and can’t see how this is an issue.
Glow plugs – I do have 2 out, but I’m told this doesn’t affect the drive once warmed up.
Transmission – If the transmission were going, I’d expect to feel more substantial movements as videos suggest.
Turbo – My turbo is quite loud, I have had turbo petrol cars before and it sounds like them (TT’s) after a remap. Not concerned about the turbo being worn as the noise is consistent with what I’m used to but is the boost being lost? Waste gate or something? I know when I replaced the recirc valve with a semi-recirc on the TT the performance was hampered.
MAF – Would it not affect all of the rev range?

Ruxpin

324 posts

244 months

Wednesday 6th August 2014
quotequote all
joropug said:
Thanks for your reply – I’m finding it really difficult to get solid answers because most of the forums are American and the diesel lumps aren’t popular there.

Have you had your EGR replaced? Mine drove no different after having the thermostats done, apart from the DPF regeneration occasionally taking place.

I absolutely dread to think it could be the transmission – If you youtube cattle grid e60 transmission, you can see that at cruising speeds when the gearbox is worn, the needle jumps about where it cant lock in the gear. Mine doesn’t do this but it its most noticeable at the same speed.

Because it happens in lower gears though, at the same RPM, I think it is much more likely to be on the engine side. What variables are there?

Injectors – Youtubed injector fails and the engine taps etc, mine is smooth and doesn’t judder or misfire on idle.
EGR – Getting my head around how this might affect it, I don’t know if it could? Saying that it if it is gunked up, then the EGR valve might be struggling to stay open partially. I.e. opening fully or not at all?
Air filter – Checked mine, not in too bad a state and can’t see how this is an issue.
Glow plugs – I do have 2 out, but I’m told this doesn’t affect the drive once warmed up.
Transmission – If the transmission were going, I’d expect to feel more substantial movements as videos suggest.
Turbo – My turbo is quite loud, I have had turbo petrol cars before and it sounds like them (TT’s) after a remap. Not concerned about the turbo being worn as the noise is consistent with what I’m used to but is the boost being lost? Waste gate or something? I know when I replaced the recirc valve with a semi-recirc on the TT the performance was hampered.
MAF – Would it not affect all of the rev range?
Just watched the "Cattle grid transmission" - mine doesn't do that thankfully!!, the fluctuations are much more subtle in my car, many people might not even pick up on it, but being OCD i notice it.

EGR not changed on mine. Only things i have had done are red boost hose and seals, both thermostats, vacuum hoses, turbo oil feed line, gearbox adaptations reset (needs doing again - grr)

I thought it was a quirk of the 2 turbo setup on the 335d - at least i can rule that out!

My car is now on 110k and engine/gearbox wise drives the same as it did when i got it at 50k. (At 50k it had jerky changes in DS 1-2 and 2-3 under light throttle which were solved by bmw resetting the adaptations but 40k later it is starting to come back)

I might have just learned to live with the light throttle stuttering as i haven't noticed it much if at all recently. I will have a go to trigger it later and report back, it might be that the vacuum hose work helped...

joropug

Original Poster:

2,547 posts

188 months

Wednesday 6th August 2014
quotequote all
Thanks for the reply.

Would be interested to hear if yours does it on very light acceleration, in second gear for instance at around the same rpm?

Ruxpin

324 posts

244 months

Thursday 7th August 2014
quotequote all
joropug said:
Thanks for the reply.

Would be interested to hear if yours does it on very light acceleration, in second gear for instance at around the same rpm?
I "think" it is still doing it. My commute is 22miles of b-road so difficult to repeat the steady on/off at constant speed that seemed to trigger it most previously. I will keep trying though.

I thought i felt it this morning whilst in "M3" coming off the throttle at around 2500 rpm and then gently back on at 2250 rpm. "Thought" as it isn't as strong a miss/stutter etc as i used to experience in 6th on the autoroutes.

I'm not technically up on how the auto/TC works so excuse the lingo..I may also be way off with how the thing works!.... It seems to happen when you ease off and "freewheel" from around 2250-2500rpm and then judders/hesitates when you go back on the power gently. Does the TC "unlock" and allow the car to freewheel at around this rpm and then judder as it locks back up? It does feel very much like a miss fire though with no slurring of gears or movement on the rev counter.

Ruxpin

324 posts

244 months

Friday 8th August 2014
quotequote all
Journey home yesterday - DPF did a regen which gives a very similar hesitation/stutter under light acceleration just more noticeable/violent and throughout the lower rev range.

To work today and yes my car is still doing it - i think i managed to repeat it in 2nd, 3rd and 4th gears whether in D, DS or M mode. It seems to happen between 2000 and 2250rpm and on very light throttle application after being fully off throttle. It is a much more gentle hesitation/stutter than when the dpf is regen-ing.

I think I have learned to ignore it. At the lower speeds/gears it isn't too bad and really only noticeable to an OCD person!. At 80mpg on cruise control in 6th it used to be quite worrying - first few times it happened i thought it was going to conk out..



Edited by Ruxpin on Friday 8th August 12:40

joropug

Original Poster:

2,547 posts

188 months

Wednesday 20th August 2014
quotequote all
Sorry for the delayed reply.

I've been speaking with a top bloke, Sean at Iridium Engineering in Southampton. Has a great rep on forums. Very knowledgable.

Withouth seeing the car, he has suggested one thing that it may well be that we haven't listed.

Variable turbo vanes clogged up with soot.

Apparently it's quite common and he said it could be causing the veins to jump suddenly/not move correctly under certain loads.



He has suggested a "revive product" that you spray into the intake which will de-coke it and clear it out to an extent.

Sounds like a highly plausible cause.

http://www.iridiumengineering.co.uk/

joropug

Original Poster:

2,547 posts

188 months

Wednesday 20th August 2014
quotequote all
Is yours on it's original Turbo (s)?

hman

7,487 posts

193 months

Wednesday 20th August 2014
quotequote all
this is why I sold my BMW too many faults where nobody could come up with a definitive answer and instead expected a trial and error replacement of extremely expensive parts.

I px'd mine in the end, but it was fluctuating at low speed (like surging) which if you did a software induced leakoff test resolved the surging - of course the car couldnt be driven with the laptop connected all the time though!!

It is thought that mine was the pressure regulator on the fuel pump or duff injectors, but both options were expensive and didnt guarantee a cure.

get a copy of bmw technic and you can see a lot of parameters whilst you are driving which could indicate the problem.

z_chromozone

1,436 posts

248 months

Friday 22nd August 2014
quotequote all
My 58 530D does this as well at ca. 2000 rpm, usually on the motorway cruise. I had assumed it was a worn throttle potentiometer. Mine has a manual box and 185K on the clock, so not an auto gearbox problem.

I have also been suspicious that manufacturers also create lean spots in the fuel maps at certain speeds to up mpg in their tests. My old Mondeo used to have the same.

Ruxpin

324 posts

244 months

Friday 22nd August 2014
quotequote all
z_chromozone said:
My 58 530D does this as well at ca. 2000 rpm, usually on the motorway cruise. I had assumed it was a worn throttle potentiometer. Mine has a manual box and 185K on the clock, so not an auto gearbox problem.

I have also been suspicious that manufacturers also create lean spots in the fuel maps at certain speeds to up mpg in their tests. My old Mondeo used to have the same.
Very interesting that it affects the manual - thanks for the info.

It's not a problem as such, just an annoying quirk to an OCD person once you know it is there

Ruxpin

324 posts

244 months

Friday 22nd August 2014
quotequote all
joropug said:
Is yours on it's original Turbo (s)?
Mine are the original turbos and actuators etc at 110k.

It has had the "fault" for as long as I can remember (acquired car at c50k).

I haven't used any specific injector cleaner type products but do occasionally use Millers Diesel Power Ecomax.

I can imagine it affecting a lot of cars but not being noticed by many owners as it is quite a subtle thing. Maybe it is a bmw emissions/mapping thing (afaik mine has not been remapped)

joropug

Original Poster:

2,547 posts

188 months

Saturday 23rd August 2014
quotequote all
Just did a 50mph motorway cruise, of course on Germany autobahn network, at 75 to 90 mph and it did not do it once.

Slowed down to 70 mph and it started doing it immediately

joropug

Original Poster:

2,547 posts

188 months

Sunday 21st September 2014
quotequote all
Guys

Result...I think.


Someone on the forums bought a cheap MAF sensor off ebay to fault find and it resulted in what seems to be the same issue I'm having disappearing.


Rather than go down this route I decided to unplug my MAF sensor as this is a good diagnosis start (why didn't i do this sooner?)

Anyway. My issue around town on light throttle was all the time, not intermittent . Guess what, just drove for 15 minutes trying to replicate it and it did not do it once. I could do it with my eyes blindfolded before.

I haven't got up to speed to test out the 70mph issue yet, but I'm hoping that's resolved also..


I have a theory why it only affects light throttle, the car on WOT has tons of air passing the MAF, therefore minor fluctuations in readings wouldn't really affect it... But under light throttle acceleration and cruising, changes to the readings would be much more noticeable..



I will keep you posted after a week of driving. All being well I'll buy an oem MAF sensor from Bosch.

Ruxpin

324 posts

244 months

Sunday 21st September 2014
quotequote all
joropug said:
Guys

Result...I think.


Someone on the forums bought a cheap MAF sensor off ebay to fault find and it resulted in what seems to be the same issue I'm having disappearing.


Rather than go down this route I decided to unplug my MAF sensor as this is a good diagnosis start (why didn't i do this sooner?)

Anyway. My issue around town on light throttle was all the time, not intermittent . Guess what, just drove for 15 minutes trying to replicate it and it did not do it once. I could do it with my eyes blindfolded before.

I haven't got up to speed to test out the 70mph issue yet, but I'm hoping that's resolved also..


I have a theory why it only affects light throttle, the car on WOT has tons of air passing the MAF, therefore minor fluctuations in readings wouldn't really affect it... But under light throttle acceleration and cruising, changes to the readings would be much more noticeable..



I will keep you posted after a week of driving. All being well I'll buy an oem MAF sensor from Bosch.
Good work. Fingers crossed you have cracked it. How much is an oem MAF sensor?

joropug

Original Poster:

2,547 posts

188 months

Sunday 21st September 2014
quotequote all
Drove good hour or so didn't do it once so looks positive still. Like I said I could replicate it every time.

Oem 135 quid unfortunately hence wanting to leave it unplugged a little longer before investing.

Still, damn sight cheaper than other things it could have been and at least I'll know it'll fix it.

Worth unplugging your maf to see if it fixed it too

Ruxpin

324 posts

244 months

Monday 22nd September 2014
quotequote all
Is there any particular procedure to follow before disconnecting the maf? Engine off i assume? Is there any risk running without it? (Sorry, i don't usually do the spanner work)

joropug

Original Poster:

2,547 posts

188 months

Monday 22nd September 2014
quotequote all
Just unplug with ignition off.

You'll get an error code I cleared this with my android phone and torque app with a bluetooth adapter for obd, so not sure if it goes away by itself. Would imagine so.

joropug

Original Poster:

2,547 posts

188 months

Saturday 27th September 2014
quotequote all
Guys just an update on this resolution.

So I thought I had fixed it by unplugging the MAF, indicating that the MAF itself was faulty.

I was at a specialist today who I trust and showed him the symptoms, which he admitted he had not seen before. He said though he gets a lot of people phoning in saying they need a new MAF etc and it's rarely the problem.

The reason it has resolved the issue, is in his opinion, because the car will be running at default values hence has a knock on effect, for instance less boost pressure, etc etc.

anyway.....

I had the swirl flaps done today and I can confirm that this doesn't affect the problem.

However...Just sas I was leaving, I decided to unplug, and bung up the vacuum pipe operating the EGR (Which by the way, is squeaky clean on my car!!!) This has resolved the issue.

However, I don't want to get too excited as it could well be that again, unplugging the EGR has a knock on effect on something else.

But I think it's progress, and I could potentially just delete the EGR alongside the remap i'm looking to get.