White/ Grey smoke e36 m3 Help!

[MitchM]

Hi all,

I have a problem which I can't find. the car is smoking white/grey ish under acceleration also sometimes runs on 5cylinders mostly going in second gear low revs or it idles nicely sometimes you feel a misfire .

This is the list of things I've tried and what previous owner had done, I think it could be eighter the fuel pressure regulator or pump or knock sensors they look bad but don't trigger engine light.


1. New vanos
2. new Sensors cam vanos and crank
3. tappet cover gasket
4. new Cilinder head + head gasket etc etc
5. swapped out coil packs.
6.swapped injectors.
7. all vac lines replaced
8. fuel filter replaced.
9 .high pressure fuel pump ( previous owner replaced)

Also when up a hill it hesitates a bit really feels like it's under fueling

I'm hoping for some ideas here , maby some1 can help me I have a very tight budget this coming 2 months.

Thanks

 

[muhammedmanjoo]

Perhaps make sure that u got the right fuel pump in there, since u hadn't replaced it yourself

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Replaced it yourself

 

[Gizmo]

Have you done a compression and leak down test to see the state of the rings?

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I suspect burnt or broken rings.

 

[MitchM]

yep also did a compression and a leakdown test and that turned out 100%

but then if rings were shot it would smoke permanent.... it's only under load it smokes and sometimes runs on 5 cyl so I suspect fuel delivery being too poor.

only things that could cause such a thing is

pump
fpr
and knock sensors (retarding timing)

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when I take out the spark plugs cyl 1, 4, 5 , 6 seem a bit unhappy (dry) 2,3 wet (petrol) so im guessing mid knock sensor sending wrong signal ??

 

[tyu333]

Have you replaced the fuel filter? And the swapped injectors, where they new? Get the injectors cleaned.

Try and get codes read and it will help you with troubleshooting


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[A.C.SCHNITZER]

Have you done a compression and leak down test to see the state of the rings?

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I suspect burnt or broken rings.

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:withStu: Try do wet and dry tests. Your rings might be worn. Not forgetting valve stem seals

 

[Kubs]

HI Mitch

Had a similar issue with my car that displayed all the symptoms you mentioned minus the "white/grey smoke". I had also spent many thousands changing parts we thought where suspect, only to realize it was a silly plastic part in the below pic that needed to be changed.
I am no mechanic by any means but this is what I was told.Apparently when these clips are cracked or fatigued it does not engage the vanos correctly and causes all the symptoms you are having.

There are a few of them along the rail, I suggest you inspect all of them for cracks or fatigue and hopefully it is that because it is really cheap to replace.

Sorry for the vague response due to my limited knowledge but its definitely worth a shot.

 

[MitchM]

Hi all thanks for all great replied
The valve stem seals were done when I took the head of because I also suspected that.

I did some additional tests on the rings adding oil seeing if compression would improve but all turned out the same.

sticky piston ring maby but sure as hell no worn rings ... no oil usage.

I will check those links on the throttle bodies but mine aren't plastic S50 B30 engine so my intake bodies look a bit different but thanks for the new eye opener there.

Im gonna check and swap out 'the fuel pump and fpr and knock sensors to see whats going on

 

[Donovan2412]

Hi all thanks for all great replied
The valve stem seals were done when I took the head of because I also suspected that.

I did some additional tests on the rings adding oil seeing if compression would improve but all turned out the same.

sticky piston ring maby but sure as hell no worn rings ... no oil usage.

I will check those links on the throttle bodies but mine aren't plastic S50 B30 engine so my intake bodies look a bit different but thanks for the new eye opener there.

Im gonna check and swap out 'the fuel pump and fpr and knock sensors to see whats going on

PMed you

 

[MitchM]

ow and fuel filter is new injectors all cleaned tested and working 100% so its definitely 1 of 4 things now eighter ecu fpr or fp / knock sensors

 

[MitchM]

well I found out today what was/is causing the problem fuel pump and 1 bad knock sensor.. ...fuel pump cut out on the way home so it wasn't delivering enough fuel causing it to smoke instead poor combustion ...white / grey smoke. so looking for a replacement any one knows a price on those?