E46 330d turbo problem - pressure back into air filter

E46 330d turbo problem - pressure back into air filter

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H6CJF

Original Poster:

666 posts

192 months

Tuesday 19th July 2011
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Symptoms -

Black smoke on idle - not loads, but too much

Significant lack of power, mucho black smoke on initial acceleration and very 'juddery' at c 2000 rpm on light throttle

On boost, loud 'whooshing' - as if hose off / holed. However, removing the air filter, you find that the whooshing is coming back up the intake and therfore back through the MAF sensor.

Air filter is quite sooty.

I had 'whoosh' problems with this car a few weeks ago and found the inlet manifold split. Sorted that and it was fine for a while & now we have this.

The only other thing I have done recently is replaced one injector. (The injector IS exactly the same code) However, I fail to see any way this could be linked to what would appear (to me) to be a mechanical issue rather than an engine management problem.

Any ideas chaps cos at the moment I'm thinking Turbo.... ? frown

ETA it's a 51 plate 330d spt manual saloon done 160k

Edited by H6CJF on Tuesday 19th July 16:07

H6CJF

Original Poster:

666 posts

192 months

Tuesday 19th July 2011
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Yep... air coming back up into the air filter housing .. no hoses removed at any time..

H6CJF

Original Poster:

666 posts

192 months

Wednesday 20th July 2011
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Morning chaps

Seagrey, Sprinter - thanks for the suggestion. However, I would be surprised if it were the breather as a) it was only replaced less than 12 months / 10,000 miles ago & b) This is a 'sudden' failure.

Having pondered on this over night I'm thinking about either a MAP problem or possibly vac hose? It seems that what is happening is the 'wastegate' is actuating too early? From looking at other threads, the fail safe mode (if there is no vacuum)is to remain 'open' - ie recirculating boost pressure back to the inlet side of the turbo.

I shall do some hose tracing later but in the meantime any other input welcome..... Got to get the lad back on the road... I want MY car back mad

H6CJF

Original Poster:

666 posts

192 months

Wednesday 20th July 2011
quotequote all
Mr2Mike said:
Doesn't the 330D have a variable geometry turbo i.e. no wastegate? Have you checked the EGR valve?
Yes it does - hence my 'wastegate' as it does perform the same function and is more widely known term. As I undertand it the vane position is determined by vacuum - hence my thoughts turning in that direction.

Powerstroke, thanks for that but it is definately 'boost' that's getting back rather than exhaust

I have meetings this morning so will get round to having another look after lunch and reprt back

Cheers all

Chris

H6CJF

Original Poster:

666 posts

192 months

Wednesday 20th July 2011
quotequote all
powerstroke said:
I think the turbo is the least likely cause
I tend to agree. I was under the impression that although there is no wastegate / dump valve, there was still a recirculation device of some sort to recycle excess boost back into the inlet side of the turbo. If I'm wrong then fair enough.

So, I think its a case of starting at the beginning (wherever that is lol) and working through logically, cleaning checking etc

I just don't understand why there is so much noise coming up through the air intake 'from' the turbo once rpm reaches around 2500 - 3000. Anyway, as I say, I will take a logical step by step approach and see where we end up

Thanks again

H6CJF

Original Poster:

666 posts

192 months

Wednesday 20th July 2011
quotequote all
Update:

Right - still no better but here's what I've done so far:

- Cleaned out the EGR valve and checked that it moves!
- Cleaned the MAP sensor
- Cleaned out the crankcase breather
- Checked the turbo actuator arm moves ok
- Checked all vac hoses and electrical connectors are on tight


With the air filter removed, when I rev it, foot down - black smoke comes out of the MAF sensor, (yes I know its supposedly drawing air in at that point but as I hit the pedal and it gets to around 1700/2000rpm there is definately black smoke coming out of the MAF itself. Foot off as it reaches c3000 & I get the 'dump valve' noise coming back up the intake. I am beginning to suspect turbo internal seals or something - dunno.. I'm a bit stumped with this one. Oh, and plus it is running like a bag of spanners, hesitating, running on five under load ... you name it.

Even with a duff injector it was running better than this!

Anybody want a 330d? rage

H6CJF

Original Poster:

666 posts

192 months

Wednesday 20th July 2011
quotequote all
Mr2Mike said:
Could it have swallowed a swirl flap? That could explain the running on 5 problem, and a slightly bent inlet valve could cause any combustion products to be pushed into the inlet.
No swirl flaps fitted... I made sure of that when I swapped the manifold a few weeks ago.

Turbo isnt making any odd noises so I am a bit flummoxed. I'm going to pop it over to a local Indy tomorrow to see if he has any ideas.

To think, I was a fully qualified diesel tech in 1972.... it's all changed a bit since then lol!

H6CJF

Original Poster:

666 posts

192 months

Tuesday 7th April 2015
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Still here!

Not going to be much help though I'm afraid...
Never did get it sorted. The solution we reached was to stick it on EBay as a non runner

Good luck though and let us know how you get on