# whistling noise on a 320d



## talkdtalk (17 Feb 2009)

Hi, 
On my 02 320d there is a whistling noise when I let off the accelerator. I was told it is not a problem with the turbo, 
does anybody know what it might be and how I might repair?


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## Nissman (17 Feb 2009)

Has it only started happening or have you just become aware of it now?
Or has it become louder than normal?
As its turbo its normal but if unusually loud there could be an underlying problem.


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## talkdtalk (17 Feb 2009)

Recently become aware of it and it seemed to get louder and then stay at that level. 

Didn't know it was normal - does this happen on all turbos?


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## mathepac (17 Feb 2009)

It could be the turbo, EGR plumbing, faulty dump-valve or a loose inter-cooler hose-clamp. Any sign of it losing power or making smoke under boost?

The turbos have been known to be fragile on these cars.


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## talkdtalk (17 Feb 2009)

No I don't think it is losing power, 
Don't think it is smokey but will try check later.

What is the best way to check if it is any of the things u mention? 
Afraid the main dealers will just say "we will start with changing the turbo and take it from there" - or am I being unfair will they be able to diagnose a specific problem? 
reluctant enough with a 02 to go main dealer


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## mathepac (17 Feb 2009)

Plumbing is easy to check - 


 on the outlet side, follow the run of pipes hoses clamps and connectors from the exhaust manifold to the turbo (I think the dump-valve is integral to the turbo) and EGR
 on the inlet side follow the run of pipes hoses clamps and connectors from the air-box to the turbo via the inter-cooler to the inlet manifold.
  Check all the hose-clamps / connectors for tightness (Do NOT over-tighten)
Check the oil-feed pipe to the turbo and the return for leaks / drips
Check for oil in the inter-cooler and piping (there will be some if its a Euro IV emissions engine; if its a Euro III engine it probably won't have an EGR, therefore less chance of oil in the inter-cooler and piping)

I suspect you will only hear the whistle when the engine is under load so revving the nuts off it while stationary probably won't help to pin-point the problem

Do all your checks with the engine cold as you risk injury / burns with the engine hot or running. 

If all the above checks out then I'm afraid you need a beemer tech (which I'm not ) and it may be the turbo (probably bearings).


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## kceire (17 Feb 2009)

talkdtalk said:


> No I don't think it is losing power,
> Don't think it is smokey but will try check later.
> 
> What is the best way to check if it is any of the things u mention?
> ...


 
bring it to AC Cars near the SCR.
these cars need some sort of turbo filter or similar replaced quite regulary, cant think of the name of it but any BMW nut will fill you in.

its happening to a few people at the moment and very common on certain 320d's of that era.

http://www.bmw-driver.net/forum/showthread.php?t=7711

http://www.bmw-driver.net/forum/showthread.php?t=7679

http://www.boards.ie/vbulletin/showthread.php?t=2055239921

should be a good bit of info in those threads for you.


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## rev87 (18 Feb 2009)

kceire said:


> these cars need some sort of turbo filter or similar replaced quite regulary, cant think of the name of it but any BMW nut will fill you in.


 
Crankcase breather valve. About €50 or so


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## talkdtalk (18 Feb 2009)

Thanks a mill Mathepac for the very helpful detailed advice, will hopefully try check all that tonight. 
Yes, you are 100% correct, no noise when the car is stationery, only when moving wehen I let off the accelerator. 

Thanks for the links kceire --> hoping/thinking its not the turbo.


Rev 87 do you think a crankcase breather valve should fix the problem as described? Are they hard to fit?


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## mathepac (18 Feb 2009)

talkdtalk said:


> ... Rev 87 do you think a crankcase breather valve should fix the problem as described? Are they hard to fit?


Spot on I, forgot that one from my list.  Its worth a shot.

Its a shortish tube that runs from the top of the rocker-cover back into the air pipes with a clip at either end. A 1 minute job to change. They can get clogged with oil and gunk.


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