# diesel engine buffs, whats this?



## seanoo (Mar 31, 2007)

hi all , do any of you knowledgeable diesel buffs out there know what the part is below? the engine is my 2007 sprinter 316 5 cyl . the part is attached to the bottom of the airbox and has a rubber tube going to the turbo . i took as good a photo as i can but it is in a really hard place to get at. when i turn the engine off this little thing makes a sort of buzzing sound for about 15 seconds , not too loud but i had the bonnet up at the time and noticed it. doesnt seem to make any difference to engine while driving and no lights on the dash. any ideas ? regards sean


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## Easyriders (May 16, 2011)

I'm very far from a buff, but I do know that on diesel engines you are supposed to wait a few seconds between turning on and firing up the engine, presumably so some sort of electrical connection warms up the diesel vapours so the engine can fire without flooding.

So it might have something to do with that? (Or I might be totally wrong!) linda


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## cabby (May 14, 2005)

Are you sure that it actually enters the turbo unit, or is there another bit on the turbo that the hose goes into. cannot really see on those photo's.

cabby


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## seanoo (Mar 31, 2007)

the noise is coming from the boost control sensor under the airbox. doesnt seem to affect performance at the moment. and just makes a noise after turning off the engine


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## listerdiesel (Aug 3, 2012)

Looks like a purge valve.

Peter


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## Carl_n_Flo (May 10, 2005)

No need to fret on the noise - ours has done it since new with absolutely NO problems....

My diesel Golf does the same....

CT 8)


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## Tricky2 (Feb 10, 2008)

It looks like a vacuum pressure transducer! Had to have one replaced last year due to loss of power. It apparently regulates the amount of pressure required to the turbo, so I was told.
Rick


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## blondy (Aug 23, 2007)

*Turbo*

It could be one of the pipes that control the waste gate, the bit that controls the turbo pressure so it doesn't over boost,


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## seanoo (Mar 31, 2007)

cheers guys, i have found a very small pinhole in a vacuum pipe under the airbox and when i turn off the engine the noise is it pulling in a little bit of air. doesnt seem to affect performance at the moment so will get it fixed asap. cheers again


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