Passat whissling a tune to me!

[Jon A]

Hi everyone,

for a while now I've been parking up after a drive and hearing a whissle for the engine bay, sounds like high pressure gas escaping. I havent thought much about it for a while, but its been getting more and more random, going higher and lower pitch like its playing a tune! I thought it may be the ac system at first, but its getting progressively worse.... Dont think its gonna blow up or anything, just curious to what it could be.

Any ideas.....?

Cheers
Jon

[dangel]

NA or turbo car?

[Jon A]

NA or turbo car?

Sorry, should have stated, its a TDi (110 re mapped to 142).

[dangel]

Could well be a leaking air pipe - get a mate to stand to the SIDE OF THE CAR (not in front) with the bonnet up and put it on the handbrake. Then bring it to biting point and give it a little gas - this is to load the engine which will cause the turbo to boost (it won't when the engine is just free revving). If it's a air leak your should hear more clearly where it is coming from as a result. Take great care not to overdo it and shoot off down the road (don't do it facing the garage either lol).

I've had a problem where the pipe leading to the intercooler came loose and needed clipping back on and it sounded the same as you describe. You can also get collapsed pipes etc or just plain worn/leaking ones.

[Jon A]

Nice one, cheers dangel, I'll give it a go.

Would it still be doing that when the engine isnt running though? Excess pressure or something?

Jon

[dangel]

Ah sorry - engine off? No shouldn't be that then

Might be as well to get on a VAG forum an find some tdi110 owners with experience. Best of luck matey

[Gr44]

Air conditioning gas or something?

Don't know much about it but it's probably the only other heavily compressed thing in the car.

Coolant? Make sure the coolant is properly sealed up, that will hizz if it's leaking. Though I wouldn't have thought loudly enough to hear it over the engine..

[Jon A]

I'll see if I can get some kind of a recording of it and post it, difficult to describe it in words....

Thanks for the suggestions guys.

[dave87]

Are the brakes on the Passat servo'd?

IF so may be the vacuum pump on that. It began to fail on Mum's Volvo v70, and made a sort of hissing/whissling sound audible in the cabin.