Turbo noise diagnosis?
 

I used to be able to hear my turbo whistle ever since I bought the car.

Seems now the whistle has been replaced by a noise similiar to when one uses the "canned air" for cleaning computer keyboards.

The car runs and drives fine. I did a valve adjustment 2 weeks ago.

This noise only happens as the turbo spools up, and abates when you reach cruising speed. At 70 mph, I can hear it just a bit, it dissappears when I let off the accelerator, but increases when I accelerate, even at 70. I tried listenening with the window down, but nothing abnormal. I can only really hear it with the windows closed. It appear to be coming from the passenger side as I would expect.

Any ideas on what to check? I wonder if the intake gasket is leaking...

Thanks!

My Jetta TDI whistles as it spools up then "hisses" when the wastegate opens at full boost. It sounds like yours is hissing the whole time during acceleration, eh? And you have normal boost, it sounds like? Strange...

You probably have a leak in the manifold side. I just had/fixed the same problem with my w126. Turns out it was one of the large rubber o-rings between the compressor on the turbo and the cross-over tube.

They can sound really weird...the guy at my turbo shop here said he has even seen them whistle like a siren on an ambulance.

I do not think the OM617 has a crossover tube. Please elaborate, as I have been wrong many times before.

The seals on the U-tube have been replaced, as has the air filter, etc a few weeks ago. This just started on Tuesday.

Also the turbo shaft spins freely, and there is no side to side play, but you can just feel end to end play.

Yes, it is strange.

Thanks!

Take some soapy water to the intake and exhaust gaskets and see if they bubble under boost load.

How can you get it under boost load with the car in park?

Clearly not in park. Per FSM put your foot on brake and put your other foot on accel. I know scary but its in the FSM.

Ah, I see...well that is what a helper is for...

Noise problem cured
 

The noise turned out to be caused by the EGR. The bolts had worked loose, and exhaust was pouring into the engine compartment, under acceleration.

Well, time for a blocking kit. I just need to get dimensions and I can get it made for free from stainless steel.

The barter system works great, I think. I trade computer repair work for metal shop work.

Thats a nice setup. (the bartering)

The word on the street is that a quarter fits in there just right with lots of hitemp RVT.

Winmutt, does the quarter go in the clamp on the exhaust manifold outlet?

Intake manifold, remove bolts, pull off the EGR, apply a decent amount of hitemp RVT, insert quarter, more RVT bolt her down.

hmm, I haven't heard of that one. I just cut the block plates out of a thin piece of tin, then new gaskets out of the roll you buy at autozone. Takes about 20 min total.

Just for the record, I know the 617 doesn't have a cross-over bar, that was the problem I had with my 603.