1998 V70 R AWD Whistle/whine on acceleration- need opinions

[craywm]

I was able to use my mechanics stethiscope and rev the engine in the garage to hear the whine from the turbo. I could not hear it on the compressor body, but once I put the tip of the scope on the exhaust manifold, I could hear it clear as day. I'm thinking the exhaust side bearing in my CHRA is bad. Another option I am considering is that the CHRA/compressor body assembly is not fully inserted into the exhaust housing side. There is a heat shield that could rotate with the turbine wheel if it were not fully secured. I had a heck of a hard time getting the turbo the fit back into the exaust side housing. I thought it was fully seated but I guess its possible its not.

I still plan to order a new CHRA (after evaluating a little more). I was wondering if anyone knew if my Exhaust side turbine housing could cause the turbo CHRA to go bad? I don't want to get a new CHRA and have it fail in 70 miles too. Does anyone know what could cause a turbo to go bad that quickly? Besides low lubrication and cooling (which I'm fairly certain is fine)?

[johanc70]

@craywm Did you manage to locate what caused the whining noise? I have the same whining in my 850R and i have tried another turbo but noise is still there.

Thanks

[scot850]

One point that you should check is that your exhaust manifold and down pipes have not cracked. This is problem that does happen, and when you disturb the rusty old originals something may have broken. It may not be the turbo at all.

Neil.

[johanc70]

Thanks,
I did change the exhaust manifold and the down pipe looked OK, unless it's got a crack in the flex part.
The search continues.

Cheers
Johan

[craywm]

I decided the noise I heard was just normal turbo operation. After replacing the turbo with a new unit. The noise came back but never got as loud as the first time. .