Need help!

My 1996 volvo 850 turbo with 105,000 miles has begun to make a squeeling noise from somewhere under the engine compartment only when I accelerate first thing in the morning when the engine is cold. Once the engine is warmed up after about 4 minutes, the car no longer makes the noise. I am assuming it is a bearing wearing out somewhere, but have not been able to figure out which one it might be. I have changed all of the belts at the recommended timing intervals, but have not ruled them out either. Any help diagnosing this would be much appreciated.

Thanks
Steve

My 850 with 137,700 miles has been doing this since I bought it at 60K. Like other posts have said if it is the air pump it seems to be a harmless quirk.

Thanks John! I'm feeling much better after your feedback and others as well as the info I've found in the archives.
Steve

Unexplained loud squealing could also be the Oscillation Dampener. It is a 2-piece wheel bolted to the crank and drives the serpentine belt. I had the same problem you described.
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Daniel - '93 850 GLT, 137,000 mi

Thanks Daniel!
If this turns out to be the source of the noise, should I be concerned about changing out the dampener immediately?

Steve

That I don't know. I would imagine to do it as soon as posssible, though mine squealed for about 6 months getting worse and worse before I gave up and took it to a mechanic. Also, my mechanic said it could have been the tensioner pulley for the serpentine belt or the pulley for the timing belt, either can be critical. If the serpentine breaks it could snake under the timing belt cover and break the timing belt, meaning a valve job. Sorry I didn't mention that before.
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Daniel - '93 850 GLT, 137,000 mi

Was your noise a constant noise? or did it go away after the car warmed up?

When it started it was just a bit at startup. Over time it would continue longer, 10 seconds or so and then quit. Then it would squeal off and on with the AC on, or any load on the electrical system while idling and then quit with more RPM. After a while just rolling down the window down and up would cause a squeal or if accelerating really hard, there would be a little squeal as the transmission shifted. Eventually it would squeal the entire time the AC was on. After serpentine belt changes, belt dressings with no change I found an indie volvo mechanic and it was fixed.
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Daniel - '93 850 GLT, 137,000 mi

another pic
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Daniel - '93 850 GLT, 137,000 mi

Common problem. It's probably the air pump. Do a search here and on Volvospeed for more info. If you can live with the sound, it's practically harmless, though.

Gerald C

Thanks Gerald! I will look it up in the archives. The noise lasts for such as short duration that I will probably just live with it unless it gets worse. I feel much better now.

Steve

Just so you don't get too comfortable, the sound might also be the belt tensioner. If it's the air pump, it will only last exactly 2 min after cold start, and the sound will come from the battery area (underneath it actually).

If it is the air pump, and no codes are being set (i.e., no check-engine light), then leave it alone.