For the last week or so, I've been getting this strange screeching/groaning sound from the engine area of my 1995 Volvo 850 T-5R. When I first heard the sound, it only lasted for a few seconds; now, the sound lasts for a minute or two, until the engine warms up a bit. For the music heads out there, it sounds like Sonic Youth or The Jesus and Mary Chain is playing in my engine.

The car has about 158k on it and the timing belt was changed at 135k. The temperatures here have been in the 80s and 90s, so according to what I've researched, this doesn't seem to be the air pump "ghost" that others have experienced when starting their 850s in cold weather. From what I've deduced from a Brickboard search, it could be the idler pulley, serpentine belt, idler bearing, water pump, air pump, or in fact the spirit of old man Volvo?

I recorded a 30 second clip of the sound today and uploaded it here:

http://www.youtube.com/watch?v=-9MvAjVXb7s

Any suggestions, advice, or personal experiences before I bring this in to the stealership would be greatly welcome. Thanks.

That certainly sounds like one of the idler pulleys. I use an old round stick as a stethoscope, one end held to the bone just infront of my ear, and the other end on where I think the noise could be coming from. It works great, BUT whatch out for the belts and other spinning parts!!

You may have to take off the timing belt cover and check the other spinning parts, just a single 12mm bolt is holding it on.

Klaus
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I still miss my 164 and my 854T. Just driving a V70R :)

Thanks to those who responded.

I will see if I can pick out the sound. I did notice that the sound is still there (just much less noticeable) when the engine is warm. The sound does not seem to vary with engine RPM.

I think I may have figured out what caused the problem, though. I had the A/C recharged last summer (there was no refrigerant in it whatsoever), but during the last month and a half the compressor has been clicking on and off at an increasing rate--even when the A/C is set to Off! I imagine that this has been a pretty significant strain on the serp. belt and/or pulleys. I'll create another thread about this issue--hopefully someone can shine some light on why my A/C seems to be running constantly. This A/C constantly on problem does seem to occur only on highway driving, which is even more perplexing to me.

The AC will cycle right after engine start up, part of the checking process. If you have the vent set on defrost, the AC will come on even if you have switched it off.
It does make a difference if you have electronic climate control or manual. But it sounds like the system is low on refridgerant.

Klaus
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I still miss my 164 and my 854T. Just driving a V70R :)

It is an electronic climate control system. I do leave it on defrost most of the time, with the temp set low in the summertime, so I will see if it still cycles on and off with the AC set to OFF and the Vent set to DASH or FLOOR. Thanks for the tip.

You need to get a stethescope or a small pipe and narrow down where the noise is coming from by listening and moving the pipe about the engine bay.
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Tek

You need to start by narrowing this down to which belt is generating the noise, remove the serpentine belt and start it up. If the noise is still present then you have a timing belt issue, if not then something in the serpentine belt circuit is shot. If this is the case then while you still have the serp off give all of the pullies a few spins apiece to see if it can be narrowed down this way. If not then you need to put the belt back on, fire it up, and then carefully use a mechanic's stethoscope to try and locate the noise. If the noise turns out to be in the timing belt circuit then I would recommend the shotgun approach, go in there and replace the idler and tensioner pullies, if the tensioner shows signs of leakage then replace that sucker too. I guess it is possible that the water pump could be making the noise but it would be unsual and not consistent with how your noise presents itself, typical bad water pump bearing noises do not come and go like yours does. Most of the bearing noises that I have had that only duplicate on a cold engine for a minute or two when first started have been timing belt tensioner or idler pullies.

Mark