850 1996 Screeching

gradstudentanna · Post by **gradstudentanna** » 05 Oct 2009, 20:41

Hello,
My 1996 Volvo 850 is making an awful screeching noise when I start the car. Over the summer, it made the screeching noise frequently (while the car was driving) when I was driving in the mountains, running the air conditioner, or on long road trips. We seemed to have to fill up the coolant a lot more frequently than usual -- once every three months instead of once every 6 months to a year or so. Funny enough, after mountain driving, running the air conditioner, or long road trips, my car often thought I was stealing it -- I would put my key in the driver's side lock, turn it, see the car unlock, but wouldn't be able to unlock the other doors this way. The indoor lights would not turn on, and when I opened the door, the car alarm went off. If I opened the passenger side door, all doors unlocked fine.

My dad just replaced the serpentine belt this last weekend. He changed the oil, filled it up with coolant, took the door apart to clean the contacts, filled the power steering fluid, and filled the brake fluid. He also checked the battery. The car seems to be running better -- but it is still making the noise when I start it cold.

It's a high-pitched squeal/screech that happens right when I put the car from park into drive. It only happens when the car is cold (haven't tried mountain driving, long road trips, or A/C yet). It sounds like something revs up, stays on for a minute or so, and then winds down. So far, the noise hasn't happened while driving, and it hasn't happened when the car is warm. Any ideas what it could be? Dad and I are stumped!

Thanks,
Anna

Post by **Ozark Lee** » 05 Oct 2009, 21:54

Welcome to MVS,

You have a number of things going on that kinda conflict. The coolant loss makes me suspicious of a failing water pump. That is something not to be ignored, if it totally fails you are looking at a new engine as the timing belt will either break or fall off when the water pump gives up the ghost.

The additional noise when the A/C is on and the problems with the immobilizer, on the other hand, point to a problem with the serpentine belt tensioner or a bearing going bad on one of the items on the serpentine belt path.

If it were me I would remove the serpentine belt and start the engine. The dashboard will light up like a Christmas tree but no other bad things will come about as a result of that. If the noise goes away then you are looking at something on the serpentine belt path. You can use a long screwdriver as a "mechanics stethoscope" to narrow down the problem component after the serpentine belt is put back on. The serpentine belt tensioner should keep the belt very tight, the serpentine belt shouldn't flop around at all with the engine running.

Keep in mind that there are two different serpentine belt routings for the car and the routing on the label under the hood is likely not correct if you have the longer serpentine belt. The longer one is the "updated" routing and that belt would likely be the part that you were sold.

If the noise persists after the serpentine belt is removed park the car and don't drive it until it is fixed, that indicates a problem in the timing belt system.

...Lee

Post by **jtp** » 06 Oct 2009, 12:56

gradstudentanna wrote:
It's a high-pitched squeal/screech that happens right when I put the car from park into drive. It only happens when the car is cold (haven't tried mountain driving, long road trips, or A/C yet). It sounds like something revs up, stays on for a minute or so, and then winds down. So far, the noise hasn't happened while driving, and it hasn't happened when the car is warm. Any ideas what it could be? Dad and I are stumped!

My car does that and I think it's the radiator fan kicking on. Some miscommunication going on that the car needs to be cooled down even though the problem is actually that you're not letting the car warm up long enough.

Test this: if it's what I think it is then the "high pitched squeal/screetch"'s length will be inversely proportioned to the amount of time you let the car warm up, keep it itdling in park for 30 secs shorter squeal, idle for 1 min. and little to no squeal, etc. ....

It is weird, but if you let the car warm up it doesn't happen so I just haven't worried about it. If it's happening when driving uphill frequently or with the a/c on then it needs to happen at those times, those can be good times for your engine to cool itself down. I wouldn't bet it has anything to do with your car's electrical oddities, those are just part of the joy of owning a volvo

gradstudentanna · Post by **gradstudentanna** » 10 Feb 2010, 23:48

So sorry I haven't gotten back to this! I took it to the mechanic, and he diagnosed it as a secondary air pump failure. He said that he'd heard that part make a ton of noise, but never one like that!