924Board.org

[AndyR]

My car has been sporadically having a problem where it would produce an awful squeal, somewhat similar to brakes that need to be replaced. It is coming from the engine bay. I've noticed a couple things about it:
-It only begins when I turn on the ignition, never while I'm driving
-Happens while in gear or neutral
-It doesn't seem to matter how long the car has been off, it happens when I start the car in the morning, if it has been sitting an hour sometime during the day, and even when I stalled it once and it was off for the span of two seconds, tops.
-It doesn't seem to be temperature dependent, see above examples
-After an amount of time, the squeeling would go completely silent without any warning and stay that way for the rest of the trip. It used to only last for just the amount of time it takes to roll out of the driveway (or a little longer), but on a recent drive it kept on going for maybe 40 minutes.
-The loudness was directly linked to engine revs, 1k is somewhat quiet still audible, 3k much louder than the engine, probably very noticeable to anyone on the street.
-On the drive where it persisted for nearly an hour, the squeal started very loud (in a parking garage too, enough to make your ears bleed) but after a while the tone gradually got lower.
-After that drive it changed somewhat, the noise doesn't get much louder if the car revs up, but it doesn't go silent quickly or at all while driving since.

At first I ignored it because like I said, it would last no more than half a minute and then the car would act perfectly normal. Ever since the squealing started persisting, I've been very hesitant to take the car long distances or anywhere I didn't have to go. Aside from that noise it still performs like usual, but I figure that it could now be just a matter of time before something breaks in a bad way. Does this sound familiar to anyone? Does this sound like it could be a serious problem waiting to happen?
_________________
-White 1987 Porsche 924S (Hawaii)

-Black 2000 Audi A4 (Mainland)

[gohim]

Sounds like you have a bad belt, or a bad bearing in a pulley.

When was the was time that you had the Front of Engine Service performed (replace water pump and belts), and the rollers and pulleys replaced? This should be done every 3 years or 30k miles to avoid sudden failure of the timing or balance shaft belts.

You should also have the accessory drive belts checked, and the accessories (power steering pump, alternator) checked for defective bearings.

[Paul]

I agree, but I would start by checking the alternator/air conditioning belt.

It could be the alternator pulley stalling as it is trying to recharge the battery which was drawn down from starting the car.
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

[AndyR]

I'll be sure to check the belts, but I'm going to wait until I get a Haynes manual on Monday before taking anything apart.
I have no idea what kind of maintenance the car has had, but I'm guessing that it has not been serviced regularly. I've been considering taking the car to the dealer to get everything checked out because of that.
_________________
-White 1987 Porsche 924S (Hawaii)

-Black 2000 Audi A4 (Mainland)

[Paul]

I'd stop driving it, or you may suffer the expense of a blown motor.
_________________
White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

[Hoboceratops]

Get a Haynes manual, tension up the accessories belts. It's really, really easy and will just take a few minutes. Squealing like that is generally associated with a loose ac/alt belt from what I've seen, with just about any car at all.

Still need to worry about the front of engine service though, this is just to deal with the noise.
_________________
1987 924S: Very much in love with it, even if it's all finnicky

[MrMoMo]

Last time I had that happen I checked the main belt tension, I could spin the alternator by hand without the belt turning. I re-tensioned the belt and everything has been good since then.
_________________
Bruce

-------------------------
'87 924S (project 937)
'87 924S parts car
'87 924S parts car
-Strewn amongst the other vehicular mass engulfing my property!

[AndyR]

I took a look and yeah, I'm not taking the car anywhere. The outside 'rib' on the belt in front is frayed and coming off.
_________________
-White 1987 Porsche 924S (Hawaii)

-Black 2000 Audi A4 (Mainland)

[AndyR]

Quick Question: Can the car run without the drivebelt? If it turns the alternator then that means that the battery won't be charged while the car is running, which means that the car's range would be limited to how long the battery goes before being depleted, correct?
_________________
-White 1987 Porsche 924S (Hawaii)

-Black 2000 Audi A4 (Mainland)

[gohim]

The power steering will not work either. If you try to drive the car that way, muscling the steering, power steering fluid will get dumped all over the street as it overflows from the power steering reservoir.

If the accessory belt is bad, why don't you replace it? Then you can drive the car directly to your mechanic to have the balance shaft and timing belts replaced. The timing belt and balance shaft belts are the ones that will cost you thousands of $$$ if either of them jumps a tooth or breaks.

[AndyR]

I *was* replacing the accessory belt when I discovered that a bolt was broken. It's the front mounting bolt for the air-conditioning compressor, there is supposed to be a rear one too but it wasn't there on my car. the bottom half of the bolt is still threaded into the a/c compressor. I don't think I can put the new belt on and drive to a mechanic because the a/c would not be held securely enough with the accessory belt running. On an aside, I'm not worried about the power steering because it is already inoperative (which actually isn't that bad but that's beside the point). I could remove the compressor and take that into a shop, but I'm not sure if the a/c is discharged. The a/c doesn't blow cold when on, is that enough to go on?

[edit] nevermind, a/c's discharged, compressor's pulled out, it ought to be easy from here[/edit]
_________________
-White 1987 Porsche 924S (Hawaii)

-Black 2000 Audi A4 (Mainland)

[bcblase]

If you pull the A/C compressor and go with the shorter belt for the alt. only, do you really need the "A/C Delete Plate: that some places sell?

i.e. 944online.com sells the plate and short belt as a kit for $179.
_________________
1987 Porsche 924S - track toy
1986 Mercedes 190E 2.3-16v - autocross
2007 F-150 5.4L Lariat Supercrew - tow beast
1994 Volvo 850 Race Wagon - 24 Hours of Lemons Car
2001 BMW 325xi - daily driver

[AndyR]

Oh I'm only pulling out the compressor to get the rest of that bolt drilled out so I can put it back in securely. It gets hotter than hell in Hawaii and I'm going to get the air-conditioning working before next summer!
Since the belt tension gets adjusted by moving the a/c compressor, I'd assume that you have to replace it with something if you want to take it out. I can't see from the image how the delete plate you mentioned is supposed to work though (shouldn't it have a wheel the belt goes around?), so your guess is as good as mine
_________________
-White 1987 Porsche 924S (Hawaii)

-Black 2000 Audi A4 (Mainland)