MielsOnWheels

I just noticed a bit of belt squealing. I have not heard this until the weather recently turned cold. I had the car out last weekend on a 200 mile fun run, probably mid-50's and never heard it. In the last week as the weather has turned cold, I hear it with moderate revs on start up and when in neutral as I shift into 1st or 2nd gear. It seems to go away when the car is warmed up.

I looked at the 60k service bill that was done prior to me buying the car and I didn't see that they had been replaced.

A/C Belt - unmarked, deflects about 1/2 an inch

Front Belt - Branded "Conti", deflects about 1/2 inch

Rear Belt - unmarked, very little deflection, maybe 1/4 inch?

Just wondering if the squealing is something others have experienced when the weather turns colder? This is my first winter with the car.

Could these be the original belts?

Is the best way to eliminate it just to replace them?

I'm not handy and I'd have my mechanic do whatever fix is needed, so I'm just trying to understand what the issue/fix could be...

993/907

Cold has never affected the belts on my '95; always quiet.
Gordo

kjr914

60k service should have belts in it IIRC... There is a little wear from the fan belt sensor wheel, so that means they've been on there a few miles, probably 5-10kmiles minimum.

Rule #1 around here seems to be use only Porsche belts (these are not. The Porsche fan and alternator belts will say Porsche, the AC belts I've seen say Conti in green). Some of the non-Porsche belts are just slightly different in size and have all kinds of weird effects.

The 1/2" deflection might be a little much, but very subjective since how hard you press really determines this. My guess is your alternator belt (yellow Conti in the picture), since it is deflecting 1/2" and drives a heavier load (fan is pretty light in comparison to spinning the alternator). AC belt should have very little load if the AC is off (is it? Are you running defrost?) and really shouldn't slip then...you can turn the AC/defrost on/off to check if its that belt.

You could experiment with removing a shim to tighten the belts, but once you are in there, its just as easy to install new belts as well.... Takes less than an hour if you've done it before, budget 2hrs if you've never done it. (estimates assuming you own a magnetic pickup device to get those dropped nuts/shims/washers. Much longer if you do not have one of these....)
http://www.pcarworkshop.com/index.php/993_-_Belts

ShdwFx

I had a slight squeal with my belts and it turned out to be the belt sensor roller. I sprayed a bit of Triflo on the roller and the squeal hasn't come back since. You might try that before replacing the belts.

P-daddy

+1 on Porsche belts

Quadcammer

hard to tell, could you post a bigger picture.

MielsOnWheels

Keith,

Thanks very much for the info, very helpful!

Update - My bad,actually the belts do have markings on them. The A/C belt is Porsche-branded (green lettering) and the fan belt is Dayco-branded. As noted above, the alternator belt is Conti-branded.

As a matter of fact, I did use the defroster last night and that's when I heard the squealing. I drove the car today and turned it off, no squealing.

Thinking the A/C belt might be the culprit and it may likely be original?

I did buy replacement fan and alternator belts when I bought the car in April. They are Porsche part#s but Dayco branded. I think I might have gotten them from Pelican?

MielsOnWheels

Quad,
Did you choose that screen name to reflect the fact that your mouth is 4X bigger than everyone elses?

I, and many others, come to this forum for technical advice, hence my post. Perhaps I can suggest to you a photography forum where you can find lots of other professional photogs like yourself. This way, when you make a smarmy comment on a posted pic, someone might care and not just think you’re an *** like I do.

So do me and everyone else a favor and keep your mouth shut unless you have something valuable to add to the conversation.

Magdaddy

the belt tension sensor was my squeeling culprit. A simgle bolt...5 or 6mm IIRC holds it in place. Unplug-remove, soak overnight with some sort of penatrant/lubricant. I'm a tri-flow fan myself.

If you have no records showing that ALL three belts have been changed within the last 30K miles, get them done now.

It's a fairly straight forward task, you do need a couple of special tools to accomplish though.

Good Luck

Quadcammer

actually chief, my mouth is very proportional, thanks.

now about your little problem. You have a squeak. Its coming from the belts.

There are only 2 things that can produce this problem.

The belt or the belt sensor.

So, use a zip tie to retract the sensor. If it still squeaks, its most likely the belts, which, as you've obviously found out, are extremely cheap.

Now, given that you've tested the tension, not with the proper gauge, but with a deflection test, perhaps you just need to replace the belts.

This is about as good as you're going to get for an internet diagnosis. Why not bring the car to your mechanic and have him diagnose it.

As for the rest of your comments, I don't think terribly highly of you either.

MielsOnWheels

See, now was that so difficult? If you had posted that helpful information in the first place, then I would have thanked you for the help instead of laying you out on the forum.

So, thank you anyway and I hope you learned a lesson today. This forum will be much better if you think before you open your mouth next time.

TRINITONY

Those belts are easy to change and fairly cheap. Why not see if any of the dorki guys are local to you, and give you a hand changing them.

kjr914

Its not clear if you turned on/off the AC and it directly affected the squeal, since you reference testing it on 2 separate days. While its squealing, turn on/off the AC....this will directly dis/prove causality. However, you can easily tighten the AC belt (4 bolts on the AC compressor loosened and tighten the adjuster, re-tighten the compressor bolts) as a first attempt to clear the issue before belt replacement.

The suggestion of a drop of lube on the fan sensor bearing is also a good one. Probably not your issue, but if it prolongs the failure of the sensor, all the better.

Dayco belts...they could be the OEM. Real Porsche belts say "Porsche" on them in white, along with the part number.

IXLR8

And a 3rd; the fan hub bearing.

I'd tie back the cooling fan belt sensor as already suggested.

Then I'd remove one belt at a time from the AC to the cooling fan to see which one causes the squeal. If the engine is cool, there is no issue running it for 15 or 30 seconds without the fan spinning .

If the cooling fan belt is still in place, which is the last one, then it might be the belt or the fan hub bearing.

IXLR8

And my alternator belt is Dayco branded as can be seen below. All three of the original belts on my 993 were Dayco branded - Made in Italy.