Belt Squeal 88 Carrera and strange explanation....

Geneman · Geneman's Garage

I have experienced intermittent belt squeal including burning smell in cockpit, bit of smoke etc. For about a year No sound at idle but rapidly escalates at Increased rpm in neutral....obvious belt problem to me. no problem with AC clutch etc.

Mechanic replaced, tightened belt about 1.5 months ago. It sat that long without being driven then upon startup squealed again with all the symptoms!!

Upon return the mechanic ( well respected P guy around here) told me that if battery was significantly discharged (from sitting around/non-use) upon startup, the added strain produced by the alternator could cause the belt to squeal.

I find this very hard to believe...that added torque/mechanical strain to the alternator due to charging load could affect belt function...IE a 210 hp engine could be affected by the rather small mechanical load produced by an alternator.

Am i crazy or what? Is he treating me like an idiot? if so.. what is this PhD worth??!!

equipment : stock 88 carrera (1 owner garage queen) , 72K, no engine mods, older autothority chip

Sincere Thanks to all Pelicans this is a wonderful community!!

kidrock · 07-20-2010, 07:03 AM

You don't state where you're from, but maybe the belt is kinda dry and not broken in...get some belt dressing from the local auto store, and make sure the belt has about 1/4" tension after tightening...probably the simplest maintenance to be performed on our cars.

There's also the chance that you may not be driving the car enough...for some reason, simple things tend to flare up on these cars if not driven hard and often. That's how they were built.

E Sully · E Sully's Garage

You want to make sure all the shims are installed on the pulley wheel. If any were left out it may cause a problem. Low battery will not increase the alternator load on the belt.
The belt might stretch a bit and need to be retightened after initial use. As kidrock said, check for about 1/4" of play at middle of belt.

rusnak · 07-20-2010, 07:41 AM

Geneman, you need to learn to change the belt yourself. It's really easy, look for threads with pictures (I recently contributed to one, and there is at least one more recent one). Test-spin the fan to see if it's hitting the fan shroud. Make sure that the belt is either a Continental Rubber belt, or a Porsche factory belt. Count the shims, and make sure there are 6 as already suggested.

Geneman · Geneman's Garage

Thanks to all for replys I am in Philly ...also the car is driven maybe 500 miles per year.. I will check all reccomendations Thanks very much Frank

jlex · jlex's Garage

My sister had a problem w/ belts breaking on her '88. I thought it was improper installation or pulleys were misaligned, but it turned out to be the bearings in the alternator were going bad and were putting a strain on the belt. When the alt. was replaced, the problem ceased. Oh yeah, she only put about 500 miles on her car yearly......my theory is those bearings got messed up from non use.

kidrock · 07-20-2010, 09:29 AM

+1 as pointed out so well by E Sully and Rusnak, 6 shims is an absolute must. You can make a note of shim placement as you disassemble. You can also play with any combination of the 6 that works best for your belt and alternator/fan. Take care to not overtighten the belt, as this will cause a strain on your alternator bearing(s) and/or cause your fan to make contact with the fan housing.