Porsche Enthusiasts Club Forum

My 944 S2 is squealing on startup for between 5 and 20secs while idling in neutral, then the squeal stops and doesn't come back till I start up again.

While squealing it gets worse if I rev, so I'm assuming it's one of the belts.

I can see two on the front of the engine.

Balance and Cam belts were replaced in September 2010 and retensioned March 2011 so I'm a bit dissappointed that they are still squealing (if it is these?)

Has anyone had any luck using Belt Spray? Any advice on diagnosing the squeal source?

All replies appreciated, I'm a new owner trying to do as much as I can myself.

Thanks in advance.

How about contacting the place you had the belts renewed & re-tensioned (unless of course you did it yourself lol!)
They should be able to advise.
Can you get someone to start the car and you listen under the bonnet to see if you can tell where the squeal is coming from? this may help in the diagnosis as other forum members may well have had the same problem.
Perhaps even make a recording and play it back over the phone to the belt people? if they are too far to visit!

Just another thought it may be the Power steering pump? I had a problem on my S2, the bearing squealed like hell on start up and then went quiet after a few seconds.

Your cam belt wont slip, well if it does your engine wont be running as it will be destroyed. Balance belts whine when they are too tight but not likely to go away after a few seconds.
Classic symptoms of alternator or power steering belt - easy enough to tighten.

Rich

110% it is alternator belt slipping after starting because it has been loaded up. Mine was very bad over the winter & I managed to adjust it whilst doing the oil change, which means undertray off. Although polyvee they do seem to be very sensitive to adjustment on the 944. Maybe because more modern motors use automatic tensioners on them.

Thanks for the quick response guys I've had a look at this. I could barely look into engine bay for fear of being deafened by the squeal, it's that loud and piercing! But I think it was the slightly fatter of the two front belts slipping ( the one running from the crank towards the front left wheel) Is this the alternator belt?

Just to confirm:

1. The belts I can see at the front of the engine are the alternator & power steering belts? Is this correct? Do they also drive the water pump?

2. I understand that you can't see the cam and balance belts with the bonnet open as these are behind a cover at the front of the engine? Correct?

The cam and balance belts were fitted and adjusted professionally so I'm not sure where they are, just knew they needed doing, and the garage was JMG in Bournemouth and I'm in Oxford so a bit of a trek, I may give them a call but I'm keen to have a pop myself if it's not to taxing?

Any hints on how to do the adjustment? I've got the 944 workshop manuals and PET catalogues but no hints I can find in there.

Many thanks in advance.

1. Yes from the front the PAS is left hand & the fatter belt drives the alternator on the right. Nope water pump is drive off the back of the cam belt & others have said if it slips the engine stops.

2. Also correct they are buried behind a cover which is a zillion 10mm headed bolts to get off.

Alternator belt adjustment is: jack up car & axle stands. Undo undertray mounting bolts & remove undertray. The alternator strap is threaded left & right. So loosen front pivot bolts (13mm I think) into alternator & crankcase. Slacken both locknuts (18 or 19mm if my brain isn't going) at each end of the strap & turn the plain bit in the middle to push the ends apart. You need around 6-8mm max movement in the middle of the belt, with your thumb, not much tighter otherwise you'll knacker the bearings in the alternator. The belt should have been swapped when the other belts were done but check it has no cracks at 90 Degrees to the direction of travel. Check it is OK & if it is replace undertray.

JMG are well respected and give free specialist advice to Tipec Members and since you had the belts done by them It may be worth a quick phone call anyway..
My Turbo which is now with them for Sale has been serviced by them for the last 4 years, its a bit of a treck from Lincoln but well worth it!

Cool.

Cheers guys, fantastically rapid and detailed replies, now to buy some axle stands!

tr7v8: Sounds straight forward once I'm in there but access is a little fiddly.

I've not got an oil change or service due for another few months so need to do it myself and don't want to pay the labour costs for some undertray nuts and four bolts!

If I didn't adjust the belt what are the risks if I let it keep slipping (other than coping with the terrible noise!). Are there any other long term concerns?

Great, thank you all, I let you know how I get on and it's nice to here a good endorsement for JMG, I was very impressed with them and they did me a free new customer inspection so got a good heads up on future expense. I will bear in mind the free advice to TIPEC members that is good to know.

Thank you.

If it squeals & slips enough then it damages the belt. The ultimate being the belt breaking, also it won't charge properly but that is a long way off. If it breaks then it is a PITA as no charge means it will stop eventually. These polyvee belts seem a lot more tolerant of abuse than the standard V belt. TBH the longest bit is jacking it up & getting the undertray off. Although the S2 engine I sold the back nuts on the adjuster were so tight I took the whole lot off & used the vice to get them loose!

[/quote]
If it squeals & slips enough then it damages the belt. The ultimate being the belt breaking, also it won't charge properly but that is a long way off. If it breaks then it is a PITA as no charge means it will stop eventually. These polyvee belts seem a lot more tolerant of abuse than the standard V belt. TBH the longest bit is jacking it up & getting the undertray off. Although the S2 engine I sold the back nuts on the adjuster were so tight I took the whole lot off & used the vice to get them loose![/quote]

Hmmmmm, interesting.

1. To confirm, just checked, all belts were new on last September so no issues there.
2. Regards stubborn bolts, all the hardware was removed and re-installed last September (for the whole enigne bay, a donor engine was put in) so hopefully should be ok on the rust front. Thanks for the heads up though.

Looks like that's Sunday sorted!