New belt stretched and slipping

[mhall1019]

'02 turbo 70k miles - I replaced serpentine belt as part of 60k service. Old belt had evidence of 70k mileage but was causing no problems. Replaced with correct ContiTech (not Genuine) belt and 5 months later when finally got car back together, within 2-3 engine starts, the belt tensioner was at its limit and the belt was slipping and squealing. It does this for 30-60 seconds after starting and then stops. I took the belt off again after about two weeks - 300 miles - and, other than the fact that the belt is apparently stretched, it looks perfect. The idler and tensioner pulleys all turn smoothly. My next step would be to put a new aftermarket belt on to see if it happens again - its easy enough to do and they are cheap and I think good quality. Unless someone has an idea of what would make a belt stretch so quickly?

Thanks,

Mike

[Loren]

The belt will stretch a little when it's warm.

I would check the pulleys to make none have any wobble and replace the belt with the Porsche version.

[mhall1019]

The belt will stretch a little when it's warm.

I would check the pulleys to make none have any wobble and replace the belt with the Porsche version.

Loren:

Thanks. The belt when cold is already stretched to the point where the tensioner is as far as it can go counterclockwise. It only squeals just after its started up. It makes me think that one of the driven devices (water pump?) seized up while it was sitting for 5 months and has some residual friction until it gets spinning. I hate to experiment with a $100 belt. I wouldn't hesitate to spend the money on the genuine belt for the next 60k miles, but if it stretches after 3 engine starts, it will get expensive fast.

Thanks,

Mike

[topmech0]

The belt will stretch a little when it's warm.

I would check the pulleys to make none have any wobble and replace the belt with the Porsche version.

Loren:

Thanks. The belt when cold is already stretched to the point where the tensioner is as far as it can go counterclockwise. It only squeals just after its started up. It makes me think that one of the driven devices (water pump?) seized up while it was sitting for 5 months and has some residual friction until it gets spinning. I hate to experiment with a $100 belt. I wouldn't hesitate to spend the money on the genuine belt for the next 60k miles, but if it stretches after 3 engine starts, it will get expensive fast.

Thanks,

Mike

think its most likely the 'cheap' belt but double check you have the belt routed around pulleys correctly as it will fit in 2 or three ways but only works correctly in one!

[mhall1019]

Loren:

Thanks. The belt when cold is already stretched to the point where the tensioner is as far as it can go counterclockwise. It only squeals just after its started up. It makes me think that one of the driven devices (water pump?) seized up while it was sitting for 5 months and has some residual friction until it gets spinning. I hate to experiment with a $100 belt. I wouldn't hesitate to spend the money on the genuine belt for the next 60k miles, but if it stretches after 3 engine starts, it will get expensive fast.

Thanks,

Mike

think its most likely the 'cheap' belt but double check you have the belt routed around pulleys correctly as it will fit in 2 or three ways but only works correctly in one!

I have ordered a genuine belt and will install it after I've checked all the pulleys out. But, I have lots of confidence in Continental belts - its all that I used in many Porsche engine rebuilds (up to 3.2Ls) and in servicing 964s and 993s and always thought that they were the OEM supplier. I am really trying to get to the root cause of the problem of why a good quality belt would stretch in 1 hour of operation. One reason may be, as has been stated, that it a cheap belt (or just a defective one) and putting a factory belt on will fix that. However, if there is something on the engine that would have initially caused the belt to stretch and now has a high resistance to start spinning when its cold, it will just stretch an expensive belt and keep on squealing.

Are there really multiple ways to route the belt that will still make everything turn in the correct direction and end up with the tensioner pulley in range?

Thanks,

Mike

[wvicary]

Conti belts are one the best you can buy unlike the Dayco or Goodyear belts. I would think that you incorrectly installed the belt and don't have it routed correctly.

[mhall1019]

Conti belts are one the best you can buy unlike the Dayco or Goodyear belts. I would think that you incorrectly installed the belt and don't have it routed correctly.

That has been my experience with Conti belts too. I will recheck the belt routing, but, is it really possible to have everything - power steering, alternator, A/C, water pump, whatever else - spinning in the right direction and have about the right amount of slack in the belt if it is routed incorrectly?

Thanks,

Mike

[wvicary]

Wouldn't be the first time I have seen one of these belts installed wrong. I'll try and post a diagram of the belt when I return to work.

[topmech0]

Wouldn't be the first time I have seen one of these belts installed wrong. I'll try and post a diagram of the belt when I return to work.

yes it is very easy to route the belt wrongly around idler,tensioner and deflection rollers and still have everything working.its not that its installed and driving pulleys wrong way its simply that the routing maybe wrong!

i have used many contitech belts and only had problems with SOME 3.2 or 993 but never the polyrib type on 996,7,or boxster

[jpflip]

The only good drawing I can find....

[mhall1019]

Well, it's confirmed. I can't follow simple directions. When the belt is routed per the factory drawing, it fits. It's also confirmed: there's more than one way to run the belt and have it seem to be on right except for a very loud squealing noise. Thanks to everyone who said to read the directions.

Mike