Belt Change

[Mr.FixitNorm]

Although the cam/balance belts on my '88 944S had only done 10,000 miles they were 6 years old !! so on the advice of many on here, I finally bit the bullet last week and had both the belts changed on my 944S , along with the hand brake shoes which had started to delaminate.

Just before I took it into be done, I started getting a random scraping noise from the offside rear. The owner and one of his mechanics at the garage I go to listened to the noise and said they thought it might be the outboard CV joint.

Although I said they could replace the CV joint they said they'd strip the joint first and examine it, the upshot was after it had been stripped and spent some time in the parts washer, there was no obvious damage or wear, and it was just the grease had gone hard. Once it was put back together with new grease it was fine []

Only thing I'm not sure about is that there's what I'm assuming is a belt whirr which goes up and down with the engine revs. I think my car has the auto tensioners fitted so presumably the belt tension is ok? ( all the belt guide rollers and tensioners were replaced as well ) Do cambelts have to `bed in'? I'm sure I read a post on here where someone else had a belt whine after it was changed and this went after the belt was retensioned once it had been on for a while. Am I right in assuming I don't need to have the tension checked ( - know this sounds a daft question but I'm assuming that's why you have auto tensioners[8|] )

Any ideas greatfully received as always.

Regards,

Norm

 

[bmnelsc]

I think the belts are a little noisy when new - Mine came with almost new belts so I don't know if they are getting less noisy or I'm getting used to it. You mention you had a CV joint making noise from old grease. I've been looking for a service interval for the CV joints and front wheel bearings with no success as it is not in the Porsche booklet or the Haynes manual (for 924). I would really like to know what the re-pack interval is assuming no damaged boots, etc.

 

[stevie d]

Am I right in assuming I don't need to have the tension checked

I've just had my belts done and I'm pretty sure you need to get them checked again after about 1k-2k miles once they have bedded in and stretched a little . I did a bit of shopping around for the belts and waterpump job and everyone I spoke to said they would need checking again .There is a section in the service record book specifically for garages to stamp and date when this work is carried out .

 

[Gordon Attar]

Belts and tensioners are a little noisy to start and you should go backafter a 1000 miles for them to be retensioned

 

[robwright]

To go by the letter of the law although they have auto tensioners you should still set the tensioner using the belt tension tool. Then retension after 1000-2000 K. Mine whined when I changed them but a little tweek and I mean very little of the tensioner and all was well []

 

[vincematthews]

Just had mine done at OPC Cambridge and they are tensioned with the Porsche tool not the auto-tensioner. They say retension with the Porsche tool at 2500 miles (should take 30 min of OPC time) and replace at 48000 miles or 4 years. They say belt may be noisy as it beds in and stretches but this should go after the 2500 mile retensioning. Hope this helps BTW 'they' is the Service Manager . . . . .

You mention you had a CV joint making noise from old grease. I've been looking for a service interval for the CV joints and front wheel bearings with no success as it is not in the Porsche booklet or the Haynes manual (for 924). I would really like to know what the re-pack interval is assuming no damaged boots, etc.

ORIGINAL: bmnelsc Do it anyway . . . it probably needs doing - it'll give you that feel good feeling []

 

[sulzeruk]

The auto tensioner is not an auto tensioner, you still need to manually adjust it to get it right. The balance belts are usually too tight which is where the whine comes from. The belts should make very little noise even when new. Alasdair

 

[delboy1974del]

i have the exact same problem. My car howls like mad now after getting the belts done at the end of Feb Ive sent it back in again as ive done almost a thousand miles and its not getting any quieter like the garage said they would

 

[sulzeruk]

Ask to see the garages tool that they use for tensioning the belts. Unless it is a good indie, most won't have the tools. Alasdair

 

[Mr.FixitNorm]

Right, I've been to the garage today and spoken with the owner, he said new cam belts often whine a bit when first done and he said they always retension them at 500 - 1000 miles. ( they do this as part of the original cost as well ) He also said that as they stretch when new it's safer if they're a little tight initially. ( Incidentally, he said the original belts were in pretty good nick, and he didn't think they would have failed anytime in the near future, but he did agree that it's better to be safe than sorry ) Although I've only done about 80 miles since it was done I do think it's slightly quieter than when I first picked it up ( or I've got used to it ! ) anyway I'm taking it back in about 8 weeks time to have it checked and adjusted, important thing is they're done. Not sure if it's my imagination but the car seems a bit livelier now ??? Still got a few things to sort out myself: oil change, rattle behind dash, trace water ingress to rear passenger footwell + nearside rear driveshaft - strip clean and repack CV's [] Thanks for all the reply's Norm

 

[Diver944]

I've now had my belts changed five times across both cars at recognised Independant Specialists and they have never made an excessive whining noise afterwards. If they do whine it is more often than not an inexperience with 944's and caused by the Balance shaft Belt being overly tight. The balance shaft belt is very long and should be much looser than most cars camshaft belts which is why there is a tensioning tool specifically for it. Experienced Indies who do this job every week can probably set the tension by feel, someone who does this job once in a blue moon probably cannot.

 

[vincematthews]

All this assumes that the Porsche tool 9201/2 has been calibrated and is giving accurate readings [&:] Not sure why you would want to retension the belts at intervals different to what Porsche specify . . . .?

 

[surrey 944T]

From my experience of running 944's on and off since 1995 the advice of 4 years is far too short an interval for a cambelt change - simply lining the pockets of who ever is giving you this advice. I have never had a belt fail and I've run them much longer than 4 years (but low miles). Its true to say better safe than sorry but 4 yrs with low mileage use is just silly.

 

[rcsalmons]

Like Al and Paul said - balance belt tension will cause a whine if too tight. Rich

 

[pauljmcnulty]

I have never had a belt fail and I've run them much longer than 4 years (but low miles). Its true to say better safe than sorry but 4 yrs with low mileage use is just silly.

Have you been in the position of taking calls from people with wrecked engines caused by belts over four years old? I have for about 5 years.[8|] It's rare for belts to fail, of course. But, most people do change their belts within the recommended time frame. So, with only a small proportion of cars running with old belts any number of failures is significant. Multiply it up by the number of owners who don't post on forums or admit to a belt failing when overdue and it's even worse. Belts have been known to fail under 5 years old, rare but not great if it's on your car. What I don't get is why you would risk it? It's a small price every four years for the belt alone, and if you're going to pay for it after 5, 6 or 7 years how much are you really saving? Might as well say don't change the oil, as it looks fine, or leave the air filter for a few more years. Worth it just for the peace of mind, I'd hate to drive around with a nagging doubt like that in my mind.