968 cam belt checks
Discussion
Can anyone enlighten me to the situation regarding cam belts on the 968? I’ve heard varying stories.
As I understand it the standard service interval specified by the factory for checking the tension pulley turned out to be not frequent enough and some cars experienced failures before the belts came due for changing. This seems to have got the 968 an undeserved rep for throwing cam belts. So the more “in the know” owners get the dealer to check the tension (not necessarily change the belts) more frequently than the factory specifications tell them to. If you don’t specifically tell the dealer to check the tension pulley then they will only do it as it comes due on the service schedule. Have I got this right?
So:
1) What is the official service interval for changing belts?
2) What is the official service interval for checking the tension pulley?
3) What is the recommended interval for checking the tension pulley on older cars (every service)?
The reason I ask is I’m trying to sell mine and the first question everyone asks is when the belts were done.
>>> Edited by t1grm on Tuesday 15th February 22:58
As I understand it the standard service interval specified by the factory for checking the tension pulley turned out to be not frequent enough and some cars experienced failures before the belts came due for changing. This seems to have got the 968 an undeserved rep for throwing cam belts. So the more “in the know” owners get the dealer to check the tension (not necessarily change the belts) more frequently than the factory specifications tell them to. If you don’t specifically tell the dealer to check the tension pulley then they will only do it as it comes due on the service schedule. Have I got this right?
So:
1) What is the official service interval for changing belts?
2) What is the official service interval for checking the tension pulley?
3) What is the recommended interval for checking the tension pulley on older cars (every service)?
The reason I ask is I’m trying to sell mine and the first question everyone asks is when the belts were done.
>>> Edited by t1grm on Tuesday 15th February 22:58
OPC Service Interval for belts is 5 years or 48K IIRC, although 4 years and 40K is the generally agreed "sensible" time to do it.
There are 2 belts to change - the camdrive belt and the balance shaft drive belt. Both should be changed. So should the tensioners to the balance shaft drive belt. It can be worth getting the Variocam chain and tensioner checked at the same time.
There are 2 belts to change - the camdrive belt and the balance shaft drive belt. Both should be changed. So should the tensioners to the balance shaft drive belt. It can be worth getting the Variocam chain and tensioner checked at the same time.
Dont know about the 968 and I may be muddying the waters here but the interval for the 944 S2 was 2 years or 60000 miles, when I read the service schedules though there was a belt tension check required at 24000 miles. I bet if you do a little more research you will find a tesion check requirement.
Always important to change belts at correct intervals, but 968 no more susceptible to failure than anything else. The big scare with 968's, and probably what your prospective buyers have heard about, is the cams. The sprockets can wear prematurely and lose teeth. Since the sprockets are an integral part of the casting, when they fail you have to replace the complete camshafts (£1,500 + job). To minimise the risk of this the camchain and variocam tensioner should be regularly inspected, and I think I'm right in saying that Porsche do not specify this as a maintenance task at any mileage, which is a bit of a bone of contention.
GR4 is correct - checking the chain tensioner doesnt form part of the official OPC service schedule. which is another good reason for using a reputable independent! To my knowledge 48k is the recommended interval. I had mine done every 3 years on the 944 and will continue this theme with the 968. it may be paranoid/overkill but to me its worth the extra £150 or so over a standard 12k service.
Punters asking about belts is an odd one, ok nice to know they've just been done, but its not really big dosh to just replace the pair anyway.
Those potentila buyers are being a bit shortsighted anyway as the cam teeth thing tho is way way way way way more important, on a 968 you've got to pop off the cam cover to check the cam teeth really on any potential purchace really- well I certainly would.
Coz as if you dont & the chain slips = mega ££, & even if there are teeth missing (which is very very common if its not had new cams- even on low mile cars) to replace the cams with gen porker ones is still over a grand.
Porsche refuse to acknowledge the cam teeth were ever an issue so its not a service/checked item, same goes for the tensioner & the now replacable tensioner blade.
Those potentila buyers are being a bit shortsighted anyway as the cam teeth thing tho is way way way way way more important, on a 968 you've got to pop off the cam cover to check the cam teeth really on any potential purchace really- well I certainly would.
Coz as if you dont & the chain slips = mega ££, & even if there are teeth missing (which is very very common if its not had new cams- even on low mile cars) to replace the cams with gen porker ones is still over a grand.
Porsche refuse to acknowledge the cam teeth were ever an issue so its not a service/checked item, same goes for the tensioner & the now replacable tensioner blade.
iguana said:
Punters asking about belts is an odd one, ok nice to know they've just been done, but its not really big dosh to just replace the pair anyway.
as a recent punter myself, I ALWAYS asked about belts because it was at least some indication of how the car had been cared for. a) had it been done b) did the seller know what I was on about (hence appreciate the importance of belts). ok it aint perfect but when youre staring at the unknown you get clues from anywhere. also if the cambelts were replaced by a good independent I was able to ring them and check that the chain tensioner formed part of their belts service. I did this twice and got one "no" and one "yes". again, far from perfect but still goes to form the final impression.
>> Edited by softinthehead on Wednesday 16th February 19:46
Does the 968 have a similar camchain tensioner to the 944?
My car had the camchain and belts, seals etc changed by the previous owner just prior to selling it to me.
This was done by a very reputable indie often mentioned on here. When I checked the invoice I couldn't tell if the camchain tensioner itself had been replaced. I phoned the indie who replied (worringly) that these weren't changed!!!
My friend had the top pad on the tensioner come loose on his 944 cab necessitating a £2000 top end rebuild.
I purchased a replacement camchain tensioner and changed it myself.
The top pad of the original tensioner (which is replaceable on it's own) was in good condition, obviously having been replaced not too long ago. However, the bottom pad (which isn't replaceable without changing the whole tensioner (£200 ish) had two very deep grooves worn in to it by the chain and looked quite brittle.
If in doubt change the tensioner - it is a simple(ish) DIY job taking about an hour.
My car had the camchain and belts, seals etc changed by the previous owner just prior to selling it to me.
This was done by a very reputable indie often mentioned on here. When I checked the invoice I couldn't tell if the camchain tensioner itself had been replaced. I phoned the indie who replied (worringly) that these weren't changed!!!
My friend had the top pad on the tensioner come loose on his 944 cab necessitating a £2000 top end rebuild.
I purchased a replacement camchain tensioner and changed it myself.
The top pad of the original tensioner (which is replaceable on it's own) was in good condition, obviously having been replaced not too long ago. However, the bottom pad (which isn't replaceable without changing the whole tensioner (£200 ish) had two very deep grooves worn in to it by the chain and looked quite brittle.
If in doubt change the tensioner - it is a simple(ish) DIY job taking about an hour.
I don't think the problem with cam sprockets occurs with 944's, or if it does it's rare. The 968 variable cam timing works by altering the tension on the cam chain, and any extra slack in the chain attacks the cam teeth. 944's don't have variocam. Because of this I would assume that the 968 tensioner is more complex and expensive than the 944 equivalent, but I've no idea how much.
>> Edited by gr4 on Thursday 17th February 10:35
>> Edited by gr4 on Thursday 17th February 10:35
The 968 cam chain tensioner costs around £600 while the 944 S2's costs £200.
The 944 S & S2 tensioner replacement is a one hour DIY job while on the 968 the camshafts have to be taken off the head.
On an S2 cam sprockets can also wear out depending on how worn out are the pads on the tensioner. I would find reasonable to have both upper and lower pads replaced at least as often as the timing and balance belts.
The 944 S & S2 tensioner replacement is a one hour DIY job while on the 968 the camshafts have to be taken off the head.
On an S2 cam sprockets can also wear out depending on how worn out are the pads on the tensioner. I would find reasonable to have both upper and lower pads replaced at least as often as the timing and balance belts.
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