'Chattering' on S2

[rcsalmons]

ORIGINAL: awattam

Sorry to hear about this.

Did you find out the reason for the failure? Was it the chain which failed and damaged the teeth or the plastic tensioner pad?

I replaced the pad as soon as I got the car (an easy job by the way and no need to change the rocker cover gasket on mine) but am wondering if I should have changed the chain at the same time now.

"The pad" - arent there 2? top and bottom.

Someone else has mentioned removing the front cam gear, becareful doung this as you will lose your cam timing if you are not careful I.e more than a fraction of a degree out when replacing the gear.

Rich

 

[trev260764]

This is interesting as tomorrow my replacement cam is fitted on the Blue Car. I'll ask what the situation is with the chain. The business with the chain stretching and only being £20 seems that it is a cheap maintenance job, the tensioner assembly on the same page at £276 seems less of a bargain. However on this article http://forums.pelicanparts.com/showthread.php?t=482309 a suggestion is made that the tensioner should last forever! Found this on line http://forums.rennlist.com/rennforums/968-forum/409911-diy-camshaft-chain-tensioner-pads.html not sure whether it helps with the chain "˜split link' situation. So, a slipper-pad is a cheap and easy replacement. The tensioner should last forever. The chain stretches and needs replacing from time-to-time, but can the chain be replaced without removing the cams? Surly someone knows? And I could do with knowing as I still haven't received the paperwork for my Red Car to see if any work has been done in this area. And I'm becoming nervous...

 

[awattam]

That second link (which shows for a 968 with variable cam timing) shows the chain having different coloured links in order to time the cams, not because they're split. I'll give a definite answer when I've got time to get my cam cover off again but I'm thinking the chain isn't split-able.

My course of action is going to be to inspect the cam teeth and chain very carefully, looking for excessive wear. I've already changed the top tensioner pad and have checked my tensioner. My top pad showed slight wear grooves but was not cracked or brittle after 140k. It was very discoloured however (yellow while the new one is white) so this may be a good indication of whether your pad has been changed at any point.

I inspected the lower pad at the same time I changed the top one and it didn't show any wear like the top one. I think the design is such that it's not subject to much force since the 'tight' side of the chain is at the bottom and the pad is simply a guide if the chain flops about. IIRC the lower pad is not available separately from the tensioner itself, which is quite expensive. Given that the whole lot can be checked inside an hour, periodic inspection of the whole lot isn't unreasonable to include as a part of a service.

If the cam teeth are starting to wear it's not necessarily a good idea to replace just the chain as both will have worn into each other. Changing the chain could accelerate wear of the cam teeth or could lead to the chain not disengaging with the sprocket teeth properly.

 

[trev260764]

Does that mean changing the tensioner £276, the chain £23 and both cams £1000 (£500 each) and timing belts etc at the same time? Oh, and labour. And water pump...

Think i'll get a Fiat Punto.

 

[rcsalmons]

If the tensioner isnt damaged no dont change it, just the slipper pads.

Have just done all the above on my 968.

Rich

 

[pauljmcnulty]

Does that mean changing the tensioner £276, the chain £23 and both cams £1000 (£500 each) and timing belts etc at the same time? Oh, and labour. And water pump...

That's why every time someone here asks for advice when buying a 16V 944 I repeat the mantra "check the history and get the cam condition inspected". It's not common to have to do the lot unless the chain and slipper haven't been changed when necessary, but often they've never been looked at.