Al Cody

The 944S and S2 (928 S4 as well?) seem to break cam chains around the 110 mile mark. This seems to most commonly be the upper foot pad breaks up resulting in a broken chain. My question for the high milage cars is:
Have you replaced the whole tensioner? Or top pad and chain? Or just top pad? Or not at all?
My 944S is at 110K miles. I've replaced the top pad, but nothing else. I'll do the chain soon. How nervous should I be???
The tensioner itself seems pretty simple and I think it should have a very long life.
Does anyone have a current source for the bottom foot pad?
Thanks guys.

Michael Stephenson

I am not sure that the bottom pad is available, but I bet one could be made from a top pad. Most people get a whole new tensioner as the common wisdom is that the tensioner does not tension as it should at around 120K.

I replaced my top pad and I think that will hold me until I get to the 120K mark.

The chain is cheap, but it takes some special tools to install it properly - not something I would do myself, but you may be good enough, just make sure that you have the Porsche supplement for the 16 valve motor (vol. 1A, I think) and that you are very familiar with the procedure before you begin.

Also, if you do not have a torque wrench that is made for low torque, then get one. I ended up over torquing my bolts using my 100 lb torque wrench set at 7 lbs and I had to put heli-coils in. (that reminds me that I need to double check to makes sure that they are holding well...)

AndyK

I replaced my tensioner at 100k (when I bought the car). Compared to the brand new one I bought to replace it, the old one looked and felt just as new. The pads did have deep grooves in them. The bottom pad had a 928xxxx part number...not sure if they're available though.

I say to be completely safe, get a new tensioner with new pads. Otherwise, you are probably fine replacing the top ramp. But if the bottom pad breaks...could be a very costly mistake!

Z-man

It is best to replace the whole unit, not just the top pad, IMHO. Don't forget, the tensioning unit between the pads will have about 100k miles on it, and it too can be a little tired due to age and wear.

BTW: when I had mine replaced at 120k miles, the top pad was so brittle, it broke apart in my mechanics hand! Talk about being on borrowed time!!

-Z .

Al Cody

Thanks for the replies. I'm adding a tensioner to my wish list.
I agree the bottom tension pad is a problem. Otherwise I think I'd stick with a new chain and new pads. I had thought about trying to modify a top pad to fit the bottom. The down side is pretty big if it breaks up.
I have three torque wrenches in fact. I'm a big fan or correctly torqued nuts and bolts. Cheers

Tom

There is a world of difference between replacing the tensioner (a relatively simple job) and replacing the chain (remove the cams). The chain is not generally a problem. If you really want to spend a lot of money, or to worry, consider that the sprockets on the cams that the chain goes between are also subject to wear so you would need to replace the chain. I felt comfortable just replacing the tensioner.

pete944

The chain and the sprockets on the cam wear together. Just replacing the chain can cause the sprockets to wear at a faster rate. Probably not a whole lot but I thought I'd mention it.

Rally Guy

I think its about a 10:1 cost ratio - which is well worth it to me...

~$350: Tensioner
~$3500 Top end rebuild (when tensioner fails)

All prices are est. in CDN $.

I replaced the tensioner (my BOTTOM pad was heavily worn too) and painted the cam cover while it was off.

Totally worth it.

RK