Crackhead944S

Highway T, I believe they start with a 928 part number. So I would have to say that they probably also fail on 928's, only there are two of them.

I wonder if one fails on a 928 does it take the other with it? For example, the tensioner fails and then the stopped cam eats the timing belt which in turn stops the other bank of valves from opening and closing?

At least I only had to change one before it went.

gtroth

Older 928's (<'84?) aren't interference engines (well, at least when not covered with carbon), so at least you may not bust a ton of valves.

Any oil pipeline failures? Chain failures?

The tensioners do make wonderful paper weights, especially if you change them in time like I did. Guys pick it up, ask about it, get a little oil on their fingers, and think you're a stud (misconception, in my case).

Mine showed only minimal wear on the top pad (@90K), but it wouldn't compress for removal (still won't), so something was wrong with it.

hacker-pschorr

Some 928 info:

1. The chain tensioner did not start life on the 928 until 1985 US models (Euro's still had the 16V)
2. US 16V motors are not interference engines - Euro 16V's might be depending on the year
3. 928's are NOT known for the tensioner failing at any point. You'll spend a lot of time trying to find a 928 S4 owner who replaced the chain or pad. I've never seen a 928 loose the chain, tensioner, or pad. I'm sure it's happend at some point, but very very rare. More 928's were made than 944's with this setup and there are quite a few 150k - 200k 928S4's on the road with everything in the head original.

944_S_TYPE

Hmmm, Does anyone but allzims sell the tensioner pad?

http://www.allzim.com/acatalog/944_9...ioner_Pad.html

Jfrahm

Get it straight for Porsche for less than Zims. Zims just gets them from Porsche and adds a markup.

928s do not suffer the pad failure, possibly due to stuff like:
lower head temps
less tension on the chain
generally lower RPM operation

The pads get old and turn orange, but they do not seem to crack apart. I doubt it takes much more HP to push the 928 down the road, so the mean heat output of the engines might be pretty similar (within 15%) but the 928 splits that heat over two heads and thus two tensioner pads.

-Joel.

944_S_TYPE

Cool,
Are these the correct part numbers?
top# 928 105 509 01
bottom#928 105 347 01

What is the cost at the dealer? I thought they were unavailable?

Jfrahm

The top pad cost me $16 at my localr. The bottom costs more than the tensioner plus both pads, over $300 as I recall. The bottom pad can be safely ignored IMO.

You can check the part number with a search, I've posted it here before.

-Joel.