eohrnberger

With some of the stories that S2 rennlisters have told about the tensioner block breaking up and exploding the top 1/2 of their nice 3.0L engines, caused me some concern what shape mine might be in.

Since I didn't have any maintenance records specific to the tensioner or it's pads ever having been replaced (most all other records are there complete with work orders), I decided to pull the cam cover off and took a look for myself.

Sorry that I can't get clean picture of it, otherwise I would post it. What I saw was what I think is a slight hairline crack on one of the arms on the top pad (it could be a manufacturing mark of some sort), can't see the bottom pad, even with a little inspection mirror. There seem to be no grooves in the pad, as I can slide the chain back and forth a little bit and don't feel it catching anything. The oil tube looked shiny and new, and didn't have cracks or other imperfections that I could see either.

If it were replaced, it would have been at 165K miles in a large repair along with balance shaft belt, balance shaft seal kit, crank shaft seal bushing, crank shaft seal, oil seals, timing belt tension pulley, timing belt, water pump belt, water pump, water pump gasket. Unfortunately, this was all done by a Porsche technician on the side, so records are a bit sketchy on this repair.

Has anyone looked at their tensioner pads? Were they worn out? What shape were they in? How did you tell that they were in need of replacement?

Tom R.

the depth of the grove after about 70k is about the thickness of your fingernail.

the pad starts white but rapidly turns brown.

the pad is about $25 for the aftermarket part and about $5 if you get the 928 part number. the tensioner is the $$.

the bottom pads are not replaceable.

if they all the stuff you mentioned is outside the motor (you know what i mean) the cam chain and cam chain tensioner is inside. it is a dirty little secret that porsche doesnt tell anyont about the part needing to be replaced. see if you can get your nail into the grove. if yes replace the pad, or tensioner.

I ran an informal bar stool expert type poll here a few years back. results were change the pad every 60-70k, and the tensioner every 120-130k. if it wasnt done, change the tensioner to be on the safe side. i dont think there are recorded failures of the tensioner. falures of the chain yes, falures of the chain grabbing a cracked pad yes, but failures of the tensioners spring mechanism? I dont thinks so. YMMV

jonnybgood

If your pad has a hair line crack in it replace it now! $5 for the 928 top pad is easy insurance. I just replaced my chain and top pad. If there are no grooves in your top pad it may be fairly new but with a crack anywhere on it I would replace.

As Tom says, the tensioner doesn't seem to fail.

eohrnberger

To be honest, I'm not sure if it's a discoloration or a crack. I'm goign to look when I get home tonight, and I'll post a picture. Perhaps we can determine by the pad color how new it is.

Seems odd to me that you can't replace the bottom pad (I'm not doubting you, just wondering why). You'd think that if you had the tensioner out, that you could replace both pads.

Thanks for your insights.

AndyK

REPLACE the pad. Period. Not worth the risk.

eohrnberger

OK, replace the top pad (but you gotta figure the bottom one is in just as rough a shape, don't you?)

I'm going to need some help. While I'm pretty good with a wrench, this entire 'time the valves' part and the risk of doing it wrong, just makes me feel that it's beyond my present capabilities. Gonna have to figure out how to get some help, expertise, actually.

Tom R.

Andy is our resident fence sitter as you can tell.

Tom R.

You dont need help. Andy did his and Andy claims to have little to no mechanical skills. He will tell you the steps or where he got the write up. it isnt hard from what ive read. I have minimal mechanical skills but refuse to use them.

eohrnberger

I read the procedure at Clark's garage, and some of it is pretty befuddling, but it is a good write up nonetheless. Seems very involved.

AndyK

S2 Cam Chain Tensioner replacement

jonnybgood

Cam chain replacement is involved. Top pad replacement can be done without removing the cams. The bottom pad is subjected to minimal force and functions mostly as a guide. The top pad is attached to the actuator and pushes against the chain so it sees much more force and therefore, wear.

AndyK

You dont have to remove cams in the S2 to replace the tensioner. It is VERY straightforward, and, IMHO, pretty easy. Hardest part is removing the valve cover bolt that's under the fuel lines!

Follow the instructions, be careful, and it will be easy. Also, if you take the tensioner out, make sure to compress it before you try to put it back in!

eohrnberger

Cool. Thanks for the link. This procedure is shorter. I like it more already.
I already had the valve cover off. That was pretty easy. I took off the fuel lines, and bungied them off to the side so that I had unobstructed access to the valve cover. Just have to make sure that you use two wrneches to crack the pipe fitting, and all is easy from there.
Yup. Makes sense. And thanks again!

Hell, that procedure is nothing. Clark's Garage procedure went into the entire removing the cams thing. Is the chain at risk here, or is it just the pad and / or tensiorer assembly that need to be replaced?

AndyK

I think the chain rarely fails without catching on a broken tensioner/pad first. But at 180k...I'm not too sure. Anyone??

Clarks garage must have been talking about cam chain replacement, rather than tensioner replacement?

Anyway, be careful of the "J" tube. If you are rough with it, and bend it, a new one is VERY expensive! I reused my old one without problems. Just watch those 4 crush washers--very easy to drop them into the engine! The oil holds them onto the bottom of the tensioner...you pick up the tensioner, turn it over to look for the washers...and plunk, right into the cylinder hole!

eohrnberger

Yup. Will do. Thanks.