Failed Chain Tensioner?
 

Fired up my beasty after she was sitting for a fews weeks in the garage while winter raged on. Once warmed up, I heard the dreaded "chain over trash can" noise emanating from the right-side chain cover. What perplexes me is the car only has 40,000 miles, has had regular oil changes, and complete service records that suggest the PO's took good care of her. Is it possible for a hydraulic chain tensioner to fail so soon?

I'm pretty certain it's a bad chain tensioner, because as soon as I give her some revs, the noise disappears. At idle (800 RPM), I've got about 1.5bar of oil pressure.. that should be enough to keep a tensioner extended?

Any ideas folks?

I'll be opening her up today to have a look-see. Photo's will follow.

IMO your chains have stretched. Your actual oil pressure surely is enough to pressurize the tensionner. keep us to date with pics of the culprit.

Chains stretch should be relatively equal on both sides if the chains are equally old.
My vote is for tensioner or chain ramp failure.

Now I'm no expert, but everything appears to be in the right place?

Your thoughts?

http://forums.pelicanparts.com/uploa...1202602065.jpg

http://forums.pelicanparts.com/uploa...1202602097.jpg

I should note that's it's clean as a whistle in there. No gunk, little varnish, no bits of plastic or metal.

Mind you, I really have no idea what I'm looking for. I suppose I could try new tensioners first to see if that fixes matters.

i have no idea what the issue is, but you might as well install those chain tensioner collars while you have it open. i guess those prevent the tensioners from complete failure.

Maybe it's just me, but the tensioner on the right-side looks like it's extended quite a bit. It may be the angle of the photo, but the chain looks to close to the bottom of the chain ramp, to me.

While I agree that the RH side tensioner is extended more than the left side, it's not really as bad as some of the other tensioners I've seen posted to this site. There's about 1/4" gap between the chain and the chain ramp.

Or am I in denial? (See close-up photo below):





http://forums.pelicanparts.com/uploa...1202604808.jpg

Safety collars only work on non-pressure fed tensioners. With Carrera tensioners you can insert thin tubing inside the piston bore, aka "Jerry Woods" tensioner mod (pictures and details here by aigel).

Trog, If you decide to do the mods, let me know. I'm in the installing Carrera tensioners this weekend myself. I found a piece of brass tubing that is perfect size and I have more than enough length to do few sets of these.

Those chain tensioner collars are for the mechanical tensionners.

My experience on chain tensionners...:
http://forums.pelicanparts.com/porsche-911-technical-forum/311387-3-2-timing-chain-noise.html

Trog - Did you check the oil level before removing the covers? I'm assuming it was okay?

One of your chain tensioners has collapsed. Engine oil pressure does not supply the pressure that keeps them hard - the check valve in the bottom is what keeps them from collapsing. Can you collapse the tensioner with less than atlas strength?
When they are working it takes a vice or big channel locks to collapse them as the oil slowly weeps out the top.
-Chris

Get a small flashlight and look down the chain and see if you can see if it has been rubbibg the case...(if you haven't already)

Here's a collapsed tensioner. From my right side last September.
http://forums.pelicanparts.com/uploa...1189296057.jpg

Check the clearance distance between the chain and the plastic ramps.

Put it back together and record the sound it make. From the look of your tensioner I don't think that the problem.

Zef, I read your post.. how did you resolve the problem in the end? Did you change-out both the tensioners and the chains?

Yup, oil level is A-OK.

Won, you have mail.

Trog, if your tensioner collapsed, it would look like my pic. I can compress my bad tensioner with my fingers, the good one, I can not. I'd investigate a bit more before spending $450.- for two new tensioners.

Dave