sbmellen

As my mechanic is working on my car's second bout with leaky cam seals (1st done at 70K, doing 'em again at 89K) he finds that the right side bank's cam chain tensioner is shot.

How common is it for these things to go kaput? And why the hell did VAG put plastic on something that's obviously going to get frickin' HOT?

Here's the piece in question. Cost? $518 apiece (1 per bank).
<img src="http://img.speedycarparts.com/live/A508384741OES.JPG">

Kris Hansen

you don't want metal in there, as the chain slides over those plastic pieces. The worst it will do is rattle.

por911

The cam tensioner seals tend to leak but thats because of another issue. Unless the plastic chain ramps have broken or the the tensioner is completely collapsed, why replace it? They can get noisey, but if you use thicker Mobil 1 , that will go away. The only cars I've ever seen the plastic chain ramps break on is Porsche 944S2's and rarely, 968's.
If the car had high miles, I would replace the cam chain.

sbmellen

And that otherwise it was about to fall out.

Kris Hansen

but there's no weight involved. Your mechanic is pulling one over on you. THere is NO way to tell those things are going to fail, they can't really fail. There is a spring inside.

You sure he isn't talking about the cam BELT (aka timing belt)tensioner?

por911

Its bolted in place and the cam(or valve cover)cover is bolted over top of it(locking it in place). There is a pic of a similar version over on the 1.8t.org site.
If the tensioner starts to collapse, it does not fall out of place. You'll just hear alot of valve clatter and possibly damage the valves if fully collapsed. Never seen one fail completely yet, but they seem to be quite weak when they get a few miles on them(make the valves noisey) and don't seem to hold up with 0-5w motor oils.
With 70k on ours, I run Mobil 1 15w-50 and the tensioners &amp; valves are as quiet as can be. Next timing belt change(120k for me)I'll replace the tensioners and chains.

®ob

I'll sell you a good used one for half of that. Email me if interested

sbmellen

Anyway, he replaced that one cam chain tensioner.

We'll see how it sounds now.

TunersWarehouse

Man, I don't want to say this guy is off on his diagnosis. So a couple questions Is the chain tensioner out of the car? Or is he looking at it in the car. If it's in the car the only way to teall is to compress the upper part of the tensioner and see if it pumps up. There is a toll actually pictured in your image example that holds the tensioner down when you install a new one. Have him depress the top of the tensioner and then remove that tension and see if the tensioner puts firm pressure back on the chain. If so I doubt it's bad.

sbmellen

Brand new one is already in the car, sorry. =(