It happened to me. My MCS was sold as a 2010 with a production date of 9/09. At 45,000 miles, it left a spot on the driveway. The next day it was pouring out, but only when running. My local mechanic correctly diagnosed the problem as a timing chain tensioner leak. The dealer checked my VIN and determined that I had the new tensioner. I've never heard the "cold start rattle". The mechanic said he unscrewed the tensioner with his fingers. All fixed now with correctly torqued (65 Nm) tensioner.

 

You will want to keep an eye on your tensioner.. Did you have the new crushed washer put on your tensioner?

 

By "new crushed washer" do you mean different design than the original?

 

The original tensioner didn't come with a copper crushed washer. So they started installing them with one. Even the updated tensioner itself at first didn't have the crushed washer. The crushed washer not only keeps it from leaking oil but also helps lock the tensioner in place so it has a less chance of backing out. This would be a new design. But it has been out for sometime now. You just want to make sure that if your tensioner has backed out you replace the crush washer with a new one. Never use the old one. Have you had yours replaced already/updated?

 

I'm in the process of replacing (installing?) a washer to stop mine from weeping. I'm looking for some info about the process (actually started a thread on it today).

 

If yours is/was weeping you will want to replace it. Do you have your tensioner out already? If you don't and are still driving it make sure the tensioner is tight. Sometimes when they start weeping that's a sign of the tensioner backing out.

 

It was actually called a "seal ring" (not washer). Part # 11 31 7631 972. Is that the same as a crush washer?

 

I haven't removed anything yet....still waiting on parts....need to replace valve cover also. Thanks for the heads-up.

and..

Crush washers...sealing washers, come in several types. They are usually soft aluminum or copper. Back in the olden days, we'd heat the used copper ones red-hot to soften them for re-use.

 

That is the same. the ones on the tensioner are of aluminum. Very soft so they crush and make a good seal. The concept is very similar to what is on the oil drain plug. which usually are of copper.

 

Very true..soft aluminum or copper. good luck on your repairs!