2005 Roadster has 41,000 miles and was told valve covers are leaking. Looked on line and it appears to be a common problem. Many people said they have replaced their gaskets multiple times. Any suggestions to prevent repeat problem? Told it would cost $795 to fix at dealer. Why so much?

 

Because you are going to a DEALER, that is why it costs so much. Why are you talking to a damn dealer? Those pretty showrooms, that 20 acres in the best part of town on the busiest street - it all costs money. YOUR MONEY.

Find a shop near you that you trust - one that is known to be good with Mercedes products and I will BET YOU your quote will be half that. There is a tuorial here on this site that tells you how to correct this yourself - and if you care not to try it yourself (I would not!), then print it out and take it to one of those shops and see what they quote you!

Here you go:
https://www.crossfireforum.org/forum...over-leak.html

One of the top ten issues with these cars. Don't get ripped off.

 

Hey Pizza? Why would you not recommend this as a DIY? It seems pretty straight forward, and pretty much like every other valve cover I have ever done.

 

Just did mine last week. Hour of work and no leaking since. Total was $10 for Ultra Black RTV and degreaser

 

did the same, works great

 

I don't recall ever reading about owners having to doing this fix more than once.

 

It's happened.
Do it right the first time.

 

And this entails merely making sure ALL traces of old sealant be removed.

Then, thorough de-greasing before using the proper sealant.

Pretty danged easy. Total cost? ~ $12.

 

And this entails merely making sure ALL traces of old sealant be removed.

Then, thorough de-greasing before using the proper sealant.

Pretty danged easy. Total cost? ~ $12.

And, since no one else pointed this out:

I doubt seriously that it is the valve cover gasket(s) that are/is leaking. It will be one or both of the "Breather" covers on each valve cover. They're sealed with an RTV-type sealant.

Apparently this is one area of expertise the Americans have over the Germans! The OEM stuff they used is...crap.

 

Maybe, but it is possible that the American stuff is made in China.
I doubt the German sealant is any worse than the stuff we use, I expect that it has been applied wrong in the first place.

 

Sorry, bud. The OEM RTV may be fine-just not in this application. I've done quite a few of these. The OEM is not oil/gas resistant. And very soft/slimy after a couple of years. The Black Permatex recommended by me and others is made just for this app.

The first time (I'll get to that) mine leaked, it was under warranty. The tech at the dealership said himself that the stuff used was crap. and promptly proceeded to apply the right stuff. Right over the old crap without benefit of cleaning it first! It leaked within 20...minutes and required me to do the job right. 2008.

Ahhhh-the value of having a warranty and trained techs to tuck us into bed....

As for not being applied correctly-I disagree. Every one I've seen was machine (robot)-applied. Very even bead and complete coverage. The stuff just melts with time, oil and heat.

 

I wondered if they used a robot on this stuff. I saw a robot applying it on an engine once somewhere. The robot is only as good as the hand that set it up anyway.

I have had two cars, one from new and it never leaked in 20,000 miles. The one I have now shows no sign of leaking at 28,000 miles. Not sure if it was fixed before but they look neat and tidy with no spill over at the edges.

The secret is the right amount applied evenly and as directed. Done right it should never leak.

 

I have been told by a Crossfire certified mechanic the secret to do the job right is the torque pattern on the valve covers. He said most people will just bolt the valve covers back on without honoring a pattern for torquing the bolts so the casket gets pinched or the valve cover does not sit right. Any comments?

 

I had no torque pattern to follow. I just brought everything finger-tight and eased them in. I don't remember the spec, but I did use a torque wrench.

 

Fixed mine over 2 years ago, no leaks since. Just used the high temp RTV and followed directions. Did not over tighten screws. works good last long time!

 

As with any part that is quite flimsy you start with finger tight and increase the torque setting a little at a time until they are finally all torqued up evenly. The last thing you want to do is bend the the main covers or the little ones permanently.

 

If you're going to use a torque value for the small M5-0.80x16 mm SHCS's. I'd suggest the 5-6 N-m I found in the shop manual. These are aluminum and, as stated earlier, don't need to be any tighter than slightly above snug. Otherwise, these screws are prone to shearing during assembly since the yield stress is very low.

I'd also recommend replacing these screws once you remove them during the repair. Not a good maintenance practice to re-use these because they are aluminum.

Or you can opt to replace these aluminum screws with corrosion-resistant steel versions (some folks use SS, too) and get away from the weak aluminum screws. But as onehundred80 stated, one has to be careful to not over-tighten these mounting screws as the aluminum-magnesium breather covers could experience permanent deformation/warping due to excessive fastening loads.

 

Now I have found a leak....seems to be more apparent since I added the sea foam to the il to clean it out. I havent driven it ,so as soon as I get the engine cover and the bigger throttle body I will do it all at the same time.

 

Valve cover gaskets take about 2 hours to do properly. Remove engine cover, all coil assemblies, disconnect fuel line at fuel rail, remove breather hoses from valve covers, remove complete valve covers, remove breather covers from valve covers, clean nasty old black sealant (the most time consuming part of the job), clean mating surfaces for valve covers at cylinder head, apply new sealant to breather covers and reinstall breather covers, place new valve cover gaskets on valve covers, re-install everything in reverse order. I believe the spec for valve cover torque is 9Nm (this is what I do at least). The only thing I would be sure to have is a good applicator for the sealant. M-B recommends between a 1 and 2mm bead.