vert

I picked up a 2003 c320 with 80K miles on it and trying to go through it so it can be a reliable car for my wife. I bought it from a friend who's had it for the last 50K miles and they've done the maintenance by what the car computer told them, which of course is not that much. No issues, no oil burning or anything like that.

While replacing the alternator, I took the air filter cover off to take a look at the top of the engine and noticed a lot of grime/dirt/oil build up. I know for a fact that my friend did not clean the engine for the last 5 years. Being new to Mercedes, I would like to get your opinion if this is a potential problem (leaking valve cover or leaking smth else) or if this is considered "normal" for this car considering the car's history I described. If it's a potential problem, what would you suggest I should check? I plan on degreasing the engine at some point to start fresh and see if I can notice a leak somewhere.

laneshift

Seems like you have a valve-cover leak. There isn't really a ready-made gasket to use, so most people just buy Black RTV gasket maker and reseal the valve-covers themselves. Easy job, the leak is not rare at all.

sinaa

thats the valve cover gasket leak pretty common on c240 and c320 m112 engins.
https://mbworld.org/forums/c-class-w...ing-cover.html

TNblkc230wz

I cleaned mine off and re-torqued the valve covers which solved the problem

Glyn M Ruck

Torque the valve covers, reseal the captive oil breather covers. Common & not really an issue.

Xhale707

Common issue.. but will be an issue if you don't do something about it

Be very very careful with the covers on top~ the screws tend to break very very very easily. I've done the job of re sealing the top part and snapped a screw. Once again when TQin go sloww

laneshift

Oh yes, I forgot that part. I had to extract the screw, you have no idea how SOL I felt when I snapped the screw off.

Glyn M Ruck

Use a known accurate torque wrench!

vert

What are the torque specs on the bolts? I will try cleaning and re-torquing first.

splinter

Specification is 8 Nm/5.9 ft-lbs/71 in-lbs. for the coil packs, PCV and cam covers’ fasteners. They're steel threading into aluminum so go easy.

Since you’ll be in the vicinity, consider replacing the spark plugs concurrently. Related thread…https://mbworld.org/forums/w211-amg/...ml#post3339541

vert

Those torque specs are very low, definitely will need to go very easy on those bolts!

Just to see if i got it right - there are small resurculating covers that are torqued to 71 in-lbs. These are the ones that are probably leaking in my case and for which I would use an RTV sealant if torquing them down does not solve the issue.

Then, there is a valve cover... What's the torque for that?

Glyn M Ruck

They are all 8 Nm - make sure that your wrench is accurate in that range !!!!!!

vert

Will do... Thank you all for contributing!