I have a 2008 CLK550 with a minor oil leak on the passenger side. Drips onto the exhaust manifold and provides the cabin with a very distinctive aroma. In preparation for replacement of valve cover gaskets (cam cover seals?) - I need to clean the engine bay.
Car has 120,000 miles, also time for new plugs so ---- may as well.

1) what is the best method for cleaning the engine bay? I have a pressure washer, but not crazy about that idea.
2) Anything else I need to look-at while I'm in there?

Will also change oil and filter, but what other items are 'might as well's' at 120k?

Thanks!!

 

Are you sure it's the valve covers leaking? That is very rare on the M272/M273 engines as they used black RTV instead of a formed gasket. Also, valve cover removal on these engines is a bit more involved than on the M112/M113.

The most common source of topside oil leaks on these engines are the cam plugs (left bank, rear of the head at the end of the camshafts), the oil centrifuge cover (right bank, read of the head a the end of the intake camshaft), and the o-ring seals on the camshaft adjuster solenoids (a.k.a. cam magnets), located on the front of the heads, two per side.

 

It is definitely rare but I had that same exact issue, passenger side leaking on exhaust manifold but it was a very small leak so I never really noticed a smell. My vehicle is also a 2008 CLK550. I even told my indy that I was very surprised and he also said he was as well (We had both a 02 CL500 and a 04 E320 and both vehicles had both gaskets changed around 100k miles).

 

The reason leaks on these are rare is because they use black RTV as a gasket, and a robot assists with its application when the engine is built. RTV does not shrink or crack like rubber gaskets. I guess it's always possible for a failure, but it would be very rare (not like the near-certain gasket failure on the M112/M113 engines)