Purchased original MB valve cover gasket kit. Replaced both gaskets but the passenger side is still leaking in the exact same spot as before replacement. Anyone ever use Locktite 5900 spread lightly along the outer edge of the where the seal is on engine? Will this solve the problem? Also noticed that the bolt at the leak which I torqued to 8nm appears to be bottomed out. Perhaps a slightly shorter bolt here? Doesn’t look like the cover is warped, but wouldn’t take much. Engine has only 56,000 on it and maintained well.

 

year & model? approximate leak location?

 

2003 SL500. Lower right rear side, just at bolt/plug. I ended up using a tiny bit of RTV under the gasket at that point and a slight bit to cover the scratches as suggested by Rudeney. Unfortunately, I managed to squeeze out another leak near the next bolt forward bottom. Lets hope a new gasket installed the 4th time, is the charm. Though I do appreciate all the practice and speed at which I can now remove and replace a valve cover (only kidding), I really do NOT look forward to doing this again. Guess this time I will bite the bullet and just cover the entire lower half of the gasket with a bead of RTV along with a spear around all the bolt holes and keep my fingers crossed. Left side seems good to go after 50 miles of driving - and NO RTV!

 

there are issues with this engine and the 320 with leaky valve covers. other than the cylinders & plug configuration the 500 and 320 are pretty much the same engine. why one side leaks and other side doesn't is a good question. one should not have to resort to it but I used permatex black on the lower half of cover. it was the only way I could stop the leak. don't over torque or overdue the gasket maker. I filled the valve cover grove with rtv where the gasket sets in. don't want the residue getting inside the engine.

 

just finished fixing a leak on my r230 sl500 passenger side valve cover, new gasket and rtv black. only been a few days, so far not leaking. changed the plugs while everything was out of the way. 9 Nm on bolts and 8 on the coils. for me the new gasket by itself would last a few months before leaking again.