M103 Valve cover gasket won't quit leaking
 

So, I've replaced the valve cover gasket, re-torqued everything down, etc. Still I get leaking in spots, and quite a decent amount at the rear of the block near the half-circle of rubber (typical spot).

I've replaced the breather hoses, etc.....

The only thing I haven't done is replace the cruddy peeling paint off the valve cover. I don't think that's the cause...

What could be causing this continued leakage? Do I just need to order another gasket and try again or is there something I'm missing?


-tp

Maybe the valve cover is bent or has a faulty seal guide so the seal wont set properly. Take it off and test it on a straight edge or a flat table, check the seal guides as well.

You using a cheap gasket or OEM? I've learned my lessons with crap ones, they don't seem to seal properly.

The M103 was designed to leak from the factory.


:D

I had to...

[QUOTE=pawoSD;2085097]The M103 was designed to leak from the factory.


:D

I thought that was only if they came with the option "External Lubrication System"

leaking gaskets
 

Typical torque specs for MB cam cover gaskets are quite low. For my 117 engine, the spec is 3 to4 Nm. Over torquing often produces distortion and subsequent leaking If your spec is similarly low you will need a 1/4" drive torque wrench since the typical 3/8" drive wrench is not sensitive enough at the low end.

You should also replace the copper crush washers under the bolt heads.

Good luck and let us know how it comes out.

[QUOTE=Hirnbeiss;2085183]That was part of their new, improved, rust-proofing system. :D It's designed to slowly coat the entire undersde of your car with oil.

[QUOTE=Dee8go;2085245]The original system came on 617 equipped vehicles....they then improved it for M103 vehicles....to have a more even oil distribution. :D :D

Well, I started off using really low torque, as you wouldn't expect to need much with a rubber gasket. That didn't work. So, I gently and evenly applied more torque. That didn't work either.

I didn't realize there were crush washers involved. I'll have to look into that. I guess I'll buy a new gasket and some new crush washers and give it a try. While I have the cover off, I'll strip it down and get it powder coated....


I'll post back when I've tried some of those things.


Thanks,

-tp

I've had them leak when the gasket got older and hard. Also, it's possible to mis-align the gasket fore-aft in the rear cut-out area. And then, it's also possible to have a leak at the infamous front cover that gets on the ridge below the exhaust ports and runs all the way back to the bell housing, making you think it's the valve cover.
The bolts on mine always turn down quite easily, and then quickly get firm, like they bottomed out in the head. I assume they are indeed bottoming out rather than oversqueezing the gasket. kinda like the metal standoffs on the tranny pan.

I wonder how you get that crap off the valve cover - It looks about a quarter inch thick. I have been threatening to redo my cover for 15 years.
Let us know how you come out.

DG

had issues with mine we used silicone to glue the rubber gasket to the cover - than put a light smear on the gasket to head surface and it been good -- jz

actually rocky racoon is correct...don't overtighted the valve cover gasket at all.....that seems right to me...if you over do the pressure on the rubber gasket it compresses it and it will start leaking after short use....yep....that's true

You also might want to consider the outside air temperature (OAT) if you're in an area where this drastic cold has been for the past couple of weeks. My garage stays just a few degrees above OAT and lately I've discovered a few strange leaks that have a tendency to repair themselves. I'm guessing temperature issues.

Do your process of ilimination at a normal OAT, or wait until this cold has moved on.

As I am in Illinois I, too, feel the pain of this environmvent....brutal.....

however, why 3/4" and 1/4" advise? That's not very Mercedes Benz like....shouldn't that be more metric?