96 C-280 Head Gasket Leaking Oil
 

Understand not uncommon problem on 104 engines, but this one is more than I want to tolerate. Looking for shop manual type info on head gasket replacement that I plan to do myself. I think I can get info on microfische from MB-USA. I got head gasket set from Germanstar that came without valve cover gasket and perhaps upper front cover gasket. I am considering retorquing head bolts (about an additional 15 to 20 degrees) but local dealership shops indicate they haven't had any luck trying this approach. I also understand the the replacement gasket is a modified gasket (it does come with a already applied bead of gasket sealer which I wouldn't be surprised to find is Hylomar HPF). A little apprehensious as head bolts are stretch bolts. This is my first MB and have little experience thus far. Have replaced front pads and serpentine belt though. From reading this board, have also concluded I need to replace shifter/linkage bushings.

Any suggestions or comments on similar problem and solutions and possible source of literature will be appreciated.

Hilton

Do a search on the archive you will find alot of info re:head gasket.

Try the retorque first
 

Yes they are stretch bolts, but they are steel and and extra 20 degrees or so will not cause them to break. Getting them to move in that direction might be difficult, although you mentioned the dealership already tried so they may move easier.

Are you getting oil in the coolant, or just an external leak?

If it's in the coolant, don't discount the fact that it could be a broken trans cooler within your radiator.

Good luck!

~Paul

__________________
'91 300E, 215K miles

lLeaking (oil) head gasket
 

Thanks Paul for encouraging note on retoque. My head has not been re-torqued, shop just indicated on similar problems they had had little success. It is external leak, right front corner and rear of head. Normal oil pressure on this engine is 70 to 75 psi whereas many engines run 40 to 45 which is part of the problem, I suspect. Ford 351 cleveland engine ran 70 to 75 psi oil pressure as it too was built to tight tolerances but it had heavy heavy cast iron heads.

I will also do search.

Hilton

Leaking M104 Head gasket
 

As indicated in other posts here, there is a special version of the gasket and special sealant which are used to cure this problem.
Leaks can also occur around the timing gear cover seal, so do it too. Also, the head bolts should be replaced. It wasn't until all of this was done that the leaks with my '97 M104 were cured - thankfully under warranty. Good luck.

Leaky head gasket
 

Thank you okc329, I hope I have the special gasket.

Does anybody know if the special gasket is made by 'elring' and comes with a red bead of sealent applied to bothe sides?

I was told that HYLOMAR HPF made by Permatex was used on head gaskets on Rolls Royce engines. I looked up this sealent in a NAPA auto parts store product book and it said that this sealent was developed for RR, BMW, Audi, Jaguar and other luxury European auto manufacturers. Does anybody know if this is the correct special sealent?

The bolts shouldn't have to be replaced unless they have stretched beyond the tolerance limit.

Do you know if they had to mill your head?

Thanks again,

Hilton Smith

More on Head Gasket
 

Did not have to mill head. However, I heard a rumor that the drilled/tapped holes in the block were not deep enough to accomodate the bolts if they stretch even a little. Have also heard that the bolts have some natural tension which they give up the first time they are removed. Suggest that you do search on site for the brand of gasket you have. I believe there is a post out there which says which gasket version is the best. I don't know if there is any definite info about the sealant that seems to work best but I bet if you put out a specific querry, some of the regulars will give you the info.