89 300 SE Head gasket help
 

Hi EVERYONE,

New poster here. One of the guys on the porsche board recommended your group, as knowledgable and helpful.
...My newly inherited 89 300SE is in dire need of a head gasket. The oil leak is now pretty bad.
I am a pretty good DIY Wrench, but need help on this one. Has anyone done this on a W126, have directions ... and/ or in the NY area and willing to point & drink, as I work?
Maybe I can talk the 19 yr old chippie next door into serving drinks while in the garage? ......I'll send the wife shopping.

Thanks guys, Ken

It's usually not the head gasket but the joint of the two piece timing chain cover. The only cure is to take off the distributor cap, rotor and upper cover, replace the 'U' shaped seal and reseal the cover with official MB sealant, loctite 5900.

I recently did this job on my 300SE and it's much better now.

BTW, the camshaft cover gasket has a half moon plug at the rear and this may also leak, IMHO.

http://www.peachparts.com/shopforum/tech-help/102977-m103-oil-leak-burning-3.html?highlight=m103+leak

http://www.peachparts.com/shopforum/search.php?searchid=96700

Do an advanced search on 'm103 leak', without the quotes.

The leak is very heavy at the rear of the motor, and running down to the passengers side .. along the head.
The half moon you mention still requires removal of the head? ..... and it seems like it is recommended to use loctite 5900?
Can I do this just popping out the half moon??

I really want to take the head off and replace the gasket & front cam cover gasket & seal also. I cant find a step by step guide?
I know this is not beyond my capability... but I need direction..........

The half moon is part of the cam cover rubber gasket. Make sure it hasn't popped out.

Loctite 5900 is THE stuff.

Member Stevebfl is a Florida Tech. Do a search on his name because he has really good answers.

The 103 motor in your car can develop a leak in the passenger side corner. Been there - done that. There is also the infamous U-gasket at the front of the motor, but as you mentioned, yours is at the rear.

There has been some talk on this forum about the rear corner 103 leak and also on the Ritter-Easley list.

I had my head gasket replaced and that cured the problem.

Whether you elect to do the work yourself or have it done, consider the valve guides and valve stem seals while the head gasket is being replaced.

Clean the engine and just make sure before doing a valve job.

Lots has been written on M103 and 104 headgaskets. I'd use only a factory gasket and new headbolts. Find a machineshop which is familiar with doing Mercedes work. They can clean the head, replace valve guides and face valves as needed.
Never done one on a W126- assume it's nearly the same as a W124.




Michael

in Texas