'95 S320 - Blown head gasket - PeachParts Mercedes-Benz Forum

sab · #1 06-06-2004, 05:41 PM

Hello,

Since my wife blew a coolant hose last year and didn't shut the car down before it severely overheated, I have noticed an oil leak which progressively is getting worse.
We finally chased it down and it is leaking from the rear right side, at the head gasket.
So I guess the head is coming off.

Can someone please give me some help? I need at a minimum the torque specs, but a writeup or the relevant pages from the shop manual would be awesome.

I would greatly apreciate any help or useful pointers.

Also are there any WYAIT tasks or items to replace?

Thanks and regards,
Sab.

myarmar · #2 06-06-2004, 06:54 PM

Great article by Steve Brotherton
http://www.continentalimports.com/ser_ic100345.html

Kestas · #3 06-06-2004, 07:56 PM

While there you can:

- Clean out the egr tube. The crud is most concentrated at the first few inches leading to the intake, and is easy to get at without the head.

- Considering the mileage, have the head completely inspected and reconditioned with new valve guide seals and perhaps new valve guides.

- The upper timing cover seal, by default, is part of the job. It's a procedure unto itself that you should learn how to do properly.

Torque specs require all bolts torqued in three steps as a group, 55 Nm + ¼ turn + ¼ turn. There's a special 12-pt bit used for the head bolts available at certain auto supply places.

sab · #4 06-06-2004, 11:36 PM

thank you very much for the info and the link to the article.
sounds like it is quite a job and the info on the harness is very scary. that would really put a crimp in the budget this month to replace the harness and tensioner along with all the other parts...

one more question: since my engine overheated, should i get this head rebuild, just planed or buy a used one?

great info,
thanks and regards,
sab.

blackmercedes · #5 06-06-2004, 11:45 PM

I'd be leery of using your existing head. You might want to investigate a rebuilt head from MB or other vendor, as that head might be leaking thanks to warping from overheating.

sab · #6 06-06-2004, 11:47 PM

i am fairly certain it is leaking to to warping from overheating, but i thought a machiene shop could simply plane a "warped" head. wrong?

stevebfl · #7 06-06-2004, 11:52 PM

Those motors are really strong and oil leaks from the front right and rear right side are common without doing any overheating. If you have no coolant in the cylinders or loss of compression between cylinders or into cooling passages (pressurizes coolant tank while cold), then I would verify the straightness of the head and just replace the gasket if not out of tolerance. I would probably accept .004inlengthwise and .002 side to sde.