'97 E320 Head Gasket Question
 

My E320 is suffering from the notorious oil leak at the front passenger side of the cylinder head. I've read that the leak probably originates at the upper timing cover but ends up requiring a head gasket job to correct it properly.

Has anyone tried simply retorquing the cylinder head bolts first to see if it rectifies the leak? After all, I'd hate to fork out the cash for a head gasket replacement if re-tightening the head bolts would suffice. Comments welcome.


Ted

No, no , and really no.

Steve

Well, in my more optimistic opinion,

You could certainly try to retorque them, maybe you could be the first or one of the first to be able to put it off until later.

You have the straight 6 M104 engine right? I think that many memebers here with that engine expect the M104 gasket to break at a certain mileage. So it could be that it is just due now and that there is not much to do but get the proper job done.

You could certainly TRY replacing the front cover seal, You should inspect it to see if it's just coming from the front cover or not.
Gilly

Okay, I sprayed the entire area down with brake cleaner really good and got it pretty clear of oil residue. I then took the car for a 30 minute drive and reinspected it for an exact leak location. The oil appears to be exiting the engine through the seam where the upper/lower timing covers and the cylinder head/engine block meet. However, the head gasket itself seems to be weeping oil also.:(

Question: I believe I'll replace the rubber horseshoe gasket and reseal the timing cover tomorrow evening. Is there any harm possible from re-torquing the head bolts to factory specs while I have the timing and valve covers off?:confused:

Thanks,
Ted

Yeah, you don't wanna do that, the last 2 tightening stages are angle torques, so unless you want to loosen them and start over you'll never get it right.
The oil can creep back from the lip seal making it look like a headgasket. 'Course it could actually BE the headgasket too....
Gilly

Okay, Thanks. I'll just replace the horseshoe gasket and hope that corrects it.

Ted

Or, sheeesh I dunno you could maybe angle-torque say 1/8 of a turn exactly on each one, likelyhood of really ruining anything or making it worse probably slim to none. I'd do that in the normal sequence, not starting at one end and going to the other. There are maybe a couple of the smaller bolts up front that are just a torque, not an angle torque, and those you could certainly just retorque to the factory spec, but not higher.
Gilly

I just got done replacing the horseshoe gasket and resealing the timing cover. The procedure was a piece of cake with the help of a few tips that I picked up in the DIY section of this forum. Just as a precautionary measure I'm going to allow the sealant (MB # 003 989 982 010) to set up until this evening prior to starting it up.

I didn't attempt to re-torque the cylinder head bolts yet, but I will try Gilly's 1/8 turn angle torque method if the leak is not corrected. After all, what would I have to lose if the headgasket needs to be replaced anyhow?

Ted

FEARLESS

Are you aware there was a merc TSB reducing the oil capacity on the 104 engine from 7.5 to 7.0 litres.

Your oil level should be no more than half-way between min and max on dipstick.

If you are overfull, reducing the oil level can cure leaks.

Regards

No, I was not aware of this. Thanks for enlightening me, I will take note of this guideline when I change the oil/filter this afternoon prior to restarting the vehicle.

Ted

Alright gentlemen, I waited a day and a half to make certain the sealant completely cured prior to starting the engine. I also changed the oil and filter while observing the previously mentioned 7.0 liter capacity. After starting the engine and allowing it to run for about fifteen minutes, minor seepage still seems to be emitting from the front edge of the head gasket.:( I am 100% certain that the leak is NOT originating at the timing cover seam though.

My next move will be to re-torque the head bolts 1/8 turn as Gilly suggested earlier. Maybe it will help, maybe it won't, but we'll never know until someone gives it a shot right?:) I'll report back with the results later this afternoon.


Ted

Re-torqueing is a long shot. I hope you don't do any permanent damage. I wouldn't re-torque myself, but what the heck do I know? If you do end up having to replace the head gasket take a look here:

http://www.peachparts.com/shopforum/showthread.php?p=538878

http://www.peachparts.com/shopforum/showthread.php?p=194343

http://www.peachparts.com/Wikka/M104HeadGasket

Good luck!