M103 Oil leak or burning?

[lino]

My 1989 M103 engine is losing oil. I'm not sure if it's buring or leaking.

I have read that the M103 leaks Oil at Top of the Timing Chain Cover, because of the gasket. I have also read that the M103 leaks Oil near the right rear of the engine block - Head gasket. I'm not sure how much oil the M103 engine normally burns.

In my car I see some oil on the plastic guard under the engine below the alternator. I'm not sure if it's freah oil or old. The right rear of the engine block looks dry. I took a quick glance. I will give it a thorough look and then I will clean the engine to see if there are any visible leaks/spots. I'm not sure if the engine is burning oil either. The previous owner spent a lot of money maintaing the car. I was looking in the service records and found this:

14MAY99 189 338 km
Wheels - Two, R & R $57.32
Brake Pads Rear R & R $19.92
Cylinder Head - Single, R & R $602.91
Replaced Exhaust Manifold Gaskets $99.60
Engine Cooling System, Flush $349.21
Inner Door Panel - On One Front Door, R & R $490.64
Door Lock Cylinder - For L/Front Door, R & R /Replace If Required $33.20
TOTAL $1652.80


27OCT97 179 989 km
Exhaust System - After Catalyst/Front Pipe Connection, Replaced $612.89
Belt Tensioner Shock Absorber - Single Belt Drive Replaced $91.23
Automatic Transmission (722.0 TO 722.4) R & R $356.40
Crankshaft Driven Plate/ Ring Gear R & R $32.40
Starter Motor Replaced ( While Transmission Is Removed) $446.92
TOTAL $1539.84

***Cylinder Head - Single, R & R $602.91
Does this mean the Head Gasket was replaced?

BTW- Does anyone know what this is:
***Automatic Transmission (722.0 TO 722.4) R & R $356.40

Thanks in Advance

[sixto]

Check for an oil leak on the front right of the engine below and behind the distributor. It will leak down to the alternator then to the plastic cover or ground. You can ususally fix this leak with a new horseshoe gasket.

Sixto
95 S420
87 300SDL

[lino]

Originally Posted by sixto

Check for an oil leak on the front right of the engine below and behind the distributor. It will leak down to the alternator then to the plastic cover or ground. You can ususally fix this leak with a new horseshoe gasket.

Sixto
95 S420
87 300SDL

I will take a look. Thank you very much.

[Gilly]

Yes the "R&R headgasket" means the headgasket was replaced.
The other one, the R&R Transmission 722.0-722.4 means the transmission was removed. It's all rather cryptic, but I am assuming they may have had to replace a cracked "flex plate", which is what drives the torque converter. Either that or there is more to that work order you're not saying, like they resealed the front pump in the transmission, or replaced the rear main seal in the engine, something like that. No other good reason to R&R (remove and reinstall) the transmission.
The "right rear" leak on the engine, that's not common in this engine, it's common in the dual cam (M104) engine, not the M103.
I agree that what is referred to as the "horseshoe gasket" (first time I think I've heard it called that!) could be the problem. They HAVE to use the correct sealant on this job or it won't last long. The PROPER sealant is ONLY Loctite 5900, and the procedures must be followed, especially in terms of cleanliness and cure time of at LEAST 2 hours, I prefer an overnight curing time if possible (do the job in the afternoon and do NOT start engine until the next day). The seal is usually referred to as the "lip seal", also called the cylinder head front cover lip seal. It's not a gasket it's a rubber profile seal.

Depending on miles, etc and how bad the leak actually is, the problem could also be the valve stem seals. Usually a quick spark plug inspection will reveal if these are worn out or not (heavy deposits on the plugs, usually a normal tannish color and may have a "glazed over" look to them. The seals are replaceable without removing the head by using compressed air to pressurize the combustion chambers, then the valve springs can be removed and the seals easily pop off and on.

Gilly

[lino]

Thanks Gilly for that detailed response! I was using the SEARCH button earlier and did some reading about the "lip seal" as you call it and it I think that might be my problem. I will check to confirm as soon as possible.

My car has a little under 120,000 miles on it. I changed the spark plugs approximately 2000 miles ago. The plugs that were in the car looked like new. My mechanic said that they looked like they had 6000 miles on them at most. I changed the oil too and it was clean. I'm using Liqui Moly 10W40. When I went to change the air filter, I found a K&N filter which was also clean. I wonder if my valve stem seals need to be replaced.

I have most of the service records for my car. I am missing some of the last ones and you can see them in this thread. Look at post #12:

http://www.peachparts.com/shopforum/showthread.php?t=96057&highlight=Driven+Plate

[Gilly]

I'll try to look at the service history later. In general the spark plug deposits are the key thing to look for in determining if the valve stem seals are shot. The usual complaint is a poor cold start; it'll do what's called a "false start" in the morning, on the second attempt it'll start right up. Occasionally the complaint is long cranking times to start.

Gilly

[lino]

Originally Posted by Gilly

Yes the "R&R headgasket" means the headgasket was replaced.
Gilly

I just got off the phone with the dealer and the service department guy actually took the time to go through some of the service records with me for the first time. He said that the reason why the head gasket was replaced was, beacuse there was engine oil mixing with coolant - blown head gasket and that when the head gasket was replaced, they didn't change anything inside the engine.

Originally Posted by Gilly

The other one, the R&R Transmission 722.0-722.4 means the transmission was removed. It's all rather cryptic, but I am assuming they may have had to replace a cracked "flex plate", which is what drives the torque converter. Either that or there is more to that work order you're not saying, like they resealed the front pump in the transmission, or replaced the rear main seal in the engine, something like that. No other good reason to R&R (remove and reinstall) the transmission.
Gilly

The reason why this was done was, beacuse where the starter/ring gear connect to the transmission there are teeth and so the transmission had to be removed for the job. (Something like that)

[Gilly]

OK, so I was right about R&R headgasket.
On the R&R transmission, still he's not saying what was done exactly, but IIRC there was something you wrote down about R&R driven plate or something, which would be the flex plate, not the flywheel. YES there are teeth on the flywheel the starter engages in to, but not sure what this has to do with....anything. Especially in regards to replacing the headgasket.

Gilly

[psfred]

If that is brown instead of black, they are normal. However, they should be LIGHT brown to light tan, any hint of black on the center electrode means running somewhat to very rich. You can check that with a duty cycle meter (or plain digital VOM) between pins #3 (red lead) and #2 (black lead, ground) on the diagnostics connector on the left fender -- the one with the round screw-on cap.

If they are oily at all, you have bad valve guides most likely.

Peter

[haasman]

Peter

When one checks the duty cycle:

"check that with a duty cycle meter (or plain digital VOM) between pins #3 (red lead) and #2 (black lead, ground) on the diagnostics connector on the left fender -- the one with the round screw-on cap"

What value should I be seeing?

Haasman

[psfred]

Should be variable around 50% or about 6.5V. Some engines run better at 45% (mine does), usually indicating a need for new injectors (a later project, probably next year).

Fixed means it's running it open loop mode for some reason.

Peter

[lino]

After I repair my car, I will have to consider purchasing a higher quality camera with macro. My camera does not have the macro feature which is useful for taking close-up pictures. I spent hours and this is the best I have.

Photo Session #2 of the Spark Plugs:

Spark Plug 1


Spark Plug 2


Spark Plug 3


Spark Plug 4


Spark Plug 5


Spark Plug 6

[newkid]

Lino,

Great job. My 89 300 ce had the same problem, one drop or two oil leaking around U seal. My friend told me to live with it. I called MB dealer and the service manager told me that was common problem to the older MB. He suggested me to change oil to 20w50. (thicker oil). I did and the leaking stopped.

[lino]

Thanks newkid. Are you still using the 20w50 oil? I use Liqui Moly MoS2 10W40.

[autozen]

Lino,
Please don't post any more pics of head gaskets and valve seals. I think everone here knows what they look like, and they take forever to down load.

Peter