400e burning oil

[sunman]

I just got a 1992 400e and noticed after my oil change, 1/2 quart is missing in 500 miles. I checked all the plugs. the first 2 plugs on the passanger side towards radiator have a little oil on them at the threads. The tip is dry. I assume that is the famous donut washer replacement. I did not see any leaks. The car has 162,000 miles and I doubt the valve seals were ever done. I am not sure if there is anyway of finding out either. I don't get the ticking noise from the valve guides either. Where is my oil going?

[Larry Delor]

Mine seems to want to "use" half a quart, and then decide to cut way back on its habit. Monitor it for now - see if it uses any more from this point on.

[deanyel]

I'd change the valve cover gaskets including the donuts, then monitor it. Not likely you have a valve seal problem.

[400E]

Like Larry said, many MB engines seem not to like to be kept at the "full" mark on the dipstick, so if you've been trying to keep it full, you may experience, as Larry and I among others have, that the engine will "use" more oil until it finds the level it seems to like, which is usually at the halfway mark. On mine, this has happened every time I've topped it off to the full mark, and once it gets down to halfway to the add mark, it's fine until the next oil change. On the other hand, since I've been filling it only to the halfway mark at oil changes, no significant oil usage in 5000 miles between changes.

[sunman]

I added 8.5 quarts of oil which made it to the full mark. I made sure it was not over this mark. I am going to monitor it in a few days. I'll let it come down if it's going to and keep an eye on it. Hopefully it will level out like you said. I am not sure what the previous owner was using but I am using synthetic 5w40. There was a few drops of oil in 2 cylinder plug sockets (probably from the donut washers). Plugs are all dry at the tips (thankfully!) I'll post in a few days.

[sunman]

I have driven 200 miles after topping the car to the max line and checked the oil today. The oil level is slightly below the half mark. I checked for leaks and did not find any. That is quite a bit of oil for just 200 miles. What gives? My exhause does not seem oily either. Just black. Any suggestions? Should I wait and hope it levels out somewhere?

[ebennz]

the m-119 was plagued by leaks.

you're losing oil from the back of the right valve cover gasket [maybe left side as well], and from both sides of your front timing cover.

also you maybe made a mistake by switching to synthetic oil...it seem to find places to leak that dino never thought.
i'd use the 50w synthetic in the summer months, the 400e's could not dispate heat very well. also 1 of the reasons ALL w124 m-119 wirng harness degrade

[400E]

Originally Posted by sunman

I have driven 200 miles after topping the car to the max line and checked the oil today. The oil level is slightly below the half mark. I checked for leaks and did not find any. That is quite a bit of oil for just 200 miles. What gives? My exhause does not seem oily either. Just black. Any suggestions? Should I wait and hope it levels out somewhere?

Just sit tight and monitor over the next few weeks. If it keeps dropping, you do probably have a leak. If it stays the same, then you know how "full" to fill it next time.

[ebennz]

pull the splash pan.

see what it indicates, and start there.

i'd suggest you clean it and then watch it.

what does the coolant look like?

it should be easy to see if your front upper timing cover is leaking.

[sunman]

Coolant is very clean. No problems there. I am going to pull the splash sheild and check there. I was thinking of changing to the 15w50 weight oil for summer and changing to 0w-40 in winter. I did notice a little bit of grease on the drivers side cylinder bank towards the firewall underneath. Perhaps a valve cover leak? I will try and take some pictures and post them.