Last march I bought a 1991 190E 2.6 5 speed with 67,000 miles on it. It was advertised as having all the records but when I bought it the owner couldn’t find them (they had just moved) so I know very little about the car. A little afterwards I noticed it used about a quart of oil every 700 miles or so, and a little after that I found this site. After surfing for a while I suspected the valve guide seals. But after changing them the oil consumption was the same. I then checked the compression and all cylinders were within 2 pounds of 184 pounds. The engine runs and starts fine. I had the spark plugs read and they showed some detonation that could be caused by the burning oil. I have some personal frustration because I have a Peugeot Turbo Diesel 5 speed with 260,000 miles on it and it uses abut a quart of oil between changes, and it probably leaks it. So the question is...where is all the oil going? Or maybe it takes a while for the new seals to seal.

My guess is the valve guides. Does it smoke a little when first starting up?

Good luck,

No smoke, even had someone (former mechanic) stand behind the car when I started it.

Could I tell if the guides were loose if I tried to wiggle them with the springs off?

Oil Consumption; 190E
 

I've got a "89 190e with about 82,000 mi. that I bought about a year ago. It too consumes a lot of oil...about 1 qt. every 700 miles or so. I've noticed that oil use is very variable...sometimes I'll go a long time with little use and other times it seems to drop quicker. I also suspect the valve seals or guides, but have not yet had it worked on. I don't see any smoke, and compression is good. No major leaks are evident. I just keep dumping more oil in it.

My guess would be the valve guides. Even though everything seems to be ok, I would want to know where the oil is going. I have 171,000+ miles on my car and it barely uses a drop of oil every 3,000 miles.

I’d like not to guess. Is there something I can do to check them? And my other question was how soon would the new valve guide seals seal?

I’ve also noticed through surfing here that the older M103’s had weak guides but this 1991 had the better ones. YNM? (yes, no, maybe?)

Jim:

Another area to look at is the "top front cover". If you have access to an MB CD-Rom or an M103 engine manual, reference job 01-212 - Removing, installing top front cover.
In between the "front cover at top" and the top of the timing chain cover is a somewhat U-shaped gasket that's notorious for leaking. I loose a qt. every 1500-2000 miles in my M103 motor and a good bit of it is thru here. A veteran parts guy at a local MB dealership told me that M103 motors can loose alot of oil through this area. A local independent mechanic I know who worked at this same dealership for 8 yrs. had the same opinion.

If you change oil the old fashion way, pull the large plastic shroud from the bottom and clean it thoroughly.
Drive for 500 miles or so and pull it. In my case, I've noticed where it's falling from using this approach.

Your engine is a 1991. In a previous post one of the pros
on this site indicated that guides/seals were upgraded sometime in the late 80's...don't remember the exact date.

Just my 2 cents. Regards.


Mike Murrell
'91 300-SEL

After the oil level drops during the 700 miles, does the level continue to drop or does it remain at the 1 quart low level? Seems like there are a number of engines that will consume the better part of a quart after an oil change, then not use any more oil until topped off to the full mark.

If you were leaking this much oil from the upper timing cover, the engine compartment would be absolutely drenched in oil. These covers are a common source of leakage, but it is a VERY minor leak.

Yes, you could wiggle the valves if the guides are that bad. I guess it goes without saying that the piston in that cylinder should be at the top when you do this so that you don't lose the valve into the cylinder.

The seals should take NO time to seal.

Good luck,

I am going to replace the valve seals in my 103 engine in a couple of months. In the mean time, I have been using Valvoline Max-Life, formulated for high milage cars. The oil consumption has dropped from a quart every 1000 to a quart every 1500 miles. This may help.

Still more questions
 

At what point would the oil consumption become excessive and it become a problem.

And when did the new guides come out and do I have them and how long would they last. Also a rough estimate to how long a guide R&R might take?

Oil consumption in a gas engine becomes a real problem when it gets to the point that it fouls spark plugs. If it's not fouling spark plugs, but taking a quart in 700 miles. You are probably getting combustion byproduct contamination in the oil and need to change it often.

If this engine has had faithful oil changes, I'm going to be shocked if it would need anything more than a valve job including guides to do away with the oil consumption problem.

Are you sure of maintenance history and mileage accuracy?

Good luck,

I got a credible explanation for the milage and have no maintance history. It was supposed to have some but the main reason I bought it was cause it was a 5 speed. I use Penzoil Long Life (their diesel oil) 30 weight (I dare anybody with lots of time to ask me why) and I might use the 40 weight come summer to reduce the usage. The plugs look un-fouled but I guess I should keep an eye on them.

O.K. I'm asking Jim
 

Greetings Jim,

I'm curious as to why you're using the Pennzoil? I having nothing against this oil brand, and as a matter of fact I use it in all four on my gasoline engine vehicles. I don't have a bad thing to say about it's use in these engines. I've got 175,000 on one 165,000 on another and 102,00 on the third and the truck is just a baby with only 54,000 Never did have any problems with useage or internal engine problems. I saw it sitting on the shelf when I went in to buy Rotella for my newly acquired MB diesel and just about bought it instead. Actually, on the next go around I just might if you have something good to report that sheds some light on their multigrade oil compared to Rotella. Please tell me your story.

Charles

Please Don't ask me to keep waiting
 

Greetings Jim,

I still want to know the mystery behind the Pennzoil multi-grade oil. I bought enough today to do an oil change, so I'm waiting for good news before I do so.

Tell us more.

Charles