jakeclkdude

I've had my car for 3 1/2 years now and I have 45,000 miles on it (I bought it new). During the last three months, my check oil level warning came on twice and I have added 3 quarts. I have not noticed any smoke coming out of my exhaust and there aren't any oil stains on my driveway. On the otherhand, due to a change in jobs, my commute has increased and I have been driving significantly faster (more interstate driving). Should I be concerned? Where is the oil going?

Mike T.

How far do you drive in a month?

Driving at high engine speeds will often make an engine consume a fair bit more oil than driving at a lower engine speed would.

second question:

There may be no oil stains on the driveway, but is the underside of the engine moist in any location? Some leaks happen at speed and are in locations where static oil dripping is minimal.

Oil consumption of under 0.5 L/1000 km (~1/2 quart per 600 miles) is nothing to be too concerned about.

If the warranty is still active, have the dealer properly conduct an oil consumption test. Otherwise, if the consumption is lower than I noted above, keep recording it to note any trends, but don't worry in the meantime.

My 180,000 mile Peugeot 405 drinks between 0.2 and 0.38 L/1000 km and has from day one. It's still going strong, 14 years on.

mleskovar

Doing the math...that's roughly a quart every 1000 miles. That's excessive...but a dealer wouldn't say it was excessive if under warranty. If this usage just started...like it appears...then I would look for a leak. Unless you are driving 100mph+ then speed isn't an issue. I'm curious, what type of oil are you using? Synthetic? Sticking to FSS schedules?

jakeclkdude

I'm using whatever oil the dealer uses and I have been very faithfull with my FSS. The three additional quarts that I've added were Shell and Penzoil (the only choices I had at the gas station). My interstate cruising speed is usually in the 75-85 range, with an occassional sprint at 100. I'm going to inspect for a leak.

mleskovar

I hope you are not mixing fossil with synthetic oil. Usually synthetic is not available at gas stations. Is the dealer using fossil or synthetic?

bamberger_1

Oil comsuption around 1.5 to 2 quarts per 1000 miles is a value which is considered by MB as "normal". My opinion is that for older higher milage cars this may be true. For a 45kmls it seems on the high side ( I would accept at highway driving about 0.5-1 qrt per 1000 miles).
Not seeing anything on the floor of the garage is clear since most of the engines have a alomost fully covered bottom. The oil, if leaking, is dripping into the cover, and most of it is just flying of during fast driving. The other option is burning the oil, which is not always so hefty that you would notice the blue smoke in the rear view mirror.
What you can do to check whether the oil is burnt or just leaked is the following. Take of the bottom plastic cover, clean the engine thouroughly with engine cleaner or brake clean, spry on talkum power (or a special leak search agent) and go on the highway for a, say 50-80 miles, spin, (during dry weather) and than check whether oil has leaked some where and gathered in the talkum or what ever you used. If you can see anything, then most probably the oil has been burnt in the cylinders.
If this appears to be the case check the spark plugs whether they are fouled, which may just call for new valve stem seals. If this is not the case has the compression checked to find out the pressure loss beteen the piston rings and the cylinder walls, than you know, and at 45,000 miles both cases may call for warranty claims against the dealer.

jakeclkdude

Just heard from the dealer. They are taking my engine apart to assess the problem. One thing I found a little disturbing, the service rep made reference to the way I drive the car and that he knew this by hooking up the computer to my engine. What would the computer be able to tell him?

Update to follow.

bamberger_1

I guess someone tries to scare you to sneak out of possible warranty. My opinion in this case BS.
The computer shows basically the readings of the fault indications over a periode of time, which you also see poping up in the instrument cluster when the problems acure.
He may also see a little more detailled messages concerning the individual fault indicated to help him fix it.
He will NOT find out when and for how long you were driving around with your girlfriend and for how long you were sitting in the park or her parking lot, he will also not see what the alcohol level was at that time ;-)) I'm sorry hope you can stand some humor, dont worry about his comments, cars are there to be driven!!!!!!! Stay cool! These MB-cars are made for German Autobahn driving and 100 mph is nothing compared to a normal Áutobahn speed in Germany and the cars have no problem to deal with that.

jakeclkdude

it's a good thing he can't tell about my girlfriend . . what if he were to tell my wife?

jakeclkdude

Okay, to bring closure to my saga, the dealer found scoring on the wall of cylinder #5, which was apparently the cause of the oil consumption. Fortunately, the car is still under warranty (with only 5,000 miles to go, and the dealer replaced my engine blcok and pistons. According to the service representative, had my car not been under warranty this problem would have cost me $8-9,000.

Nektopoli

If your car has FSS it might be cover for 10yr/150,000 miles.

NP
Cool, I cover'ed also.

pocholin

Something is not right there, my previous car (Chevy Impala SS 96) would use about 1 quarter every 5000 miles, the E55 doesn't burn any oil in 14,000 miles.

Also make sure you don't mix oils, ask your service advisor what oil you are using, an have him check on the oil consumption, your car shouldn't burn that much oil.

pocholin

Oops, I just read this post :o :o