240D oil usage

I would say that is a sign of valve stem seals are leaking... it is not a big deal... but it is a pain to change them.

If a compression test shows good compression the valve stem seals are suspect. Poor compression is a sign of a worn motor that will burn oil no matter what's done.

When I bought it a compression check was done and it looked great. If the consensus is valve stem I have another question. I live in a small town with a "neighborhood" (But competent) repair shop. There are several places in Seattle and Portland that I can take it that specialize in Mercedes, especially older ones. Is this something that requires specialization or can the local guy do it? He's had some experience with older Mercedes hydraulics so he is up on some of the foibles of this car.

Peter

Are you using diesel grade oil and SAE 15 - 40?

Valve stem seal replacement is a job for someone who has actually done some of these, not a job for someone who says he can do it.

I suggest one should be sure the engine is really clean inside - that the rings are not sticking due to prior lack of oil changes - before plunging into the expense of changing the seals. Be sure the engine runs at 80 degrees F., change the oil a few times.

It starts and runs well so there's no rush.

I'm using Chevron 10-40 for diesel. It' s had oil changes every 3000 miles since I bought it. It runs really cool, about 80, even when low on oil. I'll confess I let it get 3 quarts low before adding and it never got hot. The only sign was that, at idle, the oil pressure dropped a bit. I'm a real novice on diesels. I just know this car is really special and deserves the best treatment. If I can afford it!

*Diesel grade* oil? You're kidding, right? I thought that was a marketing ploy, an excuse to levy a gullibility sur- charge on the credulous. I've heard of it but have never seen it for sale at any of the auto-parts boutiques I frequent.

I've always run 20W-50 Castrol GTX in my 300D, 300CD and

300SDL, and 15W-50 Mobil 1 in my 300D 2.5.

Geoff

Arrrgh!

The cheapest and yet most important treatment you can give it, even cheaper than regular oil changes, is to check the oil level frequently and replenish it promptly if necessary.

Personally, I check the oil in my daily driver (a '91 300D 2.5) twice a week: every weekend and at midweek. And the engine doesn't burn or leak oil; I do that simply as a matter of principle. While I have the hood open, I check the coolant level and the condition of the belts, and give the entire engine a quick once-over. Why not? It's cheap insurance and it takes less than a minute.

Geoff

Diesel grade oil has more detergent in it to keep the soot in suspension. Gas engine don't have this problem so they requirs less...

15W40 regular oil are diesel grade... other can be used as long it does have diesel API rating.

5W40 Mobil 1 is also diesel grade. 15W50 Mobil 1 does not have any diesel rating... Call up Mobil 1 and ask them all the questions you want...

All I remember is that the additive package is very different as diesel has soot problem.

According to the factory nothing should be done until but burns oil greater than one quart every 500 miles. That's their limit.

You need a compression and leak down test. Might be valve guides, bit not be.

How recetnly were the valves adjusted?

Valves were adjusted right when I bought the car. I bought it in Texas ($1500!!!) and put another $1000 into it to get it into the best shape possible for a drive home to Oregon. I figure that it's going through a quart every 800 so if that's ok with the factory it's ok with me. Do you know where I can find specs like that online?

I made an error in an earlier posting. The oil I'm using is 15-40 Chevron for diesels (Or at least they claim it's for diesels)

Thanks!

It's (all) in the factory manual. Most dealers don't have copies in stock any more but they're usually findable on ebay.

I had a similar problem with an 1980 240D with 300k miles. My daughter had it in college and I took her a case of oil from Kmart everytime I went to see her; told her a Qt./week was he cheapest car payment she would ever have. She drove it 3 years that way & was relegious about checking the oil level. Then it was passed on to my son., He came home one weekend and told me the oil problem was cured; he had just driven it 400 miles on a fraternity trip and it did not use any oil.

Three weeks later I gave it the Salvaion Army because he #4 piston had a hole in it.

If it had stayed with my daughter, it would probably still be running @

400k.

Remember with a diesel, oild being burnt is just part of the fuel mixture. No plugs to foul.

Just my thoughts. the 240D was a great car.

Tom D.

I had a similar problem with an 1980 240D with 300k miles. My daughter had it in college and I took her a case of oil from Kmart everytime I went to see her; told her a Qt./week was he cheapest car payment she would ever have. She drove it 3 years that way & was relegious about checking the oil level. Then it was passed on to my son., He came home one weekend and told me the oil problem was cured; he had just driven it 400 miles on a fraternity trip and it did not use any oil.

Three weeks later I gave it the Salvaion Army because he #4 piston had a hole in it.

If it had stayed with my daughter, it would probably still be running @

400k.

Remember with a diesel, oild being burnt is just part of the fuel mixture. No plugs to foul.

Just my thoughts. the 240D was a great car.