1981 240D Blowby Question
 

I have a 1981 240D Manual transmission with 207,000 miles on it. The car is great, San Diego Rust Free car, everything works, including complet vacuum system. I read the threads on here about blowby, and checked my car out. I did a blowby check when the engine was cold and hot, and both times I had a good amount of blowby. I loosened the oil cap, and it would sit there and shake. The strange thing is, my car runs excellent. I have owned a couple of 240D's and its power is better than the others. Its 0-60 time is right there with the factory specs. So my question is, how important is this blowby issue. Is it a warning sig of things to come in the furure. Should I just leave well enough alone. Thanks

do you have any smoke out your exhaust while driving?

The car never smokes at all, not even when I start it on a cold morning.

If the power is good, the oil consumption within factory specs, why worry:confused:
My '77 240 has a good amount of blow-by with 143,000mi but it runs good, uses maybe a quart of oil in 2,000mi. I would get in it tomorrow and take a 1,000mi trip.
How many 30 year old cars could you say that to???

As long as it starts and runs fine don't worry.

22 seconds? :D

I think blowby is a relative thing not easily measured. Intake manifold on my '79 240D is always wet with oil. I consider it something that adds to longevity, oil fumes drawn into the intake.

Mecedes has a tool for measureing blowby.
I would ignore blowby until you have some other complaint about the car...
There is a long and funny thread in the archives about trying to compare blowby by using a large garbage bag held to the valve cover hole...

http://www.peachparts.com/shopforum/showthread.php?t=118532&highlight=blowby

Thank you for all of the responses, I guess it is just another characteristic of my car. I can definately live with it.

I wouldn't worry about it! Any engine will have some blow-by and Mercedes Benz has the spent air from the vaccuum pump discharged into the engine! Since you have no smoke and performance seems to be fine, just keep your engine oil changed and have your valves adjusted regularly and you should be just fine!

my 240D has 711,500mi on it and it has considerable blowby. when i put the cap on it loosely it dances around enough where it falls off the valve cover. it does also smoke somewhat, and oil consumption is about 2 quarts every oilchange.(i add it during that time). the car drives great and i have no complaints.

my 300D is much better. it is not my beater first of all and it has 182,000mi on it. the blowby is almost not mearsureable. the cap does not move at all when i loosen it, and it does not smoke or use oil.

what you described as having blowby is not much at all in my book, and i think your car is just fine. enjoy it.

I've never seen people so paranoid about blowby as MB diesel owners.

Yes, mine has some too. Quite a bit acutally. Since she can still get over 100 mph and can start without glow plugs, I'm not concerned!!

Isn't there some kind of oil you can add that bonds to the cylinder wall and the piston ring that reduces blowby? I remember reading that somewhere.