Blowby on my diesel.
 

I have an 82 300D turbo diesel, with only 87,ooo miles on it. The other day, I opened the oil cap while it was running and I noticed there was a small amount of blowby comming from the cap. Im new to diesel cars in general, but is this anything to worry about, and Is there any way to correct it?

Thanks everyone-
Matt

If it starts easily, especially in the cold, don’t worry about it.

I don't understand how I have such good compression (385psi) but still seems like I have more than normal blowby when you pull the oil cap. I thought the two are directly related.

I remember watching a video on diesegiant.com where he removes the oil cap.

http://dieselgiant.com/Mercedes%20blowby%20test.wmv

Why would you be concerned with blowby?

The symptom is usually worthless for evaluating the engine unless it's also coupled with other symptoms that lead to a conclusion of worn rings and/or valves.

There is absolutely nothing you can do about blowby short of rebuilding the engine.

They are indirectly related. Other things like valve stem seals can also cause blow by.

I was a little concerned, considering it is my 1st car and im only 17. Would Adjusting the valves help any bit? Yes, it starts fine in cold conditions. Should I re direct the tube that goes to the air filter, to say the side of the motor, so Im not putting garbage into my intake?


Thanks again-

Matt

Nothing can be done to reduce blowby short of rebuilding the engine.

Leave the tube exactly where it is. The "garbage" is oil fumes that are readily consumed by the diesel (oil burning) engine.

Please remember,
Very highly paid German engineers spent a lot of time on these engines, and probably have very good reasons why the did things a certain way.
Just a thought........

Jimmy.........OMG..........Tom Walgamuth hijacked your account..........:eek:

I knew he sounded smart sometimes.......;)

How are they indirectly related? Blowby is caused by air leaking around the rings or valves. Right? So checking the compression tells how much pressure is leaking around the rings and valves too. How do valve stems cause blowby? Does it have to leak past the valve first to get by the valve stem?

I believe i read somewhere that the vacuum pump let out into the crankcase? so that a vacuum leak could look like blowby?