Hello
 

hey i got a 12 valve cummins and when i go over 1800 rpm it blows all the oil out,from the over flow tube just wondering if the motor neeeds rebuilding or something else is wrong???maybe something to do with vaccuum ??? I dont no hope somebody Knows Thanks

Do you have any vapor coming out of the tube when it's running at idle?

Very little.If i run the truck over 1800 for an extended period i will lose all oil out the vent tube.

hmmm not good. hows the truck run. how many miles on truck or any other info you know about the truck would definately be helpful

It has 280,000 Kms on it runs really good.Does not go through any oil at all except when run over 1800 rpms.

You say you loose ALL your oil out the blowby?? Or is it just a little bit? i've seen this a lot with higher mileage engines. I've seen them run forever with this condition and not having any problems with loss of power or anything. best thing to do is buy the vavle cover mounted vent set up and remove/plug the breather in the timing cover. most of it has to do with the rpms and not the blowby at all, at high rpms your front gears are spinning like crazy, throwing oil everywhere and right out that hole in the timing cover. if you want a really cheap fix- strap a water bottle to the end of the tube, let the tube go in a little cut a small hole in the top of the bottle above the tube and it will catch the oil. but you gotta empty the bottle often.