I have a 2004 ram 2500 hemi that keeps blowing the oil cap off. I replaced the pcv valve and still the same thing. The truck has 330000 miles on it so I thought maybe its worn out and too much blow by so last week I installed a remanufactured engine and even with the new motor it still blows the oil cap off. Ive bought 4 different caps trying to see if the cap was the problem also. Any help would be appreciated.

 

A new motor shouldn't be doing that. Do you still have excessive crank case pressure? (apparently....) Gotta be a reason for that. Even with PCV disabled, it shouldn't be blowing that cap off.

 

Its baffling to me too.

 

Well, since you have had two motors doing the same thing, is there anything hooked up to it that could be pressurizing the crank case??

 

I know you have a new motor, but I'd do a cylinder compression test and probably pull the valve covers off. Sounds like combustion entering the crankcase for that much pressure to be there.

 

no the motor is stock.

 

I know a compression check is the common sense thing to do it just puzzles me with 2 motors one of which is new doing the same thing. No other symptoms. Truck runs perfect and no codes either. Gas milage is around 15 on average.

 

Pressure is coming from somewhere....... Need to find out where.

 

I know just don't know where. The only common part on the 2 motors is the intake. I didn't reuse anything else off the old motor on the new one. Is it possible for that to cause it? I don't see how but maybe someone here knows something I dont.

 

The intake can't generate pressure. Unless you have forced induction.

The only way I can see that much pressure building in the crankcase, would be VERY bad rings. I wouldn't expect that from a rebuilt motor......