Is Blow-by ok on 7.3 ?

[jshalala]

On my Super Duty (see sig) at idle when I take the oil fill cap off there is a small amount of steam that blows out of the filler continusly. Someone told me this is fine, others said this is a problem. truck runs great with no problems

[Dave]

A little is perfectly normal.

[Clay Henry]

If you can lay a paper towel over the filler and it blows off, you have excess blowby. Simple test.

[jshalala]

ok ill do that after work. Truck has 264,000 on it but I doubt that it will blow the towel off...we will see. Crossing fingers that it dont.

[Clay Henry]

Make sure its not windy...

[justinlogue5_0]

Originally Posted by Clay Henry

If you can lay a paper towel over the filler and it blows off, you have excess blowby. Simple test.

A paper towel? I heard is was the oil cap. Guess I will have to try the towel now out of curiosity

[jshalala]

Originally Posted by Clay Henry

Make sure its not windy...

O CRAP!!! MY TRUCK IS FRIED! *as the paper towel flies across the road* lol

[ToMang07]

Originally Posted by justinlogue5_0

A paper towel? I heard is was the oil cap. Guess I will have to try the towel now out of curiosity

A ping pong ball is a better test. The cap usually vibrates off, and that freaks people out thinking that it's the blow-by.

[Dave]

Originally Posted by Clay Henry

If you can lay a paper towel over the filler and it blows off, you have excess blowby. Simple test.

not on a 7.3 it will do that right off the showroom floor

Do the oil cap test.

[justinlogue5_0]

Originally Posted by Dave

not on a 7.3 it will do that right off the showroom floor

Do the oil cap test.

Oh thank goodness.