I have a 2000 durango with around 116000 miles. I have had it since april of 07. bought it with 106 thousand. Engine runs great other than the #3 injector that died... so it runs rough.. so i gotta replace that. but my question is.. in the oil fill cap i get a whitish foam all over.. the oil it self looks ok.. even after an oil change.. if you clean out the oil fill tube within a few miles the foam is back.. i would think it would be coolant or water vapor somehow getting in the crankcase.. the pressure test seems to stay up on the cooling system.. any other ideas what this might be or how to deal with it? thanks

 

71gp:


Do not spend any more effort being concerned about the foam in your filler cap. I presume you have the 4.7 motor, and this is called "emulsion" by DC. It is caused by the fact that the oil filler cap/tube is plastic, and is cooler than the engine itself, therefore condensation occurs there.

On the other hand, I would be quite concerned about the engine miss you are having. When a cylinder does not fire, besides a power loss the fuel sent in does not burn. Instead, it washes down the cylinder removing any oil there to lubricate the piston rings thus increasing wear. There is also a potential for damage to the catalytic convertors because they don't like seeing unburned fuel.

I guess if the injector is not working at all, these comments might not apply, but I know that the engine miss would drive me nuts and I could not stand to drive it that way.

Don

 

Don't drive it until you fix the injector issue. When your engine is running and gets around to #3 and doesn't fire the next cylinder firingputs extra stress on the crankshaft and can break the crankshaft.

 

i agree with mean green.. Park it..

 

Whitish foam on the oil cap ?

Every time I see this it is bad rings.

Seems the compression blows past the rings (blow-by) and down into the crankcase.
Then it blows through the PCV.

1.) Pull the oil cap off and look for white smoke blowing out your valve cover.

2.) Do compression check.

3.) Check your PCV, Air filter, are they caked with whitish foam ? or are they normal black ?

dj

 

If you don't drive far to work, or whereever.. the White Foam usually builds from the oil not being able to get up to operating temperature for a long enough time.

 

I was worried about the same thing you were when I first got mine, but as most people posting have said it is condensation caused by the moisture buildup, you should see it start disappearing in late March or when weather gets warmer. Just keep on top of it, and clean it out evey so often,if you have doubts, check the condition of the oil itself on the dipstick, as long as that is normal then you should be fine.