metzy25

Hey guys this is my first time posting here but I'm hoping you guys can help me out! I have a 2000 jeep grand Cherokee limited 4.7 that has a white milky substance on the oil cap, but there's none on the dip stick(just regular oil), there's no lose of engine poor, no white smoke, and no over heating. I purchased the jeep yesterday and drove an hour back home perfectly fine,
There wasn't a milky substance on the cap when we left, the oil was very light.
Do you guys know if I have a blown head gasket or what the problem may be? Thanks for the help!

ripp6957

Mine has the same issue. I'm not using losing any coolant and it runs great. When I change the oil, it looks fine. Now I just bought another 4.7, same year, that overheated and blew the head gasket. That oil looked TERRIBLE, and ran poorly. The water resevoir would bubble as soon as you started it, so it appears that a blown gasket is easy to diagnose. On that one, I swapped in a junk yard motor. Good luck!

Bustedback

It may have been driven only for short trips and never getting fully warmed up. Change the oil and filter, clean the smagma off of the oil cap and drive the **** out of it. Keep an eye on it and make sure you get the engine up to temp as much as you can.

metzy25

What I've read online it seems like condensation? Due to cold weather, does that sound right? I also read that it's common in the 4.7.

dave1123

Yes, this is quite common with any engine that isn't driven far enough to vaporize whatever moisture comes in with the air as the engine cools. SAE says drive a minimum of 15 miles after the engine reaches operating temp to fully evaporate this moisture. Cold, wet climates are the worst for this. Also replace your PCV valve to get the maximum airflow thru the motor. Short trips to the grocery store, etc, cause a buildup of this white condensation and will eventually turn black called sludge.

If you make a lot of short trips, you should drive about an hour once a week to help keep your engine clean.