Recently I've noticed that whenever I check my oil there is a thicker whiteish substance just on the very bottom of the dipstick. (Maybe the first 1/3" or so) but the rest of the oil on the stick above that point is fine looking. I know that milky white oil is a sign of a possible head gasket leak or coolant in the oil but if that was the case wouldnt all the oil be off color? Or does it settle to the bottom?

PS: I've changed the head gasket before so can do it again with no problem but if I do I want to change the head. Are 4.0 XJ heads interchangeable up to the model end in 2001? I have a '94.

 

*How many miles on this oil?

*Does this vehicle take primarily SHORT trips or LONG trips?

*Has this engine ever been overheated? (this can lead to a head gasket or a head issue)

Condensation can develop which is not an internal problem. Answering the above questions can be helpful in sorting this out. Long trips can burn off any condensation that builds up in the crank case.

 

Sounds like you have anti-freeze in your oil

 

i just had that same problem and it turned out to be my head gasket .. so good luck

 

it sounds like you have a condensation problem... you need to take a very long drive... well change your oil and take a very long drive...

 

*How many miles on this oil?

Can't say for sure. I was having a problem with oil leaking out my valve cover for awhile so was adding about a quart a week for a long time so it was getting replenished.

*Does this vehicle take primarily SHORT trips or LONG trips?

Short trips only during the week. City driving. Long weekend trips of up to 150-200 miles at highway speed.

*Has this engine ever been overheated? (this can lead to a head gasket or a head issue)

Overheated last summer when my drivebelt broke and I didn't notice it until the lights came on and my power steering was gone. But only drove it about 1/2 mile afterwards to get it parked and it's run fine since.

I'll try a complete actual oil change this weekend or one night this week and see if it comes back.

 

So as I've been pondering it..The front valve cover breather tube elbow snapped off my engine last fall and now is just a small stack sticking up venting whatever instead of having the tube run over to the air cleaner box. Could this be a source for condensation to get in and mix with the oil?

 

Definitely resolve this, whether or NOT it is involved. It is important to the efficiency of your engine.

Get new CCV (crankcase ventilation) grommets and tubes and a valve cover gasket. Remove valve cover, thoroughly clean the inside of the valve cover and install new grommets, re-install valve cover, new CCV tubes and you're good to go. The CCV hardware is only around $45.