oil in coolant

just bought a2001 xj runs great but has oil sludge in coolant ? what do you think head gasket or cracked head :doh:

Google cracked 0331 head and read what you find. Naturally you should do some testing and inspection before you decide what the problem is.

Tim_MN said:

Google cracked 0331 head and read what you find. Naturally you should do some testing and inspection before you decide what the problem is.

Click to expand...

Or it may just be a cooling system sealer additive, like Bars leaks that looks like an oil mess.

Where do you see it?

Seen a few transmission coolers leak internally into the coolant too. Something else to look at.

Start with a simple visual inspection through the oil fill cap. I've seen a few 00-01 engines where you can easily see the coolant coming through the cylinder 3-4 crack right through the oil fill hole.

The 0331 head which came from the factory on all 00-01 XJs can crack between cylinders 3-4. Like Tim said, search if your friend. There are hundreds of threads on this.

Or it could be a simple orange / green coolant mix as well..

Usually when your head is acting up you get coolant in the oil, I would check the trans cooler and the trans loop that goes through the radiator. Also, check your transmission for coolant.

I don't think this is the head.

A cracked head is your most likely suspect. Birchlake is right that you can see the crack through the oil fill hole. I will add a little trick that I learned when my head cracked. Hopefully you haven't pulled the valve cover off or opened the cooling system yet. If the engine is still together, go to AZ and "rent" their cooling system pressure tester. Put that on the radiator and pump it up about 10 PSI. If the head is cracked, you will see a row of little green bubbles coming from the crack. They all seem to crack just in front of cylinder 4.