Well yesterday I bought a 89xj for $500 dollars to go along with my 97xj. The motor has 240k miles on it, when i checked the oil yesterday before I bought it was a little yellow but did not think to much of it, so today I drove it around town for awhile and it ran great, it did not over heat, or smoke or anything like that. So when I got home I decided to check the oil again and to my surprise it's milky but, mostly on the tip, my coolant don't look like it has oil in there but I could be mistaking. If anybody has any Ideas to help me out please let me know, thanks.

 

I would just keep an eye on your coolant,if you start loosing coolant then there are some other test you can do to find the problem.

 

Should I try to change the oil?

 

yes ! i deff would considering you just bought it , who knows what kind of maintance the previous owner kept up with , i would change the coolant too and keep an eye on everything

 

I would,just because you know what you have,when they set for anytime they can get moisture in them. I have had moisture on the dipstick before that appears to be milky,but no evidense of a leak, when you change it look for water as soon as you remove the plug. Let it set overnight before you change it.

 

When I change it, what if there is water right when I remove the plug, what does that mean? Also thanks guys for all the advice! It's greatly appreciated

 

definately change the oil as well as all the other fluids. it's not uncommon for moisture to accumulate if it sat for any length of time. think of it like a soda can or a glass on a table. they sweat moisture right out of the air. your crank case, trans, axles, T/C and fuel tank will do the same thing but on the inside. when you drive it regularly it will heat up those compartments (minus the fuel tank) and keep the moisture out.

 

You should not see any visible water. If there is it will be the first liquid you see.

 

Well this morning I went to change everything out, I found milky substance in the air filter, and alot of oil in the carb. Further examination I seen leaking where the block and the head meet I assume that's where they meet, but when I got it I did not see any leaking. I'm a dealing with a blown head gasket? Could it be something else? The truck does run great! I took some pics of what I seen.

 

After servicing you might have some one pressure check radiator and water system. I usually pump system up and leave under pressure over night for leakage. high mileage of 4.0 is not bad if engine has not been excessive overheated.

 

X2 to pressure testing the cooling system. You can "rent" the tools at any of the quicky auto part stores.

 

Check your PVC system

 

x2 This will allow the water to separate from the oil.

Having oil (milky or not) is a sign of a problem in your PVC system. IMO it sounds like a broken head gasket or cracked block. Especially if you are getting the milky stuff in your filter.

 

just to be safe i would run some head gasket repair through it. that might stop it

 

Well I just got done changing the oil, air filter, coolant, and cleaned out the carb. I took it for about a 20 mile ride and it seems to be alright. I don't see any milky stuff on the dipstick, but yet again I just changed the oil. Thanks everybody for the advice. Hopefully this will be it, but if not I probably do have a blown head gasket.