My Jeep has been going though a couple gallons of coolant for the last month or so and every time I have checked the oil and the coolant in the radiator it never appeared milky or different. Well last night I was waiting in the line at the drive though at McDonalds and all of a sudden my heat gage started beeping at me so I pulled out of line and parked my Jeep for a while. Well today I pop the cap off radiator and look inside to see brown oil floating on top of the coolant like its the Gulf of Mexico. I know a guy who will pressure test the block and do what ever to diagnose the problem for $25. I just bought this Jeep back in September and they guy gave me all the receipts he had for it and he just put a new head on March 2009.

At this point signs are pointing to a bad head gasket due to the oil in the radiator. I was quoted $1,700 and $925 for a replacement head and gasket from two shops here in town. I have no idea if that is a good price or not.

The other option I am currently looking at is a possibly replacing the whole engine. When I bought the Jeep the guy threw in a spare motor that he had laying around. Supposedly its from a 1999 or a 2000 and it would be going into a 1998 Cherokee. Would it be cheaper to possibly replace the motor as long as the cylinder compression checks out on each cylinder? To my knowledge I do have all the tools to do the swap and the neighbour has a hoist.. What else should I check out on the other engine before making my decision.

 

Nobody has any sort of advice?

 

did the guy that sold you the xj say the motor was good he gave you

 

Dude, yea, deff getting oil in your coolant, not good! I would say head gasket

Buy the Chilton repair guide and do it yourself for 99% off!

 

if it is agood motor pull the head off it havit cleaned and valve job done put it on your self keep the one you takoff for spare lot less work than pulling motor and lot cheaper than the other guy doing it

 

If you can swap a motor, you can definitely change a head gasket.
Since this appears to be the second head gasket in about a year and a half, I would pull the head and bring it to a machine shop to be checked and resurfaced. Replace the head bolts too, as they may have exceeded their stretch-limit. I would personally do this before swapping the engine with one that you know nothing about. You could always pull the head from the spare engine if it turns out there is something wrong with your current one. Buy a quality head gasket. The difference between a $20 head gasket and a $50 gasket can be the difference between doing it twice. There is one head bolt that requires sealant to be applied to it when installing. Pay attention to that too...

 

I was told that the spare motor was more or less good. I thought the guy told me that the engine was starting to have oil pressure problems. Of course my current engine has "problems" with that as well with the gauge indicated that there was 0 oil pressure at idle but when driving it was fine. Which is a very common issue from what I have read.

Now at the one garage the guy was saying that if you are going to be redoing the head you might as well as redo the entire engine as the bottom half shouldn't be far behind due to the differences between the older lower block and the new head. That was the only reason I was sort of leaning twards putting the other engine in if that was in fact true.

 

if you trust the prev owners word that it runs do it

 

If you do swap the engines, there is never a better time to install things like new oil pump and head gasket than when the engine is not in the jeep. Oil pumps are cheap. Change it - especialy if you have doubts about oil pressure...

 

Alright got the Chiltons manual and it looks like I will have no problem swapping stuff out. I know if I get a new head it will have to be machined. But, I was talking with my dad and he mentioned that the surface of the block might need machining. What is the likely hood of the surface on the block where the block and head meet need machining? Could a machine shop do the work with the block in the Jeep if need be?

Thank you for all the great advice so far.

 

its a cast iron block its very un likely is warped xj are famous for small hair liune cracks in the head if they get over heated bad just clean the top surface of the block and check it out good and you should be allright

 

I would have the head checked out. I don not believe it's possible to plane the block with it still in the jeep, and even if you can, metal shavings in everything would cause problems.
Pop the head off and see if you can see where the gasket blew. I would say between cylinders 3 and 4, it's the weakest point. If you can easily say it was the gasket, have the head checked out and a valve job, etc done. Then buy a good gasket and put it back together. Do not go cheap on head gaskets or you'll be doing it again real soon.
Not sure what year they started distributerless ignitions, but swapping a 99 or 2000, it would depend on whether either is distributerless or not. If you trust the engine, swap it.

 

Well to update you guys I took the XJ to a guy my dad knows who owns a shop. I figure its worth $25 to see whats going on with it before I tear into it and after pressure testing every thing the head and gasket was just fine. Apparently he pressure tested the radiator and it turns out that it is the transmission cooler lines blew on the pressure side.

Judging from the receipts I got from the previous owner he bought a new radiator in March 2009 and it was faulty and replaced again in December 2009 under warranty. I hope 3rd time is a charm.

Thank you for all the great and accurate info I will remember it for the day where I actually will have to change the head.