Call the machine shop that did the head and see if they know.

 

Does anybody know if a 4.0 from a late 90's Grand Cherokee will fit in an XJ? There's a ton of those in salvage yards around me

Yeah, I'm thinking why not try!

 

There are a section on this forum somewhere..how to change engines around, what ones fit where, how to identify etc

 

How about a thicker head gasket? They do come difft thicknesses.

 

Stock replacement 53010587AA / Victor Reinz 54249: Compressed thickness 0.043", bore diameter 4.000", compressed volume 8.85cc
Crown Automotive CWA-33007143: Compressed thickness 0.051", bore diameter 4.000", compressed volume 10.50cc
Edelbrock EDL-7348: Compressed thickness 0.042", bore diameter 4.005", compressed volume 8.67cc
Mopar Performance P4529242: Compressed thickness 0.043", bore diameter 3.875", compressed volume 8.31cc
Felpro FEL-530SD: Compressed thickness 0.051", bore diameter 4.000", compressed volume 10.50cc
Felpro FEL-9076PT1: Compressed thickness 0.051", bore diameter 3.875", compressed volume 9.86cc
Felpro FEL-26211PT: Compressed thickness 0.051", bore diameter 3.990", compressed volume 10.45cc
Cometic CGT-C5987-040: Compressed thickness 0.040", bore diameter 3.950", compressed volume 8.03cc
Cometic CGT-C5987-050: Compressed thickness 0.050", bore diameter 3.950", compressed volume 10.04cc
Cometic CGT-C5988-050: Compressed thickness 0.050", bore diameter 4.000", compressed volume 10.30cc
Cometic CGT-C5989-050: Compressed thickness 0.050", bore diameter 4.060", compressed volume 10.61cc
(from here: http://www.jeep4.0performance.4mg.com/tech_specs.html)

And you can get brass gasket-shaped shims, yes. Maybe that's easier/better than worrying about taking off too much. I'm sure there's still a limit though, even with the shims.

 

Still not convinced am buying any of this. OP, ..you said you had the oil tested and they found coolant in it. That means a leak, yet, you say repeatedly no coolant leak, the leak is compression between cylinders, where there is no cooling jacket... due to a warped block, so question, have you cleaned the block of the old gasket thoroughly before checking to see if it is warped? Also, how are you checking to see if it's warped? something not right here

 

It's a working theory. I'm not 100% sure myself!

They found "a little" coolant, not a whole heck of a lot but enough to cause concern, they said. But when I tested compression, testing the cooling system for pressure, looked for combusion gases in the coolant, etc. and didn't find anything wrong.



Here's a pic of the head gasket, you can see the discoloration where the gases where leaking through and heating up the metal



And, yes, I could not detect this with a compression text. Maybe the gap is only large enough when the engine is hot and I'm ******* it real hard ??

 

Just hung up with my machinist, I am having my head done right now on my I6. He said the head was a 'little twisted' and they cut it, but, there was 'no chance' the block is warped. fyi. If you're checking the deck after you clean it up, you need a good $100 machinist straight edge.

 

Hello, what is your head cast #? After looking at your pic, looks like you may have the wrong gasket on your head. Which will be the reason for your overheating. The gasket is blocking sufficient fluid from passing through head. The gasket doesnt have openings for every port opening on your block and head.

 

2+ year old thread bud. Pretty sure whatever the issue was, he has moved on or fixed it.

 

Yeah, I assumed that. But thinking about all those other people reading this thread, and may have the same situation. After changing everything out, antifreeze pressure test, and still over heating? Make sure to have the right head gasket before putting everything back together. The gasket may fit well, but have to make sure all ports are free with the gasket too. Then wouldnt have to worry about overheating and causing damage to head and/or block. Im correcting a Jeep now, that had the same problem from some previous work done.