Head Gasket and Head

[TerraWombat]

Wow, I wish I had those machine shop prices in my area. I paid around $360 to have it tanked, fluxed, resurfaced, 3 angle valve job, and new valve stem seals installed (I provided the stem seals, too). I even shopped around and was getting anywhere between $275-$400. I went with the $360 shop because of prior positive experience and their turn-around time was two days.

Did the original head gasket show any signs of premature wear? The back two cylinder may have had coolant in the cylinders because there was still coolant in the head when you pulled it off.

 

[JeepCherokeeGuy99]

Did the original head gasket show any signs of premature wear? The back two cylinder may have had coolant in the cylinders because there was still coolant in the head when you pulled it off.

Suprisingly no. The head gasket wasn't blown. The rear part of the gasket was bent a little but I figured it hapened from me taking the head off. But if your suggesting that coolant entering the cylinder wasn't what was causing the overheating and milky oil then would could have?

 

[TerraWombat]

Only other thing I can think of that would cause the coolant to mix with the oil is a cracked block.

 

[JeepCherokeeGuy99]

Only other thing I can think of that would cause the coolant to mix with the oil is a cracked block.

Well sh*t don't scare me like that! Ha, I checked the block and didn't see any cracks but now that you've got me worried ill check again.

 

[Johnnie Walker]

Might be cheaper to just buy a 4.0L engine.. there are plenty for sale on the forum.

 

[JeepCherokeeGuy99]

Might be cheaper to just buy a 4.0L engine.. there are plenty for sale on the forum.

not with only 117,000miles on them

 

[89Daytona]

Speaking of new head bolts, i couldnt find any the other day. At least not at any of the regular parts suppliers. I probably couldve gone to the chrystler house but didnt.

I got new headbolts for my 89 renix at http://headbolts.com/Jeep-AMC-232-244-258-4.0-engine-head-bolts.html

 

[Wallyman]

I got new headbolts for my 89 renix at http://headbolts.com/Jeep-AMC-232-244-258-4.0-engine-head-bolts.html

Well lookie there. I'll add that to my favorites.

A compression check wouldve given you a lot of help with the diagnosis. Id hate to put an engine back together just to have to take it back apart again.
You had water in the oil, which would be my main concern as opposed to coolant in the cyl. i know they are hand in hand but i usually concentrate on the worst part of the situation. depending on how long that water has been mixed with the oil, you would be better off not worrying about the head and pull the block to replace the bearings and work the bottom end. That's whatll end up causing you the most problems. Take it from a guy who HAS thrown a rod because i didnt want to pull the motor. I did the top-end on an engine before and then lost a connecting rod bearing. Pulling that engine is not that hard and youll have piece of mind especially since you got it from a J/Y. They usually dont have the best reputation for quality cars ya know. Just my thoughts.

 

[gradon]

I've replaced an HG before only to have to take it back off, send it to the machinist for valve job, and replace the rings to get compression back to spec--not fun to redo things. While you have the head off, pour water or gas into the intake and exhaust ports and see if it makes it into the combustion chamber--you'll find out real quick if you need a valve job or need to clean the carbon that's keeping valves from sealing.

 

[Johnnie Walker]

not with only 117,000miles on them

Well lookie there. I'll add that to my favorites.

A compression check wouldve given you a lot of help with the diagnosis. Id hate to put an engine back together just to have to take it back apart again.
You had water in the oil, which would be my main concern as opposed to coolant in the cyl. i know they are hand in hand but i usually concentrate on the worst part of the situation. depending on how long that water has been mixed with the oil, you would be better off not worrying about the head and pull the block to replace the bearings and work the bottom end. That's whatll end up causing you the most problems. Take it from a guy who HAS thrown a rod because i didnt want to pull the motor. I did the top-end on an engine before and then lost a connecting rod bearing. Pulling that engine is not that hard and youll have piece of mind especially since you got it from a J/Y. They usually dont have the best reputation for quality cars ya know. Just my thoughts.

I've replaced an HG before only to have to take it back off, send it to the machinist for valve job, and replace the rings to get compression back to spec--not fun to redo things. While you have the head off, pour water or gas into the intake and exhaust ports and see if it makes it into the combustion chamber--you'll find out real quick if you need a valve job or need to clean the carbon that's keeping valves from sealing.

As pointed out here, low miles doesn't mean anything if you have to tear the engine apart and replace parts. Do it the right way, if you can't afford to do it the first time, how can you afford to do it more than once?

 

[joe_peters]

As pointed out here, low miles doesn't mean anything if you have to tear the engine apart and replace parts. Do it the right way, if you can't afford to do it the first time, how can you afford to do it more than once?

That seems extremely--logical!

 

[JeepCherokeeGuy99]

Got the new head gasket in today and hooked everything back up. Started it up, drove for 50 miles and it runs really good. Thanks for everyone's advice! Maybe in a year or two when he has a steady job he could afford to buy parts for a rebuild but until then he should be fine.

 

[gradon]

good to hear

 

[Talyn]

The back two cylinder may have had coolant in the cylinders because there was still coolant in the head when you pulled it off.

x2. Usually if you have been burning coolant in the cylinder it will be cleaner than the rest. The gasket could have been leaking, you just can't see it. Other than that a cracked head or block. Block is highly unlikely.