cbereswill

Hi everyone, My name is Chris. First time here so not to sure where I should be posting yet. Anyway I hope someone can help me out here. I just purchased a 1993 Jeep cherokee Country. 4wd a/c if that matters. It had a blown head gasket that turned out to be a cracked head. ( I figured that when I bought it ).
So I bought a reman head from Oreilly'sAuto parts. (7120 head cast) I replaced the head, new water pump,therm-o-stat. everything went really well. 9 hours tear down and rebuild. I started it up and it ran GREAT. Then it started to over heat. I'm not getting water through the head. What did I miss? (i did put antifreeze in it.) 1 gallon in the radiator. I took the stat out and started it again and still no flow. took water pump off to verify I had the correct one. now I'm stumped???? Help please and thanks, sorry so long

cbereswill

Sorry 4.0

BatmanXJ

Could be an air pocket. need to get it full of water without the air. Search for burping the air out.

kjc

The head gasket can be put on upside-down/backwards.. it fits, but blocks one of the main channels if I recall correctly. Also, sealant is required on one of the head bolts that goes thru a water jacket. I think #11 but not sure.

cbereswill

Yes # 11 requires sealant. And only torqued to 100lb. I played with the gasket and seen only 1 possible way to install it.
This morning I am going to put the water pump back on with no stat. Then fill the block through the upper hose. If this doesn't work I guess its shop time.

dave1123

Please be aware the water pumps on the later models with the serpentine belt run in the OPPOSITE direction than the ones with the V-belts. Make sure you have the right one.

The best way I've found to vent all the air from the head is to take the temp guage sender out (on the thermostat housing), fill the radiator until coolant comes out of the hole, reinstall the sender, and finally fill the radiator. This fills the block and head from the bottom.

I would like to recommend buying a PREMIUM pump, one with a metal impeller. On the 4.0, the pump impeller spins only 1/16" away from the #1 cylinder barrel.

Overheating could be the cause for the blown head gasket/cracked head.

cbereswill

Thanks, I removed the stat and filled it from the top hose. Now it is working fine. However it is running @ 210
without a stat. Any other vehicle I have removed the stat from ran around 150. I am going to change the fan clutch today so everything will be new. I know these jeeps read a hotter temp due to sensor location. But I would have thought it would read cooler without the stat. I am starting to think the sensor on the head is useless.

dave1123

This may not be related to your problem, but it's just a piece of information I've gained over the years. We used to race dirt track cars and had a problem with overheating without a thermostat because the coolant was going thru the radiator too fast to give off it's heat. We had to put a restrictor in the thermostat housing to slow it down. Usually just knocking out the center of a thermostat did the trick.

I'm with you though. Most engine won't get above 150* without a thermostat. Your problem may well be the fan clutch. Personally, I never liked a viscous drive fan clutch. They really don't reduce driving force on the engine. It still takes about 25 to 30 hp to drive the water pump and fan.

My dad had a 62 Peugot 404 that had an electric fan clutch like an A/C compressor. When it engaged, the car's performance fell on it's face.