Alright, I'm officially at my wits end. I have an 87 cherokee and had been having problem overheating. Here's a list of what I have done:
new CSF radiator because it the old one was bone stock
new waterpump because I have the autozone lifetime warranty and was free
new factory 195 thermostat
new fan clutch. Not sure the old one was bad but was also bone stock, so wth
new hoses because old ones also stock and really needed them anyway
new bottle and cap
new heater control valve because I broke the old one when replacing the hoses
Before changing the above I drained the system, filled with straight vinegar, ran for
a day and then flushed, filled, ran for awhile several times until entirely clear.
I also flushed the heater core per the link I found on here previously.
Refilled with 50/50, burped the system with the nose parked downhill and removing temp sensor. Runs fine for awhile but after getting on the highway, the coolant would expand to the point that it filled the bottle full and then would pop the cap loose and overheat.
Finally got tired of this, went to the boneyard and got a bottle and cap from a Dodge Intrepid. Was an easy fit with an adapter or two. Now instead of popping the cap and overheating, it fills the bottle full and then starts pushing it out the overflow line and continues this for as long as you run it. Won't overheat from this until you have lost too much coolant. Here's the wierd thing, and I remembered it doing this on the XJ bottle too: after shut down and cooling off even over night, the coolant never returns to the block, radiator, ect. If I park it nose down hill and remove the temp sensor, the coolant will drain out of the bottle and I can fill the system to the proper level. Why do you think the coolant won't contract and return back to the block, rad, hose,etc?
I haven't had time yet to take it to a rad shop and get the coolant sniffed to check for HC but does this sound like a possible head or head gasket problem? I can't understand why the coolant is "backing up" in the bottle and not returning to the block.
Any ideas?
new CSF radiator because it the old one was bone stock
new waterpump because I have the autozone lifetime warranty and was free
new factory 195 thermostat
new fan clutch. Not sure the old one was bad but was also bone stock, so wth
new hoses because old ones also stock and really needed them anyway
new bottle and cap
new heater control valve because I broke the old one when replacing the hoses
Before changing the above I drained the system, filled with straight vinegar, ran for
a day and then flushed, filled, ran for awhile several times until entirely clear.
I also flushed the heater core per the link I found on here previously.
Refilled with 50/50, burped the system with the nose parked downhill and removing temp sensor. Runs fine for awhile but after getting on the highway, the coolant would expand to the point that it filled the bottle full and then would pop the cap loose and overheat.
Finally got tired of this, went to the boneyard and got a bottle and cap from a Dodge Intrepid. Was an easy fit with an adapter or two. Now instead of popping the cap and overheating, it fills the bottle full and then starts pushing it out the overflow line and continues this for as long as you run it. Won't overheat from this until you have lost too much coolant. Here's the wierd thing, and I remembered it doing this on the XJ bottle too: after shut down and cooling off even over night, the coolant never returns to the block, radiator, ect. If I park it nose down hill and remove the temp sensor, the coolant will drain out of the bottle and I can fill the system to the proper level. Why do you think the coolant won't contract and return back to the block, rad, hose,etc?
I haven't had time yet to take it to a rad shop and get the coolant sniffed to check for HC but does this sound like a possible head or head gasket problem? I can't understand why the coolant is "backing up" in the bottle and not returning to the block.
Any ideas?