Overheating problems

[xjkraut]

I put a new waterpump and thermostat in my cherokee, the truck runs fine around town, but when i get on the highway it runs really hot but never overheats, thinking about puting a new aftermarket temp gauge in. some one please help me.

 

[xj88superjeep]

If overheating on highway only, double check your coolant level first! If the level is low, then you have a leak causing the problem. Otherwise, This is a heat transfer issue due either air restriction in the rad fins or coolant flow restriction probably in the rad, but on the cherokee could indicate a bad head gasket or cracked head. Before panicking about the head though, check the condition of the radiator itself. If it is old and crusty with missing fins, you gotta replace it. If it is caked in mud, clean out the fins (with a garden hose, not high pressure) like ten times. If the rad is old, it could be corroded and scaling/clogging on the inside. Check all these things, and get a rad flush. Keep in mind, could need a new rad, could need new head gasket or head.

 

[xjkraut]

I replaced a leaking waterpump, but didn't have the problem before, only after I put the waterpump and thermostat did in run hot. no leaks and the system is full.

 

[xjkraut]

I bought a ASC pump from advance autoparts, am i worried about not having enough flow, or a crappy pump?

 

[menos]

What year truck? Open or closed cooling system? Are you sure the system is burped (all of the air removed)?

 

[xj88superjeep]

What year truck? Open or closed cooling system? Are you sure the system is burped (all of the air removed)?

x2...

did you replace the t-stat? If you did did you get one with the "jiggle valve" (i think that's what it's called) to let the air escape? If not , you may have to "burp" it. I found that mine self burps after driving a few miles, but that's not the case with every xj. So you may have air trapped in the system, and this will definitely cause poor cooling.

 

[xjkraut]

1995 cherokee sport. do you have any recomendations on burping, i know jeeps are notorious for having this problem. i filled the system on a hill, let it run with the cap in the first position, and turned heat on. anything else?

 

[menos]

Did you flush the system when you had the wp out? It's possible you dislodged some crude and you now have a restriction in you radiator.

 

[REPOXP777]

Park the jeep with the front of the vehicle facing down (like in a ditch) and pull the temp sensor at the back of the head to let the air escape .

 

[.40CalPatriot]

1995 cherokee sport. do you have any recomendations on burping, i know jeeps are notorious for having this problem. i filled the system on a hill, let it run with the cap in the first position, and turned heat on. anything else?

not sure this will work on a 95 due to the difference in location of the temp sending unit but i just loosend the sending unit so the air could escape then i started it up and once all the air escaped and coolant started to flow out i re-tightened it up before turning the engine off.

 

[.40CalPatriot]

Park the jeep with the front of the vehicle facing down (like in a ditch) and pull the temp sensor at the back of the head to let the air escape .

its a 95 i dont think it is the back of the head. i think it is in the thermostat housing .

 

[xjkraut]

thanks guys
i'll let you know if problem persists

 

[BudgetXJ]

Another quite effective way to burp the system is to pull the heater hose off of the thermostat housing or simply installing a flush tee into the heater hose. With the vehicle running, gently pull the heater hose off of the housing (being careful not to stand where you might get sprayed). Wait for the coolant to start coming out of the housing/hose and reconnect the hose making sure to tighten the hose clamp properly. 9 times out of 10 this solves the problem.

 

[XJANDTJ]

HEY I HAVE A 1989 CHEROKEE AND AM GOING THRU THE SAME PROBLEMS W/COOLING.MINE WAS TAKING ABOUT 30 MINUTES AT IDLE TO OVERHEAT TOOK THE T-STAT OUT AND FOUND IT WAS BROKEN.INSTALLED NEW T-STAT AND IT OVERHEATED IN 10 MINUTES.LAST NIGHT I TOOK THE UPPER RAD HOSE OFF AND ADDED WATER IN THAT WAY IT TOOK ALOT OF WATER AND NOW IS RUNNING JUST ABOVE 210.

 

[xj88superjeep]

HEY I HAVE A 1989 CHEROKEE AND AM GOING THRU THE SAME PROBLEMS W/COOLING.MINE WAS TAKING ABOUT 30 MINUTES AT IDLE TO OVERHEAT TOOK THE T-STAT OUT AND FOUND IT WAS BROKEN.INSTALLED NEW T-STAT AND IT OVERHEATED IN 10 MINUTES.LAST NIGHT I TOOK THE UPPER RAD HOSE OFF AND ADDED WATER IN THAT WAY IT TOOK ALOT OF WATER AND NOW IS RUNNING JUST ABOVE 210.

Hi, For your jeep with the closed system it is a little different... His has a radiator cap. But in your case, next time you need to refill the rad, what you need to do is start the engine, and add fluid to the reservoir tank while its running until it does not take any more fluid. then cap it off and drive 2 or 3 miles letting the air work it's way up to the reservoir... then AFTER it cools down, top off the reservoir again just to the top of the post inside.

 

[Ecomike]

There have been reports of aftermarket thermostats causing overheating that were corrected by using a dealer thermostat, and 5-90 and I have good luck with 180 F thermostats on the renix engines, 87-90.

I have never had problems with air in my renix systems, except when some of the inlet tubes of the radiator were partly scaled over on the passenger, inlet side, , in which case the air was trapped in the radiator tubes. Of course the radiator needed replacing as well, or the core needed to be rodded out.

I have never had to fiddle with burping a Renix engine, but I have always left the thermostat housing radiator hose loose, while I slowly filled the coolant bottle. takes about 20 to 30 minutes of filling and refilling the coolant bottle, but this way the engine fills first, then the engine fills the radiator and pushes the air out the top of the radiator hose and very slowly out the thermostat housing. Be sure to keep the coolant bottle filled to the very top during the fill process.

Then after a full warm up and drive, followed by a cool down, I top off the bottle one last time to the 1/2 way mark.