At least inspect it. It will only cost you a gasket to do so. Backflush the heater core. and

 

Agreed here. Inspect the water pump and replace (I like NAPA for this) if necessary. At the same time at least flush the heater core (back and forth) if not use the opportunity to flush the engine and the radiator. It's nice to be able to flush these three sections separately from each other anyway so that crap doesn't have to travel through the whole system before it gets expelled.

The system holds 12 quarts, so after the flush, add 6 quarts of pure antifreeze (not 50/50) then add as much distilled water as necessary to top it off (you'll have to check and probably add a little more after the system has been run and burbed air bubbles out). Do it this way instead of 12 qts of 50/50 because there will probably be some water left behind after the flush, you'll probably use slightly less than 6 quarts of distilled water to top it off as a result.

 

So flushed the whole system today and changed all the hoses upper lower radiator and the heater upper lower flushed it a total of 3 times and put everything back on filled it up with fluids and stated it burped the system and everything is fine its running at 180 to 185ish let it run for a straight 20 min at this range and it stayed there so I got in and took her for a drive about 5 min into my drive the temp started creeping up slowly until it hit 220 and the aux fan kicked on and I won't go past that the 220 so Idk if it's my radiator not disapating the heat enough or my water pump is starting to go or if I just got a faulty stat from autozone I don't want to change the radiator if it's just the water pump vise versa or should I just buy another stat from the dealership Idk what to do plz help me out

 

Stant SuperStat 45359 is my choice for thermostats.

Check the fan clutch. To check the clutch fan, disconnect the bimetal spring and rotate it 90degrees counterclockwise. This disables the temperature-controlled, free-wheeling feature and the clutch performs like a conventional fan. If this cures the overheating condition, replace the clutch fan. Or a quicker but sloppier way to get an idea is if after the engine has been warmed all the way up, turn it off and go give the fan a spin; give it a flick and it spins for more than one revolution, the clutch is shot. Or if it continues to spin for awhile on its own right after you turn a hot engine off, it's bad--it should stop with the engine pretty quickly. Honestly, if it's the original fan clutch, just replace it; it's almost certainly shot. They don't last forever (5-10 yrs at best maybe?). They're like $30-40 at NAPA.

You don't need to guess about the water pump--pull it and see if it is bad or not; too bad you didn't do this when you had everything drained since you'll have to drain some coolant again.

Assuming you have new hoses and have the spring inside the lower radiator hose (keeps it from collapsing) and all of the above checks out, then it's time for a new radiator.

 

So I've noticed the radiator was replaced before I got it I knew this because the transmission line that hooks up to the radiator doesn't have the quick disconnect thing on it anymore and it's just hooked up to the radiator by an hose clamp could this cause a problem and could it be the reason why I'm running over 210 about 25 min into a drive ?

 

No. Honestly, the elimination of the quick connectors is a good thing. The quick connectors leak like no one's business. Either way--shouldn't impact temps at all.

Time to repeat myself...

Have you checked your fan clutch yet? Make sure you check it and replace it if necessary because it's cheap and easy, and if you do something like throw a bunch of money at a new radiator, a bad fan clutch will still lead to overheating. If your fan clutch is good, what about your water pump? Checked that yet? If that is good, considering all the flushing you've done, THEN get a new radiator.

 

No. I think it's very likely your radiator is clogged and that's why your engine is running a little hotter than it should. I have a 195 thermostat installed. This time of year, my electric fan never comes on and the the temp never gets above 210.

I know it's a real bummer, but I would suggest you replace your radiator now. Otherwise, it's very likely you'll have some serious overheating issues when the weather gets warm. (It may not seem like it now, but the weather will get warmer.)

Try to flush your heater core by disconnecting both hoses at the engine. Connect a garden hose as best you can to one side and see if you get flow out the other side. Do this to both sides. If you don't get good flow through the heater core, replace it. It's as simple as that. Once it's good and clogged, it's nearly impossible to unclog it and it should be replaced. A properly functioning XJ heater will almost allow you to roast a chicken in the passenger seat. Anything less suggests a clogged heater core.

 

Regarding the big debate in this thread and others;
There is official documentation of 210 being the ideal running/operating temp. It is on our dashboards, the hash-mark where all of our jeeps happily run, 210.

 

I haven't looked at the water pump yet and the only reason I don't think it is the radiator was because before I changed the thermostat it was running cold the shoot up to 210 the back to cold like 120 to 140 could the thermostat just be faulty or would the thermostat just not open if it was faulty I'm going to get a new stat tomorrow and change it and I'm getting the mopar 195 from the dealership I just really don't want to buy the new radiator and that not be it and I don't want to have to change the water pump if that's not it I also did just notice today that when my jeep got painted a couple of weeks ago and they did not cover the grill on the inside so all of that got painted too the radiator the other thing that's in front of the radiator (forget what's it's called ) could this be the problem ?

 

How about testing your t-stat? All u need is a pan of water on top of the stove with a cooking thermometer and about 10 minutes. Bring the temp up slowly (like it does inside the motor) and observe the stat "open" temp.....should be about the stat's rating. The stat should open very slowly, very smoothly 'til it reaches wide open at about 15* above it's open temp. Don't bring the water up to boiling.

 

If the gauge is not spot on accurate (as most factory gauges aren't), what would make it "official"? Virtually all factory temp gauges point to plus/minus the "middle", whether the gauge has a number there or not, no? Lots of folks post that their needle points between the middle of the gauge and the mark before the middle. Would that be considered unofficial? LOL

 

Generally speaking-overheating while stopped or at low speeds is an airflow issue and overheating while driving at speeds above 30 or so is a coolant flow issue. From what I've read here it doesn't sound like you have a bad fan clutch. One other thing to consider is system pressure. At idle the engine makes little heat and may stay cool with no pressure as there won't be any hot spots above the boiling temp of the coolant, under load you might get hot spots that do boil the coolant. If the cap doesn't hold the proper pressure you can start boiling which sets off a chain reaction to overheating. As far as testing the clutch by locking it, that won't accurately test the clutch from my XJ experiences. I've known two that ran really hot at low speeds while on an off-road adventure in 100+ degree weather and both had new clutches. I locked one with wire wrapped around the bolts and it ran safely cool. The wire didn't hold at high RPM tho. Both had new fan clutches, hoses, pumps, thermostats, cleaned systems, and functional electric fans. One only ran hot with the AC on (mine) and was ok when I got the revs up (manually held 1st or 2nd gear as needed a few times), the other ran hot even with the heater on. The other one had a new aftermarket plastic/aluminum radiator, mine has an old copper one. No clue if that is what made the difference or if it was something else, his did seem to not hold pressure well so maybe a bad cap was causing it. Both are 1990 with closed systems.

 

You can test for radiator blockage by running it long enough to fully warm up the system, shutting it off, and quickly feel the radiator looking for cool spots. If you find rows of the radiator that are cool they are likely blocked.

 

I have no dog in this fight but will give you a simple answer to what you had posted and various posts hundreds if not more here and NAXJA on this subject.....and my own personally.


The age of our XJ's being what it is and the general upkeep done on most cars after warranty isn't good by many people, not all. All most do is worry about the gas and some about an oil change now and then everything else only if it breaks.


When I first bought mine it didn't do the best job of cooling but worked and one of the first things I did was cleaning/flushing the engine and heater core 3 times, it was filthy so I stopped there when it showed up as clean. Then went to AutoZone and bought a radiator, water pump, fan clutch, new hoses, T-Stat & housing, belts and coolant. Removed all old items then flushed/back flushed heater core several more times finally got a big chunk out of it then installed everything. That was 3 yrs ago and have never had any issues since on the trails or on the roads.


IMHO this is one of the cheapest <$300 ways to insure a well operating cooling system now and for years to come instead of throwing money at it piecemeal, with just simple upkeep.


BTY don't be tempted by one of those cheap aluminum radiators as they are junk and start leaking in short order a stock one from AutoZone is <$100 and works fine.

 

It's also possible, maybe even likely, that flushing the cooling system dislodged a bunch of crud which is now clogging your radiator.

Replace the radiator and the heater core and don't look back. All other attempts at resolving this issue will be an exercise in futility.