Nicnic100

Okay so the new gauge came in today and I installed it. The XJ is still overheating but it does not show that it is fetting quite as hot, maybe topping at 225. Is this a safe temp at idle? I know its high but I don't know what else to try. Since my compression test came back perfect, does that rule out a leaky head gasker? Also, what should I try next? I would really like the Jeep to run no higher than 210.

Willys55

I have run into a few XJ's that were overheating, and rather than dye in the coolant I would put the sniffer pipe from our inspection machine over the radiator neck and watch for the Hydra Carbons to spike on the meter. Is there a shop in the area that has a sun analizer or that does inspections (emmissions) that could do this test for you.

blackjeeps420

I've had the same prob after a head job I did, so I did a full cooling system swap, then my little bro showed up & bled some valve, or maybe it was a sencer & fixed it. If you can't find it all call him to locate it but we just bled it tell coolant flowed out and it returned to running at normal temp. good luck (I knew it wasn't the head gasket, it was brand new)

archebald23

yes, i wonder whats with those chinese thermostats. i had one and it yield nothing but erroneous results. stay away from those and get your jeep grand cherokee parts from credible establishments.

Frugal

Someone else on this forum had a post about overheating and found out after replacing everything that the line from the radiator to the overflow bottle was plugged up. I popped mine off today and sure enough it was plugged from one end to the other. I should have just bought a new line but being used to doing combat fixes I grab some weedeater line I had laying around and worked it through the hose(you have better luck if you have a mallet, I layed my hose on the ground and tapped it a couple of times). After I got the line worked thru the hose I tied a knot in the weedeater line and pulled it all the way thru the hose, you would not believe the crap that came out of other end. Anyway I took it for a test drive and it stayed steady at 195 which is the thermostat temp I'm running. At idle with the AC on it will stay just under 210 degrees, so thanks to whoever posted that on one of the overheating threads.

pindrums

Reading all these comments is good info. I've replaced my water pump, radiator, new NAPA 180 thermostat & housing, new hoses and now 3 10" fan electric cooling fans. and engine compartment is so hot - it's hard to open the hood --- HOT! Temp is around 195-212 in traffic - a little cooler on the road. My 4th Cherokee - the others never gave me any heating problems. It's boiled over twice at around 225-230 degrees! (prior to radiator replacement). Going to swap out thermostat with a Stant 180 and put a hood louver kit on. Then that's it - nothing more!!! I'm going to start towing a 20ft camp trailer i bought so don't want any problems!! Yes, I noticed I forgot to put my pos battery cover back on! haha

BlueRidgeMark

Bad idea. Contrary to urban legend, a thermostat does not control the temperature of the engine. All it does is control when the water starts flowing. A lower temp t-stat will not cure an overheating problem, or make your vehicle run cooler. (Unless all you do is very short runs.)

What it WILL do is to make you stay in open loop longer, hurting your fuel economy. It's a bad idea.


The stock system will keep your engine at the correct temperature in slow traffic, in Phoenix, in August. We know that because we have members here who do exactly that. What this means is, if your system is overheating, it does not need to be re-designed with high performance parts. It needs to be fixed. Something is wrong. Find the problem and fix it. Might be running lean, might have a gunked up block, and the list goes on. All kinds of things could be wrong that you haven't mentioned.


Sounds like a recipe for disaster. The tow rating on a Cherokee is only 3500 pounds, 350 tongue weight. (It's 5,000 ONLY if you have a weight distributing hitch.)

You have a 20 foot trailer that meets that? It's not about making it go, it's about stopping it. And it's about controlling it. With a 20 foot sail behind you, any crosswinds will toss you around like a cork. I think you'll make YouTube within a few months.

Aside from that, have you installed an extra transmission cooler? Preferably two, with that load. One BEFORE the radiator and one AFTER the radiator. A transmission temperature gauge is not a bad idea, either.

Even with the extra cooling, keep that transmission in 3, or you will be having fried transmission for breakfast.

Were you thinking you'd be doing 65 down the Interstate? Not for long, you won't.

pindrums

You are correct to a point, but actually it does run cooler on the highway with the 180 degree thermostat [I noticed an immediate difference] - in traffic - no. Doesn't change my fuel economy at all as I've taken several long trips and kept close watch on my mileage / fuel usage. I simply replaced a similar electric fan setup in the vehicle when I bought it as a fastener came loose and the pully chewed up one fan, so my choices were to replace the system in place, or go back to the OEM setup. You are right about finding the problem and fixing it, but as you may see, I'm working through the system to do exactly that & re-reading my statement saying "that's it, nothing more" is probably NOT accurate! haha

4.3L XJ

So you have electric fans. They are not all created equal. How many CFMs do the fans pull when all are running?

pindrums

I don't remember the CFM's (numbers)but it was quoted per manufacture at more than double OEM mechanical ratings. Currently - 3x10" fans. It pulls some serious air out of the engine compartment vs the 3 x 9" elec. fan setup before!

4.3L XJ

the reson I ask is that most efans don't pull that much air. The OEM mechanical pulls 1900 and efan pulls 1100 cfm. So unless those fans are rated at least 1000 cfm, you are pulling less air than OEM

toohott2run

change your radiator cap!

tech

Ok when you say you changed new coolant sensor with one did you change because I think your year has one for the computer and another one for the gauge , also the fan clutch did you change it ?