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Still Overheating. EVERYTHING changed.

Additionally, as I replaced the water pump, I rotated the impellors in the same direction the belt would turn them and they were definitely rotating in the correct direction.
 
on the original engine?. Have you pressure checked the cooling system?. I have a 2000 xj w/ same mileage. I think we both need long blocks. Bwah.
 
I hate to sound like I'm just repeating someone, but have you really looked at your cat? You can troubleshoot those with a vacuum gauge. My 92 (yeah yeah, not obd-ii, but whatever) had a plugged cat with similar issues. I would overheat for no reason at all even with nice new cooling equipment. Once the cat was fixed I stopped overheating. That was in New Mexico on hot days with the AC on.
 
xeroOTG said:
I hate to sound like I'm just repeating someone, but have you really looked at your cat? You can troubleshoot those with a vacuum gauge. My 92 (yeah yeah, not obd-ii, but whatever) had a plugged cat with similar issues. I would overheat for no reason at all even with nice new cooling equipment. Once the cat was fixed I stopped overheating. That was in New Mexico on hot days with the AC on.
Click to expand...

I was just popping on here to throw that idea in the mix as well. I've got a new cat inbound to replace my factory original cat. I'm currently sitting at 185,500 and along with low power and gas mileage the area over the cat in the passenger compartment gets very hot and I have oddball cooling issues even though the Jeep has had the cooling system gone though and checked for head gasket leaks.
 
I like old_man's suggestion for cat, but no comment about power problem...

I like old_man's suggestion about running lean & MAP, too..

Otherwise I'm back to fault parts or an incomplete diagnosis on the head/head gasket.

If exhaust gases are leaking into the coolant... does your upper radiator hose stay pressurized overnight?
 
Do you still have the radiator you replaced? On my previous jeep, it would cool great when driving, but not so great when at a stop. I replaced the radiator and it cooled well for a month or two, then the same issue. I ended up cutting the tanks off the old radiator and discovered the fins were clogged with some thick sludge. I flushed and flushed the system until things were much better.

I second the comment about not needing the e-fans. Your stock engine fan moves a large amount of air. Also, with three fans how many amps are your requiring to power them?
 
Last edited:
Put it a 2 core all aluminum radiator .
You want wide tubes. 1" ideal. 3/4" not bad .

Wire in a 99+ Efan. Wire it to a switch on the dash . Run it
All the time if needed.

Run a mechanical gauge to inside the cab to verify temps off the t stat housing.

High pressure cap.

Are you sure gauges and sending unit are good ? The mechanical gauge above will ensure your readings are right .
 
Yes, in my experience, your overheating will be worse with the dirtbound set up:
http://naxja.org/forum/showthread.php?t=1101536

As stated above, wire a switch to the efan and flip it on at the first sign of climbing temps. I've done this for years and it keeps the temps under control.
 
blondejoncherokee said:
Put it a 2 core all aluminum radiator .
You want wide tubes. 1" ideal. 3/4" not bad .

Wire in a 99+ Efan. Wire it to a switch on the dash . Run it
All the time if needed.

Run a mechanical gauge to inside the cab to verify temps off the t stat housing.

High pressure cap.

Are you sure gauges and sending unit are good ? The mechanical gauge above will ensure your readings are right .
Click to expand...

IMHO, this is the best option on the market for a radiator right now -

http://www.summitracing.com/parts/sum-382012/overview/year/1999/make/jeep/model/cherokee

I base this on this was the ONLY radiator that we have found that will keep the temps in line on our desert racer. We tried all the big $$ aluminum, 2 row, 3 row, blah, blah. I guarantee we push our cooling system WAY harder than anyone here - we are talking foot on the floor, 5000 rpm, 2nd gear, for 10 miles pulling uphill through a sand wash. The best aluminum would get us to 240 easily and we would usually have to ease up to get it to stabilize. The radiator I just linked to will keep us at 220 through that, and keeps us below 200 for just about everything else. And that is with 2 stock electric fans.

Facts - the 3 row has tubes that are too small - not enough tube surface area. 2 bigger rows are better than 3 smaller. A lot of cheap chinese aftermarket aluminum radiators have the fins glued (epoxied) to the tubes, which essentially insulates the tubes from the fins. If you want aluminum, make sure the fins are furnace brazed to the tubes so you have the best heat transfer. Copper is a better heat conductor than aluminum. The problem is that cheap copper/brass radiators started getting their fins either glued or lead soldered to the tubes, which again kills the heat transfer. Again, find a good radiator where the fins are brazed to the tubes.

As for water pumps, Flowcooler work great at low RPM, such as trails. They suck everywhere else. The best we found is the Hesco for higher speeds/higher loads (i.e. freeway), and it works awesome at the low speed stuff as well.
 
I chased an overheating problem for years, tried bigger radiator, better fan clutch, hood vents, nothing seemed to cure the issue.

Finally got proper gearing, and BAM problem solved.
 
Transpoquick said:
on the original engine?. Have you pressure checked the cooling system?. I have a 2000 xj w/ same mileage. I think we both need long blocks. Bwah.
Click to expand...

Yes it is the original engine and Yes I had the mechanic pressure check the cooling system. He removed the radiator cap and hooked up this contraption to the radiator and pressure checked it. It was good.
 
xeroOTG said:
I hate to sound like I'm just repeating someone, but have you really looked at your cat? You can troubleshoot those with a vacuum gauge. My 92 (yeah yeah, not obd-ii, but whatever) had a plugged cat with similar issues. I would overheat for no reason at all even with nice new cooling equipment. Once the cat was fixed I stopped overheating. That was in New Mexico on hot days with the AC on.
Click to expand...

The cat is about 2.5 years old. I'm definitely not against having it checked out. I'm compiling a list of things for the mechanic to check out and catalytic converter just made the cut. Thanks for the input.
 
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