Originally Posted by robsjeep

I disagree with your first comment. Take a look at my prior post made this morning, a bit before 7 a.m. Bunch of questions answered.

Originally Posted by 4.3L XJ

Well, no one has answered his question. But here are a few thoughts.

High flow water pumps are a waste of money. Sounds good in theory, but the fact is that the pump will pump more coolant than necessary to properly cool the engine, much more. THEY MAY NOT COOL BETTER, SOME DO FLOW MORE THAN STOCK, FLOW MORE WITH LESS HORSEPOWER BECUASE THE BLADES OF THE IMPELLER ARE MORE EFFICIENT TYPE, THESE PUMPS MAY BE OF BETTER QUALITY THAN STUFF MADE IN RED CHINA. BUY AMERICAN!

Performance tstat. Same thing same answer. A GOOD THERMOSTAT MAY BE LESS FLOW RESTRICTIVE AND BE BUILT WITH HIGHER QUALITY, SO LESS LIKELY TO FAIL, OR PARTIALLY FAIL THAN THE LOW COST "HENCHO IN RED CHINA" THERMOSTAT.

Cooling is all about temperature transfer and air flow. So, a clean radiator and cooling system is essential. YES CLEAN RADIATOR INSIDE AND OUT! BEWARE OF AFTERMARKET BUMPERS, WENCHES, LIGHTS THAT BLOCK THE GRILL.

Air flow can be increased by eliminating the fan clutch. More air flow equals more cooling, up to a point. Some have put a ZJ fan clutch in, which will make the fan spin a little faster since it is a heavier clutch. WITH NO CLUTCH, YOU WILL BE WASTING FUEL, AND AT HIGHWAY SPEEDS THE NOISE MAYBE VERY IRRITATING AT HIGHER ENGINE RPMS. AT FREEWAY SPEED ON THE LEVEL, MODERATE WEATHER, YOU DONT NEED MUCH FAN SPEED, AS THE RAM AIR FROM 70 MPH COOLS THE ENGINE ENOUGH SUCH THE FAN CLUTCH WHICH IS TEMPERATURE CO TROLLED, WILL ALLOW THE FAN TO IDLE. NOW THE GRAND CHEROKKE CLUTCH , THAT IS A GOOD IDEA, I DONE THAT. IT IS A TIGHT FIT, IT WILL MOVE THE FAN A BIT CLOSER TO THE RADIATOR, THIS ALLOWS THE FAN TO WORK AS DESIGNED, ONLY POWERED WHEN HOT, AND COASTING WHEN COLL, SAVING GAS, AND CUTTING NOISE. THE GRAND CHEROKEE HAS LESS SLIP, YOU GET A BIT MORE FAN RPM WHEN IT IS ENGAGED

Having a full shroud on the mechanical fan instead of a partial shroud will increase air flow. The fan blade should be half exposed outside of the back of the shroud to allow centrifugal slinging of air and thus increasing the flow. (Really, backed by research in the HVAC industry) INTERESTING, GOOD TO KNOW, THANKS

Anything more than a single core never hurts, if you have the air flow to go with it. BIGGER IS BETTER OFTEN FACTORY HEAVY DUTY OR TOW PACKAGES EVEN INCLUDE BIGGER RADIATORS, GREAT IDEA IF YOU DRIVE HARD, TOW, DESERT.

Wiring your efan to operate all the time doesn't hurt either. WHY RUN IT WHEN THE ENGINE IS COLD? THE THERMOSTAT CONTROL SHOULD BE FINE, IF YOU DO BYPASS THE THERMOSTAT, PUT IT ON A DASH SWITCH SO YOU CAN CONTROL IT WHY RUN THE FAN ON A FREEZING DAY FOR A SHORT DRIVE?

If you decide to run an electric fan set up, make sure total air flow is greater than 2000 cfm IF THAT IS MORE THAN STOCK, THEN YES

Venting the hood in the proper place. There is currently an active thread on that. MY FRIEND DID SOME EXPERIMENTS, HE HAS A 2001 WITH THE TWIN ENGINE MOUNTED CATALYSTS, HE FOUND NO CHANGE IN OPERATING TEMPERATURE WHEN DRIVING, AND A LITTLE BIT OF COOLING WHEN PARKED. IT ALSO DID DUMP HEAT INTO THE COWL FRESH AIR INTAKES THAT FEED THE DASH VENTS . MY XJ EVEN HAS THE FACTORY HEAT TRAPPING HOOD BLANKET ON IT, BUT IT OF COURSE DOES NOT HAVE THE 2001 MODEL TWIN ON ENGINE CATALYSTS BUT YES, THE FACTORY DID PUT PADDING UNDER PRETTY MUCH THE WHOLE HOOD, THEY HAD NO CONCERNS WITH HEAT VENTING OUT THE TOP, THE WHOLE BOTTOM IS OPEN AFTER ALL.

Separate transmission cooler, if adequate can help too by removing a heat source from the return coolant to the engine. YEAH, BUT THE RECOMMENDED LOCATION FOR THE TRANNY COOLER IS IN FRONT OF THE RADIATOR, SO THE TRANNY HEAT WILL BE ADDED TO THE RADIATOR, PLUS THE TRANNY COOLER BLOCKS AIR FLOW SOME, PROBABLY LITTLE IF ANY CHANGE WILL BE SEEN ON ENGINE TEMPERATURE, BUT IT IS A GOOD IDEA TO HELP IMPROVE TRANNY LIFE

Adding an engine oil cooler can help by cooling deep internally. IF THE OIL IS GETTING TOO HOT, FIGURE OUT WHY. IF YOUR ENGINE WATER TEMP IS FINE, AND OIL TOO HOT, THEN SOMETHING IS WRONG, ADDING A COOLER IS NOT THE FIX. IF BOTH OIL AND COOLANT ARE TOO HOT, FIX THE COOLANT TEMP PROBLEM FIRST, AS IT IS LIKELY THE CAUSE FOR HIGH OIL TEMPS. IF YOU TOW HEAVY, DRIVE DESERT HEATS, RACE, REALLY WORK THE MOTOR, AN ADDED COOLER CAN HELP IF YOU RUN THE ENGINE ON THE HOT SIDE. BUT UNDER NORMAL USE, THE ENGINE SHOULD NOT RUN ON THE HOT SIDE, SO OIL SHOULD NOT BE TOO HOT, UNLESS SOMETHING IS WRONG

I am sure some will disagree, but those are all proven things to consider

Originally Posted by 4.3L XJ

OK, we can discuss the water pump, I assume that is what you mean. Assuming the radiator is not restricted, then the pressure of the stock water pump is just fine. The reason the tstat restricts flow is that the water pump is sized to pump too much, if that much is needed. But the hydraulics of a centrifugal pump (lots of experience with these in the fire service) is that they can "slip" That is that if flow is restricted by a nozzle or in this case thermostat the pump doesn't have to be stopped. It can keep going any speed. Your point about wear is right on though, the vanes can corrode due to acid in the coolant and cause it to underperform. But if the coolant is maintained the way it should be, the seal and bearing will fail long before that

Originally Posted by XJ_XJ

Obviously I was wrong in some of my guess thanks.

I like all the feedback, but thanks for the details. To the best of my knowledge I have never had a Jeep run at the correct temp, always a little over. haha

What makes more sense the transmission cooler to engine cooler? Transmission, since it would help towing?
Also how do you wire the efan? Are there directions for that?
What is engine cooler? <- Ice?

Originally Posted by robsjeep

Actually I refer to your comment that no one had answered his question. I answered a bunch of his questions in my post this morning, line by line I answered them. you didnt see that I assume.

if you got a higher flow pump, you may need a higher flow thermostat. for stock parts, which is the limiting factor? often the performance pump and thermostat is of better quality than stock, is USA made, and the pump can move the coolant for less horsepower to drive it, thanks to a much better impeller design. the stock impellers are crude sheet metal parts, some performance impellers are twice the blade count, cnc machined from a disc of aluminum to a complex curved blade for optimized effeicincy. the quality performance thermostats not only may flow more, but be of better materials, with a better more fail safe operating mechanism, for correct full open and full closed operation for years to come. cheapo thermostats may have inferior mechanism, where the wax leaks past the seal easily, resulting in a themostat that over time gradually fails to fully work, eventually failing to operate at all. why risk cooling system failure on the cheapo part, this is the brain, the control of the cooling system. Buy Quality American for best results. cheapo red chinese parts, well, you get what you pay for, i.e.... very little

Originally Posted by ELC_AMX

Just change your coolant at regular intervals, check for any corrosion or rust on any parts, and make sure your coolant temp gauge/sensor is operating correctly so you can easily tell when a problem arises.

If we're literally just trying to list out things that can help cool your vehicle's engine regardless of cost, convenience, and practical feasibility, then there's tons of crazy cuckoo things you could do including running pure water, no antifreeze, high-flow radiator fans, mechanical fan delete, dual/triple core radiator, etc... You could even find a way to make your XJ run on methanol, that would help a lot.

But from a practical standpoint, unless you're modding the out of your XJ then a stock system will do just fine. One mod that I will always recommend are hood vents in the proper position, as chronicled here: https://www.cherokeeforum.com/f67/xj...riteup-261924/

Vents in this position will assist your radiator fans in drawing air through the radiator at low speeds, thereby increasing your radiator's efficiency and increasing its cooling capacity while on the trail or on the rocks.

Originally Posted by XJ_XJ

What parts could you replace in your Jeep in order in to keep the heat down?

Could a Continental Elite Serpentine Belt or some type of serpentine belt reduce heat?
What about high pressure water pump?
What about a new performance thermostat?
(does a lower opening temperature help?)
What about a low or high pressure radiator cap?

92 XJ Manual

Originally Posted by XJ_XJ

This is cool. In what areas can I run my Jeep year round with no coolant? I think there is some preserving stuff that the coolant has, is there away to buy the preserving stuff without the antifreeze?

Originally Posted by MaskedMallard

My 2001 XJ, when I first got it, ran on the plus side of 210*F. After I did the following;
- Hesco highflow water pump.
- Hesco highflow thermostat housing.
- Hesco thermostat.
- 3 row radiator.
- external transmission cooler plumbed through the radiator.
- silicon radiator hoses & heater hoses.
- 50/50 coolant mix with distilled water.
- water wetter.
My XJ now runs on the minus side of 210*F. I'd guess I dropped the normal operating temperature by 5*F. That puts the XJ that much further away from boiling over.

Originally Posted by robsjeep

NO, No, No! Dont mess with it, use the standard 50 to 60 percent anti freeze in distilled water. flush and change every two years, use Prestone green extended life antifreeze, or equal quality other. do not mix antifreeze types, some are not compatible.

you need the boil over protection, you need the freeze protection, you need the corrosion protection, you need the seal lubrication on the pump shaft. antifreeze does these things.
the whole system is designed around the correct coolant. run too liitle prestone and you will find she boils over to easily, so you will need a higher pressure system, higher rated cap, but then, can the hoses, gaskets handle your new higher pressure? What happens when it boils easy and forms steam pockets in the engine? ( you get hot spots,)

Leave it the frickin heck alone, use the standard coolant mix that 99.999999% of the water cooled cars use.

you run straight water, i will laugh my rear end off when she boils over, gets freeze damage, corrodes, leaks, and fails on you.

No, no, no, no, no, no, no, no, dont even go there, no!

good luck

Originally Posted by ELC_AMX

Yeah, that's why I listed it after the "this stuff is fantasy" disclaimer. Antifreeze does have a higher boiling point, but water offers better heat transfer to more efficiently get rid of heat from the engine as it passes through the radiator. Once the water is pressurized to 15psi it has a boiling point of approximately ~255°F, so unless you are actively attempting to overheat your engine, it will keep the engine cooler than anything mixed with antifreeze due to these heat transfer properties while not boiling, steaming, and creating hot pockets that lead to blockages of coolant passages and then overheating.

But yes, for daily driving of any kind straight water is something only an idiot would do. No freeze protection, no anti-corrosion protection, etc... Some people run just water all the time if they live in places like deserts, and it does help, but if you live anywhere with a possibility of freezing weather you never want to run the chance of forgetting you have straight water in your engine and radiator.

Also, I dunno where you'd get just anti-corrosion additives XJ_XJ, maybe check a racing forum.

Originally Posted by robsjeep