Cooling System Overhaul

Ok, I've tried searching and have not really come up with my answer so here it goes.

Im trying to replace EVERYTHING on the cooling system. Radiator, Fan Clutch, T-Stat, and upper/lower hoses +Heater core hoses.

My Question is this. Which brand is going to work the best for each of these? OEM water pump? Flowkooler? Napa Brand?

Radiator I've pretty much decided on a 2 row CSF and t-stat going OEM from the dealer?

Can I buy everything minus the radiator at Napa? What are the part numbers? Should I run the ZJ HD fan clutch?

This is a 100% trail rig, I do not daily drive it at all. Just drive it back and forth to the trails so I don't care about loud sounds, I just want to keep everything nice and cool.

It's alot of questions but I couldn't find an answer to them all together.

Thanks!

Oh yea forgot!

95 4.0l AW4 NP231

I have a 2000 4.0 AW4 that was always overheating in the summer. I replaced the RAD with a CFS 3 core stock fan clutch...ZJ would not fit with the 3 core, Flowkooler water pump and added hood vents and trans cooler. never gets above 210 on the gauge. have now tested it wheeling all day in heavy mud really working the system on the highway loaded for a week of camping and around twon in stop and go. For me this worked great.

seems as though we r always dealing w/ cooling issues!
i did the-
radiator,
flowcooler high volume wp, it now makes my spliter to the heater core leak when warming up due to the low idle pressure, (no biggie)!
96 xj w/ tow package fan cluch pn#-272310 HD (napa)
Tstat
hood vents
she still loves to get warm but i now can contral her @ 210* mark cuz i installed a manual elec fan switch so when climbing i dont wait till shes hot i just flip the switch as i approach the obstacle, unless u can figure out how to fit an oversized radiator in there, i think i may have done all a person can do! the hood louvers really help too, i also made some plexiglass sheilds to close off the louvers in the extreme cold or wet weather to hold heat in, i just zip-tie em to the undernieth part of the louver, in some cases i run just one louver open! can text ya pics just PM me ur ##

My 97 update is more of a stocko daily driver that gets a bunch of highway speed towing ... and average offroad work ...

....but this is my current setup .... for life in 30*f to 110+* weather.

- 2row copper/brass rad,
- "stock" replacement, USMW Waterpump from rugged ridge,
- "stock" replacement, USMW fanclutch from rugged ridge,
- MotoRad 190 thermostat,
- Coolant mix of about 10% eth-gly/90% water, with a correct dose of anti-corrosive/anti-foaming agent additives,
- Bypassed the radiator AW4 tranny, heat exchanger and fitted a proper oil cooler up front,
- 1/2" hood hinge spacers and a larger firewall seal between the hinges ... air is vented / fanforced, from the hood rear corners at all driving speeds ... Might fit vents one day - when I find some that do what the hinge spacers & seal do.

Year round running temps are 195* - give or take a degree or two ... Only goes over 205*/210* if I leave it idling for half an hour in the driveway on a hot day ... havent had to used the aux leccy fan bypass switch in anger for nearly two years.


If it was getting a maxxed out revs flogging, offroad - instead of the lowspeed, low range, use it gets ... I'd probably bang in a heavier duty fanclutch ... rip out the front crossmember .. and put a proper radiator in there ... :shhh:

The USMW parts have all lasted 2yrs with no issues to date ... So Im guessing they are a reasonable brand ??

The MotoRad thermostat (premium version) is sold down here under another name ... and is probably the most common use, aftermarket thermostat in vehicles ... in the country ... but its just a thermostat ... like all the others

OEM is the way to go with these engines unless you want a high flow water pump. but im serious, the engine was made to run with the specific oem parts. some parts may cost more but if you want to do it the right way and make it last for at least a couple hundred thousand miles get oem. except for the radiator hoses, you could probably go gates for that or ac delco, but for the rest MOPAR!

master turner said:

OEM is the way to go with these engines unless you want a high flow water pump. but im serious, the engine was made to run with the specific oem parts. some parts may cost more but if you want to do it the right way and make it last for at least a couple hundred thousand miles get oem. except for the radiator hoses, you could probably go gates for that or ac delco, but for the rest MOPAR!

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In general ... I would agree ...

But theres no reason why a person cant buy the same brands that Mopar sticks their decal on .... or something else that performs equally as well.

Especially when you consider the extravagant pricing of OEM badged parts.

RAM-ROD said:

I have a 2000 4.0 AW4 that was always overheating in the summer. I replaced the RAD with a CFS 3 core stock fan clutch...ZJ would not fit with the 3 core, Flowkooler water pump and added hood vents and trans cooler. never gets above 210 on the gauge. have now tested it wheeling all day in heavy mud really working the system on the highway loaded for a week of camping and around twon in stop and go. For me this worked great.

Click to expand...

CSF 3 core will work with a ZJ fan clutch, just takes some massaging to fit it in place. This was on a 1998.

Definitely get a stand alone tranny cooler.