Remote oil and tranny cooler?

The short story is: 91 4.0/AW4 runs hot (225 and slowly climbing) at idle or crawl on 100+ degree days. This last weekend was 103, crawling on granite (that felt 120) but, it does the same thing on the blacktop in heavy traffic at 6pm. . . At any other time, temps are 195-205.

I can't find anything wrong with the cooling system, fuel mixture or cat, I've spent 3 summers swapping parts. . .

Motor is a 95 Mopar Crate - maybe 20,000 miles on it.
Tried 3 different radiators - settled on a 2 core with new cap.
Banks exhaust with new cat and muffler.
Fuel mixture - OEM injectors, tried adjustable MAP = no difference.
Auxillary Fan - late model and comes on appropriately.
Clutch Fan - replaced 3 times, latest is a GC fan.
Replaced the stock water pump with a Hesco high flow.
Thermostat - 4 or 5 different ones - latest is a Robert Shaw.

Prior to the Hesco pump / GC fan and new thermostat, it was scary hot, they did make an improvement. The fan screams, and the temps come down once I'm rolling. I've got a Warn 9000i sitting on the front bumper but, it sits low so, there's minimal air restriction.

"Fixing the stock cooling system" didn't work on this one. I'm about to try one more flush and add Water Wetter - maybe it'll work but, I doubt it. FWIW, I've got 4 other cherokees with stock cooling systems and NO issues. . . I'm DONE working on the cooling system on this one! For whatever reason, I need another solution for getting about 10% more cooling.

The AW4 has about 215,000 on it but no slipping or other issues - plumbed through the radiator and the OEM aux tranny cooler.

Oil pressure is excellent on this motor so, I'm thinking a remote filter and plate style cooler would add the extra cooling it appears to need - OR, adding a larger remote transmission cooler with a separate cooling fan.

Mine gets hot when climbing hills at low speeds. I think it's because the tranny fluid transfers the heat to the coolant before it leaves the radiator causing the engine to be hot. I think a beefy aux tranny cooler with it's own fan and taking the tranny fluid out of the radiator may be the fix for you.

jeeperjohn said:

Mine gets hot when climbing hills at low speeds. I think it's because the tranny fluid transfers the heat to the coolant before it leaves the radiator causing the engine to be hot. I think a beefy aux tranny cooler with it's own fan and taking the tranny fluid out of the radiator may be the fix for you.

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Yeah, that was the first thought out on the rocks this weekend - bypass the radiator and run the tranny cooler separate - was looking at 26000 or 30000 GVW coolers with an attached fan.

Any one have an idea what the tranny cooler integrated into the radiator is rated?

try a mechanical coolant temp gauge.

3XJFamily said:

Yeah, that was the first thought out on the rocks this weekend - bypass the radiator and run the tranny cooler separate - was looking at 26000 or 30000 GVW coolers with an attached fan.

Any one have an idea what the tranny cooler integrated into the radiator is rated?

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I don't know if it actually has a rating but it is not sufficient for towing in high air temps.

reelbigdundy87 said:

try a mechanical coolant temp gauge.

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??? I'm not sure how that'll help - Temps were confirmed with the IR temp gun in the shop the stock temp gauge is accurate enough.