External Oil cooler (engine)

[Luksa84]

Ok so long story short, the 2000 TJ engine heats up on some strenuous hills. Only noticed it once but it was climbing on some others here in PA on route 80 that i thought it shouldn't have. Have an electric fan that came with the Jeep (not removing so lets stay on topic), and was debating a small 10 row external engine oil cooler.
Questions:
1. where the hell would you mount it? trying to get it in the front grill is a PITA.
2. the kit takes a different oil filter, that an issue or not?
3. would a thermostat that opens at a lower temp help?

The jeep has run very well with minimal issues, its going out west to utah in August 2023 so i figured with more hwy hills it could use something to cool itself. No it does not overheat at all when going slow or in 4wd wheeling offroad.

 

[TexasTJ2004]

Don’t use any lower temperature thermostat. It will only damage the engine.
Thermostat is responsible for minimum operating temperature, the moment it crossed (195F), it has 0 impact on cooling.
Engine oil cooler will have very small impact on the overheat, the goal of it is to prolong the life of the oil, by preventing it going to hot. Replacing the thermostat with Mopar/Motorad unit is a generally good idea, as a preventive maintenance, it is possible that it does not open properly.
Overheat on highway usually means or blocked airflow, or overall bad cooling system. Try proper flush, with evaporust and with preston( separate flushes). When you flush drain the engine block.
Make sure that you have no air in the system, burp it properly.

 

[Jerry Bransford]

X2 to the above, installing a lower temperature will not and cannot reduce engine temperature in warm or hot conditions. If it was that easy to reduce the temperature of a hot engine we wouldn't need the big radiators we do. The thermostat has just two jobs... 1) to help the engine warm up more quick and 2) to help set a minimum operating temperature in cold conditions.

And an oil cooler isn't going to help either, that's not the way to get an engine temperature back down to where it should be. When an engine gets hot too easily while driving on the highway there are only a few possible reasons for it. 1) the radiator is badly designed aftermarket which doesn't have the reserve cooling capacity the OEM Mopar radiator has. 2) the radiator is clogged from either mud on its exterior or clogged internally with either sludge or hard water deposits. 3) the shroud around the engine fan is missing or not completely intact. 4) the water pump is dying. 4) the thermostat is starting to hang up on the verge of closing when it should be wide open.

I'd start with the above suggested items. And if you decide to replace the thermostat, just go with a good quality conventional 195 degree thermostat. Avoid so-called "fail safe" thermostats that are well known to fail entirely too easily and readily in the open/non-operational mode, they just aren't likely to fail in the closed position.

And avoid converting your OEM serpentine belt driven fan to an electric which would be a downgrade cooling-wise. Us desert wheelers who stupidly wheel in hot conditions learned long ago to stay with the OEM design cooling system and avoid silly things like electric fan conversions that don't work well and are well-known to fail at the worst possible times. Every time I stopped to help an overheated TJ in the desert it has an electric fan conversion and usually with a cheap aftermarket radiator too to add insult to injury.

 

[JustDandee]

(Curious)which oil cooler kit did you buy? I would not be concerned with using another filter part number if it is at least the same size or larger than OEM and still purchase one that has a anti-siphon. I would scan the transmission cooler threads for mounting ideas on he physical cooler.

But for the running warm/ overheating issue you won’t find better advice then what has been shared.