Engine Temp Question

[abebehrmann]

Last weekend when we went out on a trail ride I noticed engine temps a bit higher than usual, all the way up to 225F at one point. I know we were pushing it quite hard; it was a very hot day (95F+), we were driving around at slow speeds, with the AC on (swarms of biting horseflies following us all day), and we had to keep the rpm up a bit higher than I usually would in order to slog through the deep sand. Once I saw it get up to 225F, I cut off the AC and within a couple min the temp went down below 220.

A few weeks ago I changed all rad/heater hoses, flushed the cooling system, and installed a new thermostat and housing. I was wondering, do you think I should consider changing out the fan clutch and/or water pump? As far as I can tell, they are still working properly. In normal driving, even in stop and go traffic in 95+F heat, I rarely get above 210 which makes me think my cooling system is working well but I was just wondering what everyone else thought about this. Was this just a cluster of circumstances that led to a momentary jump in engine temp or is this a sign of a bad component in my cooling system? Any input would be greatly appreciated.
-Abe

[Carves]

I would just monitor the temps for a while ... Sand is a hard driving environment ... lots of drag on the drivetrain.

Have you had the issues in the same driving spot in the past ??

Fanclutch is something that ought to be replaced if you are not sure of its age/condition ... and the higher temps in the sand ... might, be an indicator the fanclutch is starting to lose its oomph.

Improving the cooling for the AW4 ... would also be a priority for me - for wheeling in sand.

... you still have the tranny connections to the rad ??

[abebehrmann]

I would just monitor the temps for a while ... Sand is a hard driving environment ... lots of drag on the drivetrain.

Have you had the issues in the same driving spot in the past ??

Fanclutch is something that ought to be replaced if you are not sure of its age/condition ... and the higher temps in the sand ... might, be an indicator the fanclutch is starting to lose its oomph.

Improving the cooling for the AW4 ... would also be a priority for me - for wheeling in sand.

... you still have the tranny connections to the rad ??

Never been on these particular trails before but never seen it get above 219 in the year I've owned it nor have I since this little expedition.

I wasn't even thinking about tranny temps! I have the oem trans cooler but IIRC the lines still go through the rad(?). Would it be better to fully remove it from the rad and install an aftermarket cooler?

[Carves]

Bypassed the rad and fitted a big cooler on mine.

Tranny temps are much more acceptable ... and going by long term, temp testing I did ... it also seems to have helped - in providing more stable, coolant temps.

Keep in mind of course ... different vehicle results may vary - depending on climate and driving styles .. ;);)

If you decide to make changes ... Id suggest you beg, borrow, or buy, some proper temp gauges, or something like this that can be used as a temp monitor for anything .. http://enginewatchdog.com/index.html,

... and do some before and after comparisons, to see what you ended up with. ... stuff like warm up time variations, min & max temps etc.

[bruggz351]

I've done the same as Carves.
http://i1133.photobucket.com/albums/m596/bruggz351/JEEP/IMAG0368_zpsb4b2d321.jpg

Although, mine stays a little too cool now. I'm looking into fitting a thermostat to run the fluid straight back to the trans until it reaches running temp then opening the thermostat to flow through the cooler.

I'm using mechanical gauges now,
http://i1133.photobucket.com/albums/m596/bruggz351/JEEP/IMAG0354_zps5db17e4d.jpg

:mad:camera flare on the oil temp...
... because I kept having probs with the electric gauges..

[abebehrmann]

Great tips you guys. I already log all my vehicle information with the OBDII app on my phone so I know those temps are generally good but can't monitor the trans temps this way. Going to invest in a transmission temp gauge first to get a good baseline on my average temps, then possibly invest in an aftermarket cooler. What's an acceptable trans temp?

[4.3LXJ]

That is a good question Abe. But basically you want to keep them at about 180°. Bear in mind that currently you are probably trying to cool your tranny in coolant that is around 200° on the cool side of the radiator. Kind of makes you want to wonder what those engineers were thinking. Many of the early XJs had an external cooler that ran across the bottom of the radiator

[Carves]

That is a good question Abe. But basically you want to keep them at about 180°. Bear in mind that currently you are probably trying to cool your tranny in coolant that is around 200° on the cool side of the radiator. Kind of makes you want to wonder what those engineers were thinking. Many of the early XJs had an external cooler that ran across the bottom of the radiator


What really makes you wonder what they thinking,

.... is when you look at the RHD versions ... and they have the tranny lines running to the hot side of the radiator .. :confused:

... tis a great idea for our climate down here .. :rolleyes::rolleyes:


As a guide to temps,

Factory specs for, normal, tranny temps are 122*f - 176*f ... according to the FSM

Measuring the sump temps ... mine floats between 150*f - 170*f, depending on the time of year and driving conditions.