Overheating issues

[red87]

It's a common issue with a lot of rigs, not just mitsu's. It's why the aftermarket radiator market is doing well.

Ha, fair enough.

I'll start looking into these ideas things next week when I have some time.

[m3at333hp]

Speaking of overheating issues, I have a question:

My A/T light comes on while wheeling, and it is not low or anything. I have just recently done a flush and use Mobil1. I should note, it did this before the flush also in Cleghorn. It only comes on while wheeling. So, could a filter cause this (even though it is just a mesh filter)? I doubt a clog in the tranny cooler since the oil is not that thick. Bad torque converter? Bad sensor? I will check if oil has turned brown tonight.

[off-roader]

Speaking of overheating issues, I have a question:

My A/T light comes on while wheeling, and it is not low or anything. I have just recently done a flush and use Mobil1. I should note, it did this before the flush also in Cleghorn. It only comes on while wheeling. So, could a filter cause this (even though it is just a mesh filter)? I doubt a clog in the tranny cooler since the oil is not that thick. Bad torque converter? Bad sensor? I will check if oil has turned brown tonight.

I'd send a sample of the oil off for analysis just to be 110% sure it's not harming your transmission. But that said, it's likely due to the hot temps and reduced airflow at slow speeds. Have you done the AC fan mod to allow you to turn it on w/out running the AC so it allows you to better cool your fluids?

[mike5]

The timing on this thread is perfect. I can add some light to these two questions. So a couple of months ago, I went Coyote Flats in the Eastern Sierras. We ended up around 10,000 feet. When we went the weather was cold (probably around 50 during the day and down to 25 at night). While on a slow/long/steep ascend my coolant temp started rising and my AT light came on. So I pulled over and gave the car a break. Later on while stationary after some slow 4low stuff, again it started climbing.

I had serviced the cooling system so I was a bit surprised. It never happened to me on the streets. But something I'd notice occasionally was stains on the expansion tank...meaning some fluid and over flowed. After my trip, I had the mechanic go through the cooling system. The issue was the thermostat. It was "sticking." But they only figured this out by removing it and testing in hot water. After changing it, I went on another trip with a lot of climbing in 85+ weather. No a single cooling issue. In my case I knew the radiator was good, it had been flushed, cracked fan replaced and coolant drained. So not hard to figure that one out.

With respect to the AT light, my educated guess is this: at higher elevation while off roading and very slow speeds, if you leave the car in drive it will usually use a higher gear than it should. This results in more torque converter slippage (by design) which generates heat. Instead if you deliberately use 1st and 2nd gear, then slippage is eliminated which reduces heat. On trips where I've done this, I had zero issues.

[red87]

Sticking thermostat was my best guess too. Hopefully I'll find some time next week to test it. That AC fan mod is a good idea though. I do have an unused switch now that I am on OME suspension...

[mike5]

Quick question: how did you run wires from the engine compartment through the firewall into the interior?

[tyty13]

The timing on this thread is perfect. I can add some light to these two questions. So a couple of months ago, I went Coyote Flats in the Eastern Sierras. We ended up around 10,000 feet. When we went the weather was cold (probably around 50 during the day and down to 25 at night). While on a slow/long/steep ascend my coolant temp started rising and my AT light came on. So I pulled over and gave the car a break. Later on while stationary after some slow 4low stuff, again it started climbing.

I had serviced the cooling system so I was a bit surprised. It never happened to me on the streets. But something I'd notice occasionally was stains on the expansion tank...meaning some fluid and over flowed. After my trip, I had the mechanic go through the cooling system. The issue was the thermostat. It was "sticking." But they only figured this out by removing it and testing in hot water. After changing it, I went on another trip with a lot of climbing in 85+ weather. No a single cooling issue. In my case I knew the radiator was good, it had been flushed, cracked fan replaced and coolant drained. So not hard to figure that one out.

With respect to the AT light, my educated guess is this: at higher elevation while off roading and very slow speeds, if you leave the car in drive it will usually use a higher gear than it should. This results in more torque converter slippage (by design) which generates heat. Instead if you deliberately use 1st and 2nd gear, then slippage is eliminated which reduces heat. On trips where I've done this, I had zero issues.

You can ADD a 2nd AT cooler

[mike5]

Sure thing there. I'd rather add a fan to the cooler than place a second one.

[m3at333hp]

I'd send a sample of the oil off for analysis just to be 110% sure it's not harming your transmission. But that said, it's likely due to the hot temps and reduced airflow at slow speeds. Have you done the AC fan mod to allow you to turn it on w/out running the AC so it allows you to better cool your fluids?

No, I will look around for that mod. I might also find a bigger A/T cooler. Both times this happened, I was at Cleghorn and the temps outside were not that high.

[m3at333hp]

With respect to the AT light, my educated guess is this: at higher elevation while off roading and very slow speeds, if you leave the car in drive it will usually use a higher gear than it should. This results in more torque converter slippage (by design) which generates heat. Instead if you deliberately use 1st and 2nd gear, then slippage is eliminated which reduces heat. On trips where I've done this, I had zero issues.

Mike, I will try putting it in a lower gear next time. Thanks!