[bwhit63]

Got '14 GC EcoDiesel with weird overheating problem. Cat upgrades completed. In 2015 Colorado trip we went over Raton pass fine then La Veta pass. Got all the way down the pass and headed into Alamosa CO when the engine overheated. Oil and water temps spiked into red zone.

Dealer in Alamosa replaced water pump but couldn't tell me how a mountain pass could destroy a water pump with on 14K miles on engine. There were some codes thrown but did't get them from dealer (I should have!). Finished our trip and went back to flat lands and its been okay until we made another trip to Colorado this week when the exact same thing happened going over Monarch pass.

We made it over Raton pass first, then La Veta pass next, but it overheated at the bottom of Monarch pass - not going up or cruising down. We limped into Gunnison and pulled codes U0100 (lost comm with ECM/PCM) and P0197 (Engine Oil Temp Sensor Low).

I reset the codes by disconnecting battery then laid over in Gunnison for the night. Then tried to make it to Montrose where there is a Jeep dealer. It was cold morning and we made it only a few miles and temps spiked again. Check engine light came on again. Called tow truck and got it over to the Jeep dealer in Montrose.

Dealer in Montrose thinks its a stuck thermostat. Getting thermostat replaced tomorrow but don't see how those codes relate to a thermostat or a water pump 2 years ago. We now have 45K miles.

Any ideas how a going over a mountain pass 2 year apart triggers the same overheating problem but one dealer says water pump and another says thermostat but neither relate to codes?

 

[bwhit63]

Forgot to mention: in both cases, I've suspected the quick/extreme altitude change as a trigger to a sensor problem. Is it plausible that confused sensors would prevent the cooling system from working correctly?

 

[CaseyGV]

Just another data point - I live in Denver and have driven into the mountains many times with my 14 GC and it has never once come close to overheating. I've actually driven over Raton Pass with it (a drive from Denver to Tucson and back) and it was fine. I have seen the water temp needle get just north of the center going up I-70 during a summer day, but usually it comes right back down.

 

[bwhit63]

Got it figured out. It is weird tho. Called the Alamosa dealer and they told me it threw code P0197 as well back in 2015. Besides the water pump, all they did was flash new firmware.

There was no new firmware updates, so I told the Montrose dealer to reprogram all the modules and forget the thermostat on the hunch the control modules were confused by the rapid changes in altitude.

It worked! We came over several small passes going to Lake City and no overheating. It behaved like the other posts I read that described normal fluctuations under load.

Resetting the modules by disconnecting battery did not work as mentioned earlier. It took a full reprogramming.

Since it happened twice, I suspect it can happen again. But I'm going to maintain higher revs via paddle shifters going over the passes in the future to see if it helps prevent it from occurring again.

 

[Brewster]

Sounds like you found a dealer that can properly 'troubleshoot' vs just 'throwing parts on' costing $$$$!

 

[Casper2]

Somewhere along the line I saw mention to a faulty radiator cap causing overheating. I googled it and it appears that this has presidence. If I ever have this problem the first thing I plan on doing is feplacing the cap. I'm not saying it will fix it..... It's just that dealers use troubleshooting flow charts that do not take into account cost. Me....? I go cheapest first. Caps are cheap.

 

[BDSsr]

bwhit63 stated that he used the shifting paddles to maintain higher RPMs. What RPMs are you comfortable with? thanks

 

[RZRMan]

I too had an overheating problem with my 2014 GC diesel while on the way to Lake City on Monarch Pass. I had towed my RZR up the pass twice before and the temperature rarely went much over the center mark. On this trip the needle suddenly went to Hot and I lost all of my coolant near the top of the pass. I got it cooled down, refilled it and made it into Lake City although it ran very hot. In Lake City I bled the air out and on the drive back to Iowa it would get very close to overheating but did not hit the red mark.

In Iowa my Jeep dealer flushed the system, installed a new water pump, thermostat, and radiator cap. That was a year ago and I have noticed ever since it seems to run warmer than it did, just slightly above the center mark - this in the flatlands of Iowa! The dealer never said anything about codes and I am wondering if I need to have the control modules re-programmed? -- Steve

 

[RZRMan]

Got it figured out. It is weird tho. Called the Alamosa dealer and they told me it threw code P0197 as well back in 2015. Besides the water pump, all they did was flash new firmware.

There was no new firmware updates, so I told the Montrose dealer to reprogram all the modules and forget the thermostat on the hunch the control modules were confused by the rapid changes in altitude.

It worked! We came over several small passes going to Lake City and no overheating. It behaved like the other posts I read that described normal fluctuations under load.
Resetting the modules by disconnecting battery did not work as mentioned earlier. It took a full reprogramming.

Since it happened twice, I suspect it can happen again. But I'm going to maintain higher revs via paddle shifters going over the passes in the future to see if it helps prevent it from occurring again.

Finally getting around to doing something as we are heading to Colorado. When I take the Jeep to the dealer all I need to do is to tell them "reprogram all modules"? The service writer was a bit confused about what I meant. Should they reprogram all modules are just specific ones? Thanks! Steve

 

[1bajaboy]

Got '14 GC EcoDiesel with weird overheating problem. Cat upgrades completed. In 2015 Colorado trip we went over Raton pass fine then La Veta pass. Got all the way down the pass and headed into Alamosa CO when the engine overheated. Oil and water temps spiked into red zone.

Dealer in Alamosa replaced water pump but couldn't tell me how a mountain pass could destroy a water pump with on 14K miles on engine. There were some codes thrown but did't get them from dealer (I should have!). Finished our trip and went back to flat lands and its been okay until we made another trip to Colorado this week when the exact same thing happened going over Monarch pass.

We made it over Raton pass first, then La Veta pass next, but it overheated at the bottom of Monarch pass - not going up or cruising down. We limped into Gunnison and pulled codes U0100 (lost comm with ECM/PCM) and P0197 (Engine Oil Temp Sensor Low).

I reset the codes by disconnecting battery then laid over in Gunnison for the night. Then tried to make it to Montrose where there is a Jeep dealer. It was cold morning and we made it only a few miles and temps spiked again. Check engine light came on again. Called tow truck and got it over to the Jeep dealer in Montrose.

Dealer in Montrose thinks its a stuck thermostat. Getting thermostat replaced tomorrow but don't see how those codes relate to a thermostat or a water pump 2 years ago. We now have 45K miles.

Any ideas how a going over a mountain pass 2 year apart triggers the same overheating problem but one dealer says water pump and another says thermostat but neither relate to codes?

Was the water pump bad? Is the thermostat bad? Is a mechanic doesn't know how to test a thermostat find a new mechanic. If the water pump wasn't bad and that wasn't the problem if the thermostats not bad that's not the problem is mechanics nowadays don't know a screwdriver from a wrench

 

[RZRMan]

The Jeep dealer said that the water pump & thermostat were OK. I changed the thermostat, coolant and radiator cap. I was intrigued by your solution with the modules as it sounded like what happened to me. Trouble is, here in the flats in Iowa the temperature is normal to just slightly higher. Going to head to Colorado in a month or so and that is when the problem would show up. Thought this might just be something to do before I go and looking for your feedback. Does that make sense?