2005 Liberty 3.7 overheating

[05Mitchell]

So I was just recently given this Liberty. It was driven from Pennsylvania to here in Las Vegas and it did great on the trip. We took a trip to downtown, which was about 20 minutes away. It was good on the way there but about 15 minutes into the drive back and the temperature gage started climbing so I turned the heat on and it came back down, it was still under the 3/4 mark at its warmest but definitely would have kept climbing without turning the heat on. So I started with trying to replace the thermostat. I got one from autozone, and it still overheated. After reading through the threads I decided to buy a thermostat from the dealership. I got it and it was branded MotoRad. Sales rep told me they no longer supply mopar branded thermostats but I verified the thermostats worked and even tried running it with no thermostat and it still overheated so I think I've ruled that out. I bled the air out of the cooling system. With doing all that, I've drained and refilled the coolant 4 times so far only using HOAT coolant. My father in law, former CJD mechanic said he had just recently put in a water pump (Gates brand). I also power probed the electric fan, this vehicle does not have a mechanical fan, and found the high side of the fan to not work so I also replaced that, and still it overheats. There is no signs of a head gasket failure, no oil in the coolant and vice versa however I have not totally ruled it out. It seems to really only happen with the A/C on. The heater hoses are both warm. I have not totally verified the condition of the radiator but it seems fairly new and I know for sure it's only had HOAT coolant in it. This is the first Jeep I've ever had or worked on so I figured I'd come on here to ask people with more experience with these. Any advice or suggestions? Thanks in advanced.

 

[RenKJ]

I can't advise on how to solve it but I can warn not to let it overheat at all, shut down if you need to

overheating is the main thing that can kill these engines

 

[05Mitchell]

I can't advise on how to solve it but I can warn not to let it overheat at all, shut down if you need to

overheating is the main thing that can kill these engines

Yeah that's something I've seen a lot on here. It has never been above the 3/4 mark and im no longer driving it until I can figure it out. Thank you very much for your response

 

[KJowner]

The AC adds a lot of heat to the stack of heat exchangers. If your radiator is part blocked or the water pump isn't working like it should then you could get the problem you describe.
The best way to get the head gasket ruled out is find a garage with a test kit who can see if there's any exhaust gas in the cooling circuit, shouldn't cost much to get more done.

 

[Glenn Dickson]

So I was just recently given this Liberty. It was driven from Pennsylvania to here in Las Vegas and it did great on the trip. We took a trip to downtown, which was about 20 minutes away. It was good on the way there but about 15 minutes into the drive back and the temperature gage started climbing so I turned the heat on and it came back down, it was still under the 3/4 mark at its warmest but definitely would have kept climbing without turning the heat on. So I started with trying to replace the thermostat. I got one from autozone, and it still overheated. After reading through the threads I decided to buy a thermostat from the dealership. I got it and it was branded MotoRad. Sales rep told me they no longer supply mopar branded thermostats but I verified the thermostats worked and even tried running it with no thermostat and it still overheated so I think I've ruled that out. I bled the air out of the cooling system. With doing all that, I've drained and refilled the coolant 4 times so far only using HOAT coolant. My father in law, former CJD mechanic said he had just recently put in a water pump (Gates brand). I also power probed the electric fan, this vehicle does not have a mechanical fan, and found the high side of the fan to not work so I also replaced that, and still it overheats. There is no signs of a head gasket failure, no oil in the coolant and vice versa however I have not totally ruled it out. It seems to really only happen with the A/C on. The heater hoses are both warm. I have not totally verified the condition of the radiator but it seems fairly new and I know for sure it's only had HOAT coolant in it. This is the first Jeep I've ever had or worked on so I figured I'd come on here to ask people with more experience with these. Any advice or suggestions? Thanks in advanced.

MY 2006 Liberty CRD had a large buildup of dirt, dead insects and other crap in between the A/C condenser and the radiator that built up over 19 years. The rad was pulled to clean it out and it ran cooler and the A/C cooled much better afterwards.

 

[ikuo78]

Some unlikely causes include the following:

- Fuel is lean due to a failure of the O2 sensor or injector.
→ The fuel trim value can be checked with OBD2.

- Sludge has accumulated on the piston head, causing the compression ratio to be high.
→ This can be checked with a fiberscope through the plug hole.

- The PCV valve is clogged and the crankcase cannot be ventilated.
→ If I remember correctly, the recommended replacement interval is 30K miles.

・Increased load due to A/C compressor failure.
→It is likely that idling will become unstable when the A/C clutch is operating.

Incidentally, all KJs sold in Japan, which has summer temperatures exceeding 35°C (95°F) and urban areas with heavy traffic congestion, had mechanical fans.

 

[KJowner]

MY 2006 Liberty CRD had a large buildup of dirt, dead insects and other crap in between the A/C condenser and the radiator that built up over 19 years. The rad was pulled to clean it out and it ran cooler and the A/C cooled much better afterwards.

Good point, had a look at mine, the radiator and condenser gap was clean, but the t ransmission oil cooler to condenser gap was full of leaves and straw!

You must be registered for see images attach

Cleaned it out quickly with a hose and the lid off some plastic conduit, I'll have to pull it to bits for a thorough job another day.

 

[u2slow]

One of the water pumps I replaced had a plastic impeller and it was ready to disintegrate. Might be worth a check....

 

[eldredg]

So I was just recently given this Liberty. It was driven from Pennsylvania to here in Las Vegas and it did great on the trip. We took a trip to downtown, which was about 20 minutes away. It was good on the way there but about 15 minutes into the drive back and the temperature gage started climbing so I turned the heat on and it came back down, it was still under the 3/4 mark at its warmest but definitely would have kept climbing without turning the heat on. So I started with trying to replace the thermostat. I got one from autozone, and it still overheated. After reading through the threads I decided to buy a thermostat from the dealership. I got it and it was branded MotoRad. Sales rep told me they no longer supply mopar branded thermostats but I verified the thermostats worked and even tried running it with no thermostat and it still overheated so I think I've ruled that out. I bled the air out of the cooling system. With doing all that, I've drained and refilled the coolant 4 times so far only using HOAT coolant. My father in law, former CJD mechanic said he had just recently put in a water pump (Gates brand). I also power probed the electric fan, this vehicle does not have a mechanical fan, and found the high side of the fan to not work so I also replaced that, and still it overheats. There is no signs of a head gasket failure, no oil in the coolant and vice versa however I have not totally ruled it out. It seems to really only happen with the A/C on. The heater hoses are both warm. I have not totally verified the condition of the radiator but it seems fairly new and I know for sure it's only had HOAT coolant in it. This is the first Jeep I've ever had or worked on so I figured I'd come on here to ask people with more experience with these. Any advice or suggestions? Thanks in advanced.

1) My 2003 KJ had overheating issue using AC. The problem was the relay failed for the high speed on the electric cooling fan. So not only the fan, but a relay and fuse can fail. As I understand, whenever the AC is turned on, the KJ should switch to high speed on the cooling fan. 2) Had a minor overheating problem due to coolant loss from a failing water pump leak, but that showed up in a line of white from evaporated coolant under the hood and to the sides of the accessory belt. 3) Be cautious of trusting the temp gauge for engine temp. Many KJs go to half and stay there, even when the coolant has overheated. 4) The mechanical fan, clutch and shroud were part of the optional heavy duty cooling system for towing. Base model KJs came with only the electric fan. Some folks actually run fine with just the mechanical system when the electric fan fails, if they have mechanical.. Recyclers can often supply the mechanical system parts. But, the connector electric plugs on some fans of different years are different, so not necessarily plug and play.

 

[Krf]

Either the electric radiator fan isn't working or the mechanical radiator fan clutch is bad. Either of them malfunctioning will cause the vehicle to overheat. I determined the fan clutch was bad on my 2003 Liberty and replaced it. That fixed my problem until I was stuck at a long stoplight on a hot day with the A/C on, and the vehicle started to overheat again. When I went back under the hood I discovered that I forgot to plug the electric fan back into the connector. After I reconnected it, everything worked fine.

If the thermostat was bad, the vehicle would overheat real fast with the A/C off. Same with a bad water pump. Everyone here is overthinking the problem and missing the obvious: The vehicle overheats easily when either of the two fans are not working.

One other thing: The electric fan relay could be bad and cause the electric fan to not work. However, when that happened with my Liberty, it threw a fault code that was easily diagnosed with a scanner.

 

[Ikster]

I replaced the electric fan and tested it by jumping the relays. The fan ran at both high and low speeds. So I started it up and turned on the ac and reaiized I had not been hearing the fan before. Took it for a test drive in heavy traffic, stop and go and 50-60 mph and it stayed at the proper temp and ac was cold. FIXED IT!!! Thanks everyone.

 

[slingworks]

I'm glad you fixed it a month ago Ikster.

I only just saw your thread, so I'm going to post my experiences.

I've owned (still) exactly 2 Liberties, both '05 models with the 3.7 and 42RLE trans....

One is a RHD and I used it for 3 years on a Rural Route, so it saw a different kind of use than my LHD "civil" use Liberty.

The mail jeep constantly overheated in hot summer months in certain places. Mainly where there were lots of hills and lots of stops uphill during the early afternoon. It came to me from the flatlands of SC and it only had the electric fan unit. The fan worked fine, but was inadequate when it got hot. I had to resort to installing the mechanical fan alongside of the electric fan to keep the heat under control.

Problem solved.

I would not own a liberty without a mechanical fan installed. The electric fans are somewhat anemic and inadequate and seem prone to failure. You need to add a mechanical fan to yours! Look on ebay.

 

[u2slow]

The mail jeep constantly overheated in hot summer months in certain places. Mainly where there were lots of hills and lots of stops uphill during the early afternoon. It came to me from the flatlands of SC and it only had the electric fan unit. The fan worked fine, but was inadequate when it got hot. I had to resort to installing the mechanical fan alongside of the electric fan to keep the heat under control.

Problem solved.

I would not own a liberty without a mechanical fan installed. The electric fans are somewhat anemic and inadequate and seem prone to failure. You need to add a mechanical fan to yours! Look on ebay.

That's most definitely an auto trans 'feature' - they make heat.

Our manual trans '05 engine temp comes up to 12:00 position and is unwavering , even after long hours plugging around offroad in the mountains.

 

[KJlibertyBR]

minha KJ 3.7 2006 possui a ventoinha elétrica e mecanica. Porem acredito que a elétrica esteja com defeito. Qual temperatura ela deve acionar o 1º e 2º estagio?

 

[slingworks]

Check to make sure your thermostat is properly installed as well. Seems like I remember that some aftermarket thermostats can be installed incorrectly. On a cool day you can get away with it, on a hot day with AC you wont.