Mechanics--Jeep JK issue

[Chew]

Google is throwing out too many options. Wanted to see if any of you have dealt with this specific issue.

2009 Jeep JK Wrangler/Rubicon with the 3.8L mini-van motor.

Drives fine with no issues. But starts to run hot at idle and temp gauge starts climbing. Coolant levels are good. AC blows hot when this issue happens. Doesn't happen while driving. Just idling/parked.

Anyone had this problem and figured it out?

Thanks.

[Walker]

Electric fan or belt driven fan. If belt driven I'm thinking fan clutch.

[Twist]

Sounds like a coolant circulation issue. Possible partially plugged radiator or thermostat not opening all the way.

I say that because when driving, the airflow will naturally help with the cooling somewhat.

[Chew]

Electric fan or belt driven fan. If belt driven I'm thinking fan clutch.

I was told to turn the fan by hand and see if it felt like it was hard to turn or if it spun freely. If hard to turn, fan clutch was out. But it turned freely. Not saying that's not the problem...just something I tried.

[Walker]

I was told to turn the fan by hand and see if it felt like it was hard to turn or if it spun freely. If hard to turn, fan clutch was out. But it turned freely. Not saying that's not the problem...just something I tried.

And if its oily on the back the clutch is bad.

[Charlie80]

My TJ was doing the same thing and it turned out the thermostat was broken and was stuck about halfway open.

[Burnadell]

Sounds like a coolant circulation issue. Possible partially plugged radiator or thermostat not opening all the way.

I say that because when driving, the airflow will naturally help with the cooling somewhat.

I agree with this. The thermostat may not be opening (need to replace) and/or the radiator may need flushing.

[Kingfisher789]

Does it have an electric cooling fan? I think it does and should be running on low speed with the ac on.

[knighttime]

Thermostat

[dbaio1]

My bet is auxiliary fan or thermostat. Good luck Bobby my vehicle started doing the same thing ended up being low on coolant due to pin hole leak I coolant reservoir. They are proud of those little plastic jugs $$$

[Chew]

Thanks guys.

[Chew]

Might have found a crazy fix on youtube. Found a guy that says that the Jeep is prone to get air bubbles in the radiator and the lines and it's really not holding as much coolant as you think. So the guy says to park the Jeep on an incline with the engine higher than the rest of the Jeep and open up the radiator. When I did it a bunch of air shot out and then I started filling it with coolant slowly as the bubbles came up and the air came out. When I got the coolant filled I put the cap back on. Tried to make it overheat and so far so good. I'll test it out better tomorrow with a long drive and a long idle.

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[Texas Grown]

Might have found a crazy fix on youtube. Found a guy that says that the Jeep is prone to get air bubbles in the radiator and the lines and it's really not holding as much coolant as you think. So the guy says to park the Jeep on an incline with the engine higher than the rest of the Jeep and open up the radiator. When I did it a bunch of air shot out and then I started filling it with coolant slowly as the bubbles came up and the air came out. When I got the coolant filled I put the cap back on. Tried to make it overheat and so far so good. I'll test it out better tomorrow with a long drive and a long idle.

sent via Tapatalk boooooy

Cooling system vacuum kits can be pretty cheap, or expensive, pending where you get one. I was going to recommend doing what you did in this post. Or getting a cooling system vacuum kit. Course, making sure your thermostat, fans, hoses, and water pump are all in good working order before going to a "cooling system air pocket". Newer motors tend to get them in the blocks. Sometimes in the heater core too. Some of the older late modle V-8s did this also.

Edit: and it's taken me most of 30 minutes to get this post to post.