3.6 Radiator Fan

The BAD Influence · Jun 18, 2020

My Jeep runs hot. Not just on hill climbs but even on the freeway if I hold it at 3000 rpms for too long. Last night on a local Jeep Facebook page there was a discussion about the fans not working properly. Apparently it's a common problem. The fan will kick on at 225° and seem to run fine, but just isn't spinning fast enough to pull enough air through. I've replaced the radiator and thermostat, with no change. Is this fan issue really that common? It's an easy, but expensive fix. Any ideas or thoughts?
Thanks

nbunga · Jun 18, 2020

krdadlamb said:
My Jeep runs hot. Not just on hill climbs but even on the freeway if I hold it at 3000 rpms for too long. Last night on a local Jeep Facebook page there was a discussion about the fans not working properly. Apparently it's a common problem. The fan will kick on at 225° and seem to run fine, but just isn't spinning fast enough to pull enough air through. I've replaced the radiator and thermostat, with no change. Is this fan issue really that common? It's an easy, but expensive fix. Any ideas or thoughts?
Thanks

Is there anything blocking airflow to your grille, like a winch, decorative grill inserts, bull bar or anything? That’s been a problem for a few guys on here before.

Ddays · Jun 18, 2020

The 3.6's run pretty hot and a lot has to do with the emissions. Even so, running hotter than normal hasn't seemed to really affect the life of them. My '12 Durango with the same engine/tranny combination runs considerably cooler
than the Jeep.

The BAD Influence · Jun 18, 2020

nbunga said:
Is there anything blocking airflow to your grille, like a winch, decorative grill inserts, bull bar or anything? That’s been a problem for a few guys on here before.

Winch. But that's been on since the Jeep was a couple months old. Biggest difference changed after gears and lockers. 37s, so I went with 5.13. 3000 rpms at 75 mph.

Ddays · Jun 18, 2020

krdadlamb said:
Winch. But that's been on since the Jeep was a couple months old. Biggest difference changed after gears and lockers. 37s, so I went with 5.13. 3000 rpms at 75 mph.

So is it running hotter than it used to?

The BAD Influence · Jun 18, 2020

Ddays said:
So is it running hotter than it used to?

Yes. Before gears the needle would occasionally move past half way, maybe to 2/3s. Now it regularly hits 3/4.

A.J. · Jun 18, 2020

krdadlamb said:
Yes. Before gears the needle would occasionally move past half way, maybe to 2/3s. Now it regularly hits 3/4.

Just a thought. Have you verified that the gauge is correct?

Sent from my iPhone using WAYALIFE mobile app

Weebz · Jun 18, 2020

Had you done anything with the coolant system prior to or around the time you did gears?

The BAD Influence · Jun 19, 2020

A.J. said:
Just a thought. Have you verified that the gauge is correct?

Sent from my iPhone using WAYALIFE mobile app

I don't know how to check the gauge for accuracy, other than just replacing the sending unit. A friend was having all kinds of problems with his and that was the fix. But he has the 3.8

The BAD Influence · Jun 19, 2020

Weebz said:
Had you done anything with the coolant system prior to or around the time you did gears?

Yes. Replaced the radiator and thermostat. I've had the dealership flush the system twice, thinking there's maybe still some air in there. It never blows any antifreeze out, and the de gas bottle is always right at full level.

CalSgt · Jun 19, 2020

krdadlamb said:
Yes. Replaced the radiator and thermostat. I've had the dealership flush the system twice, thinking there's maybe still some air in there. It never blows any antifreeze out, and the de gas bottle is always right at full level.

Thermostat with a different temp range or defective thermostat could cause that I think...

Mile High JK · Jun 19, 2020

krdadlamb said:
Winch. But that's been on since the Jeep was a couple months old. Biggest difference changed after gears and lockers. 37s, so I went with 5.13. 3000 rpms at 75 mph.

This is the exact same thing that happened to me. Temp gauge never really moved past halfway. Went to 37s and 5.13 gears started to get higher temps. Mine gauge only moves when going up longer steeper hills though. Gets up to the 3/4 mark. A local 4x4 shop told me not worry about it. He said it was common with the larger tires and gears at elevation. :thinking:

Ddays · Jun 19, 2020

Mile High JK said:
This is the exact same thing that happened to me. Temp gauge never really moved past halfway. Went to 37s and 5.13 gears started to get higher temps. Mine gauge only moves when going up longer steeper hills though. Gets up to the 3/4 mark. A local 4x4 shop told me not worry about it. He said it was common with the larger tires and gears at elevation. :thinking:

Mine did the same thing and I really started noticing it when I drove through Colorado on 70. Temp went up to the 3/4 mark on every hill but never went past it. I finally quit worrying about it. I've never overheated in it either.

jeeeep · Jun 19, 2020

My 2010 JK did the same thing, was fine for a long time with 4.88, 37's, beadlocks and winch; then it starting running hotter.

Replaced the water pump helped it a little but I noticed that turning off the AC would drop it back into normal range.

I had the AC checked, they found a leak, fixed it an it's been back to normal again.

The BAD Influence · Jun 20, 2020

Thanks for the feedback. A friend with almost the same build is seeing the same temps. Guess other than swapping out the bumper with one that will drop the winch down away from the grill, there's not much to worry about.

The BAD Influence · Jun 26, 2020

Update:
I took it back to the dealership, one more try at flushing the radiator. Thinking there has to be air in the system. They called and said they did a pressure test, and there's a blown head gasket. Got 6 months left on the warranty so they're taking care of it.

HighwayTrout · Jun 26, 2020

krdadlamb said:
Update:
I took it back to the dealership, one more try at flushing the radiator. Thinking there has to be air in the system. They called and said they did a pressure test, and there's a blown head gasket. Got 6 months left on the warranty so they're taking care of it.

Thats a bummer. Good thing you were paying attention and kept after it. Could have got ugly and real expensive if you blew it off.

Weebz · Jun 26, 2020

krdadlamb said:
Update:
I took it back to the dealership, one more try at flushing the radiator. Thinking there has to be air in the system. They called and said they did a pressure test, and there's a blown head gasket. Got 6 months left on the warranty so they're taking care of it.

I’d say that’s a bummer but damn you got lucky that it got caught with 6 months left!

Mile High JK · Jun 26, 2020

krdadlamb said:
Update:
I took it back to the dealership, one more try at flushing the radiator. Thinking there has to be air in the system. They called and said they did a pressure test, and there's a blown head gasket. Got 6 months left on the warranty so they're taking care of it.

Glad they found that! Will be interested to see if that completely fixes the temps from going up.

Primo82 · Jun 26, 2020

krdadlamb said:
Update:
I took it back to the dealership, one more try at flushing the radiator. Thinking there has to be air in the system. They called and said they did a pressure test, and there's a blown head gasket. Got 6 months left on the warranty so they're taking care of it.

Happy they found that for you under warranty!

3.6 Radiator Fan

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