05 3.7 overheating in stop-and-go traffic

[05KJDalton]

i’ve been having this weird issue with my 2005 3.7 where if i sit still after the vehicle has warmed up, or if i’m in stop and go traffic while up to temperature, it will start to over heat. i’ve noticed my cooling fan isn’t kicking on in front at all unless i turn on my A/C. it did this for about 2 weeks last summer as well, but seemed to fix itself. i already replaced the radiator and the A/C compressor as a unit previously. before having the issue the radiator was replaced. and the compressor was replaced in November of 2017. it is my daily driver and i can’t keep having it do this. turning on the heat at full blast helps bring it down to just over the halfway mark at a stop. please help!

EDIT: problem was solved today. it was the cooling fan. it had stopped working. replaced it today.

 

[Damotee]

My Jeep would do something similar last year. The fault for me was with the electric fan. It wasnt working. I have the HD Cooling system as well though, which allowed me to keep driving it with no e-fan.
So, driving with the A/C on would cause the temp to rise because the e-fan wasnt doing its job, as would sitting in traffic (with the A/C on).
As soon as i turned off the A/C, the temp would drop. I guess the clutch fan on the HD pack was sufficient to cool it with no a/c on.
I bought a new electric fan and its fine again. Mine has the 3 prong connector.

I also had to turn the heat on to help cool it down. Not fun in the Aussie summer i can tell ya.

 

[05KJDalton]

mine overheats if i sit in traffic or sit idle. or sit in a drive thru. but i’ve learned a little trick until i can get it fixed; if i turn on my A/C sitting at a light or whatever i may be doing sitting idle for a while, it doesn’t overheat because the fan kicks on and keeps it cool. the a/c blows almost heater hot air, but the temp stays cool and stable.

 

[Damotee]

It sounds like your e-fan isnt working on its own unless you force it to work by turning on the a/c. I reckon you need a new fan. Theyre a piece of cake to install.

 

[ltd02]

mine overheats if i sit in traffic or sit idle. or sit in a drive thru. but i’ve learned a little trick until i can get it fixed; if i turn on my A/C sitting at a light or whatever i may be doing sitting idle for a while, it doesn’t overheat because the fan kicks on and keeps it cool. the a/c blows almost heater hot air, but the temp stays cool and stable.

Seems like if it comes on with the AC then the fan MAY be ok. Have you checked the two relays?

 

[Myke]

Just be cautious about driving it and letting it overheat. Being your daily driver this can be a big issue when the head drops a valve seat and destroys your motor.

These heads are notorious for this. Once you see the temp gauge moving you're already over heating. It's not a linear throw so you won't see it move until ~230 degrees.

 

[05KJDalton]

i haven’t. i’m replacing the fan and the relays tomorrow though.

 

[05KJDalton]

Just be cautious about driving it and letting it overheat. Being your daily driver this can be a big issue when the head drops a valve seat and destroys your motor.

These heads are notorious for this. Once you see the temp gauge moving you're already over heating. It's not a linear throw so you won't see it move until ~230 degrees.

i’m actually replacing the fan and the relays tomorrow after work to see if that’s the issue. hopefully that’s the problem

 

[nohitter64]

I started overheating today. Unfortunately I heard an alarm but nothing lit up on the dash. It repeated and then I saw steam coming from the hood and pulled over. Everything was running and coolant was coming from the overflow. The temp gauge was pegged and then came down to 3/4 as I sat with the a/c on and temp dial to hot. Was able to get it parked for 2 hours before driving it again.If I stayed under 50 mph the temp needle stayed at 12:00. If I ran faster than that it would climb. Good news is the heat seems to be working again so maybe it cleared the heater core.