Temp Gauge Fluctuation
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JK Newbie
Joined: Dec 2012
Posts: 10
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From: Monrovia, California
Temp Gauge Fluctuation
Just picked up an 07 Wrangler Rubicon Unlimited. I've been drivin it around town a bit. But today I noticed that after a long freeway drive (and some stop and go in traffic) the temp gauge began to rise as I sat idle waiting for food in a drive-thru. I turned on the heater which seemed to slowed it down. Once I got back on the road it returned to its usual position at center. Any thoughts on this? Links to the right thread would be helpful. Thanks!
JK Junkie
Joined: Dec 2008
Posts: 2,191
Likes: 6
From: Boston, MA
Just picked up an 07 Wrangler Rubicon Unlimited. I've been drivin it around town a bit. But today I noticed that after a long freeway drive (and some stop and go in traffic) the temp gauge began to rise as I sat idle waiting for food in a drive-thru. I turned on the heater which seemed to slowed it down. Once I got back on the road it returned to its usual position at center. Any thoughts on this? Links to the right thread would be helpful. Thanks!
Sounds like lack of airflow over the radiator while you idle. These radiators are infamous for clogging up with mud, if there are signs of mud up there give it a good hosing off. Note that the radiator is behind the condenser.
Welcome to the forum!
JK Enthusiast
Joined: Aug 2011
Posts: 436
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From: Lima, ny
Originally Posted by Jiblet
Check the radiator for mud / debris, check that the fan is working properly, check the coolant level.
Sounds like lack of airflow over the radiator while you idle. These radiators are infamous for clogging up with mud, if there are signs of mud up there give it a good hosing off. Note that the radiator is behind the condenser.
Welcome to the forum!
JK Enthusiast
Joined: Oct 2011
Posts: 230
Likes: 0
From: Doylestown
If it's going up a lot you might have a sticking thermostat. I don't know about the 3.8 or 3.6 but usually that is a pretty cheap and easy replacement. I think they are usually less than $20 and take a hour or so to replace.
JK Freak
Joined: Mar 2011
Posts: 791
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From: Vancouver, BC
It's your fan not working. You can drive without a fan, especially on highway, but when you stop, there is no airflow, and that's when the fan comes in most. You can test your fan by connecting a couple jumper wires to pos+ and neg- connections on the fan. If it fires up, then it's fine. Something BEFORE the fan is at fault then. Look for a fan switch or something that controls fan activation. I'm not sure what these Jeeps have for that. Also, it could be that your coolant temperature sensor isn't working right, but you'd probably get a check engine light for that.
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JK Newbie
Joined: Dec 2012
Posts: 10
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From: Monrovia, California
Thanks for all the replys 
:
-Coolant levels look good.
-Tried washing off the radiator, though it looks clean already. But I may need some advice on how to do it properly. Since the fan housing is on how would i clean the radiator from the back? Should I remove it? Is it ok to spray water from inside the engine compartment through the fan?
-All the fins look okay. I wouldn't say that they are too excessively bent beyond normal (from rocks and stuff).
- Since I'm still getting used to all the sounds this Jeep makes. I think the fan is turning on but I'll check again tomorrow when I have some time. And can watch with the hood up. (at work now). I'll keep you posted. Thanks again!
:
efan450
Quote Originally Posted by Jiblet
Check the radiator for mud / debris, check that the fan is working properly, check the coolant level.
Sounds like lack of airflow over the radiator while you idle. These radiators are infamous for clogging up with mud, if there are signs of mud up there give it a good hosing off. Note that the radiator is behind the condenser.
Welcome to the forum!
Yup, i Agree. I will also add be sure to wash the radiator from the back side forward so you push the debris out the way it came in. And every jk I've seen with the 3.8(mine included) the temp gauge sits dead nuts in the middle and never moves unless something is wrong. The fan can cycle on and off but still no change on the temp gauge...just food for thought...clean and check your radiator and overflow tank, and keep an eye on the fluid levels.
Quote Originally Posted by Jiblet
Check the radiator for mud / debris, check that the fan is working properly, check the coolant level.
Sounds like lack of airflow over the radiator while you idle. These radiators are infamous for clogging up with mud, if there are signs of mud up there give it a good hosing off. Note that the radiator is behind the condenser.
Welcome to the forum!
Yup, i Agree. I will also add be sure to wash the radiator from the back side forward so you push the debris out the way it came in. And every jk I've seen with the 3.8(mine included) the temp gauge sits dead nuts in the middle and never moves unless something is wrong. The fan can cycle on and off but still no change on the temp gauge...just food for thought...clean and check your radiator and overflow tank, and keep an eye on the fluid levels.
Jiblet
Quote Originally Posted by BravoNacho View Post
Just picked up an 07 Wrangler Rubicon Unlimited. I've been drivin it around town a bit. But today I noticed that after a long freeway drive (and some stop and go in traffic) the temp gauge began to rise as I sat idle waiting for food in a drive-thru. I turned on the heater which seemed to slowed it down. Once I got back on the road it returned to its usual position at center. Any thoughts on this? Links to the right thread would be helpful. Thanks!
Check the radiator for mud / debris, check that the fan is working properly, check the coolant level.
Sounds like lack of airflow over the radiator while you idle. These radiators are infamous for clogging up with mud, if there are signs of mud up there give it a good hosing off. Note that the radiator is behind the condenser.
Welcome to the forum!
Quote Originally Posted by BravoNacho View Post
Just picked up an 07 Wrangler Rubicon Unlimited. I've been drivin it around town a bit. But today I noticed that after a long freeway drive (and some stop and go in traffic) the temp gauge began to rise as I sat idle waiting for food in a drive-thru. I turned on the heater which seemed to slowed it down. Once I got back on the road it returned to its usual position at center. Any thoughts on this? Links to the right thread would be helpful. Thanks!
Check the radiator for mud / debris, check that the fan is working properly, check the coolant level.
Sounds like lack of airflow over the radiator while you idle. These radiators are infamous for clogging up with mud, if there are signs of mud up there give it a good hosing off. Note that the radiator is behind the condenser.
Welcome to the forum!
-Tried washing off the radiator, though it looks clean already. But I may need some advice on how to do it properly. Since the fan housing is on how would i clean the radiator from the back? Should I remove it? Is it ok to spray water from inside the engine compartment through the fan?
RoysRig
Are all the little fins on the radiator still good? or have they all been smashed flat?
Are all the little fins on the radiator still good? or have they all been smashed flat?
-All the fins look okay. I wouldn't say that they are too excessively bent beyond normal (from rocks and stuff).
Ncb
Sounds like the fan might be inop since it's at normal temp while cruising but heats up when standing still.
Sounds like the fan might be inop since it's at normal temp while cruising but heats up when standing still.
TheTerminator
It's your fan not working. You can drive without a fan, especially on highway, but when you stop, there is no airflow, and that's when the fan comes in most. You can test your fan by connecting a couple jumper wires to pos+ and neg- connections on the fan. If it fires up, then it's fine. Something BEFORE the fan is at fault then. Look for a fan switch or something that controls fan activation. I'm not sure what these Jeeps have for that. Also, it could be that your coolant temperature sensor isn't working right, but you'd probably get a check engine light for that.
It's your fan not working. You can drive without a fan, especially on highway, but when you stop, there is no airflow, and that's when the fan comes in most. You can test your fan by connecting a couple jumper wires to pos+ and neg- connections on the fan. If it fires up, then it's fine. Something BEFORE the fan is at fault then. Look for a fan switch or something that controls fan activation. I'm not sure what these Jeeps have for that. Also, it could be that your coolant temperature sensor isn't working right, but you'd probably get a check engine light for that.
brian_young1
Had the same problem with my 07. Fan motor was bad.
Had the same problem with my 07. Fan motor was bad.
- Since I'm still getting used to all the sounds this Jeep makes. I think the fan is turning on but I'll check again tomorrow when I have some time. And can watch with the hood up. (at work now). I'll keep you posted. Thanks again!
JK Freak
Joined: Mar 2011
Posts: 791
Likes: 0
From: Vancouver, BC
Don't forget it can be intermittent. So even if it turns on once, doesn't mean it will turn on every time. Best is to check the fan alone. Then if you have a PID reader, drive around and keep an eye on the coolant temp. If it rises and the fan doesn't come on, you know you have a problem. I had the same problem once.