Running Hot

[Rooster73]

Hey guys, I’m new here, I’ve been banging my head against the wall on an overheating issue. I have an 06 LJ that I have had for several years, never had an issue with it running hot until we came to Cali (we are from the Midwest) as soon as we got out here I noticed it was running hotter than I’d like, not excessive at first but this spring it blew the bottom tank off of the factory radiator, I replaced it with an aluminum 4core radiator from summit with a Flexalite Flexwave electric fan and a 180 degree thermostat It is still running hot . My water pump is only a couple of years old, and I don’t have a blown head gasket. Any ideas?

 

[KennethS]

Is it hot at speed (while driving) or while idling / driving slowly?

Did you keep the mechanical fan, or remove it when you installed the electric fan? I ask because many aftermarket electric fans just do not move as much air as the factory mechanical fan.

 

[CharlesHS]

The area you moved in to in California; is the location at a higher elevation than where you lived previously ?
Increased elevation and warmer temperatures can cause that to happen when the engine needs to worker harder.
When you replaced the radiator; did you perform a flush on the system ?
I agree with the response above; what is the documented air flow (CFM) of the installed electric fan ?
The factory clutch&fan along with factory radiator work very well together.

 

[pbeach]

The area you moved in to in California; is the location at a higher elevation than where you lived previously ?
Increased elevation and warmer temperatures can cause that to happen when the engine needs to worker harder.
When you replaced the radiator; did you perform a flush on the system ?
I agree with the response above; what is the documented air flow (CFM) of the installed electric fan ?
The factory clutch&fan along with factory radiator work very well together.

(different vehicle - '06 TJ v '06 LJ + Rooster73 didn't identify his engine) ... but FWIW: 8 months ago, I upgraded the 18-year-old stock fan (which spent it's life in the tropical heat of South Florida) because I was moving to the high desert of New Mexico. From sea level to 5300'. Call it preventative maintenance.

The stock electric fan on my 2.4L engine is rated at 1,250 to 1,400 +- CFM — upgraded to a SPAL 16" puller (SPU-IX-30102113 | https://www.summitracing.com/parts/spu-ix-30102113#overview — rated: 2,500-2,599 CFM.

Radical difference. Standing in front of the grill with a loose shirt, you can feel it pulling the shirt. Crazy.

 

[CharlesHS]

'06 LJ + Rooster73 didn't identify his engine) ...

In Rooster 73s profile he stated the engine is a 4.0L.

 

[hear]

Hey guys, I’m new here, I’ve been banging my head against the wall on an overheating issue. I have an 06 LJ that I have had for several years, never had an issue with it running hot until we came to Cali (we are from the Midwest) as soon as we got out here I noticed it was running hotter than I’d like, not excessive at first but this spring it blew the bottom tank off of the factory radiator, I replaced it with an aluminum 4core radiator from summit with a Flexalite Flexwave electric fan and a 180 degree thermostat It is still running hot . My water pump is only a couple of years old, and I don’t have a blown head gasket. Any ideas?

In addition to what's been stated already, you want a 195* t-stat. Running a 180* isn't going to make your engine run at 180. As far as aftermarket radiators go, just search here. By and large, the OEM radiator does the best job. Others have had success with the Denso, anectodally other brands have probably worked as well.

In general, if you've never done so I would recommend a chemical flush (or 3 or 4) while you're changing that t-stat out and putting the OEM fan & clutch back in. And then re-evaluate. You will be hard pressed to find much evidence here for improving the cooling with aftermarket parts. Not that it can't be done, just that nobody has really seemed to find parts that reliably do it. Hundreds of threads on the topic.

(different vehicle - '06 TJ v '06 LJ + Rooster73 didn't identify his engine)

The LJ only came with the 6cyl, fyi.

 

[Rooster73]

In addition to what's been stated already, you want a 195* t-stat. Running a 180* isn't going to make your engine run at 180. As far as aftermarket radiators go, just search here. By and large, the OEM radiator does the best job. Others have had success with the Denso, anectodally other brands have probably worked as well.

In general, if you've never done so I would recommend a chemical flush (or 3 or 4) while you're changing that t-stat out and putting the OEM fan & clutch back in. And then re-evaluate. You will be hard pressed to find much evidence here for improving the cooling with aftermarket parts. Not that it can't be done, just that nobody has really seemed to find parts that reliably do it. Hundreds of threads on the topic.




The LJ only came with the 6cyl, fyi.

I have flushed it, the factory thermostat was actually a 210 degree thermostat, the factory radiator was a single core plastic tank piece of junk that failed, and you can not run the factory fan and clutch with a 4 core radiator because there is not enough room.

 

[KennethS]

I have flushed it, the factory thermostat was actually a 210 degree thermostat, the factory radiator was a single core plastic tank piece of junk that failed, and you can not run the factory fan and clutch with a 4 core radiator because there is not enough room.

My factory single core plastic tank piece of junk radiator lasted over 15 years before the top tank split. I replaced it with a parts-store factory equivalent single core plastic tank piece of junk 6 or 7 years ago and it's been cooling the engine fine in our 110+ summer temperatures, in rush hour traffic, with the AC on.

So it can be done with the right parts.

 

[machoheadgames]

I have flushed it, the factory thermostat was actually a 210 degree thermostat, the factory radiator was a single core plastic tank piece of junk that failed, and you can not run the factory fan and clutch with a 4 core radiator because there is not enough room.

You’ve had your LJ for several years, technically unless you verified the Mopar tag, you don’t know that your factory radiator was even still in the Jeep when you got it. The factory ‘junk’ has a pretty decent reputation and doesn’t have problems cooling an engine in Cali, so…if it truly was factory, then that’s 19ish years of good service. Also, the factory thermostat is a 195°. 205° is an aftermarket option.

You say temps are higher than you like….what are the actual temps?

Multi row radiators are not known for better cooling. I think people think they are better for cooling and so the market took off running with them, but rows alone do not make better cooling. You’d be better off buying a Spectra or Denso standard radiator and going back to the factory mechanical fan. If the thickness of the 4 row was why you had to ditch the mechanical fan, I’d have never installed it from the get-go. It has been documented on forums for 25 years that aftermarket electric fans work poorly, in general, in locations that get hot. Mechanical fan is much better.

 

[hear]

I have flushed it, the factory thermostat was actually a 210 degree thermostat, the factory radiator was a single core plastic tank piece of junk that failed, and you can not run the factory fan and clutch with a 4 core radiator because there is not enough room.

Sounds like you have all the answers.