Radiator fan

[hear]

Simpler: I'm seeing more radiator/cooling system issue threads on TJ online forums and several TJ groups I follow on FB.

The TJ's being discussed are older than they've ever been as well, and get older every year. What's more likely the culprit, that the average climate has increased by single digit degrees (and therefore the delta between engine operating temp and ambient temp has changed from ~110F to ~108F), or that a system that is 25 years old and likely poorly maintained over that time is reaching a point of age/disrepair where it no longer functions as it did from the factory?

Could the cooling system be improved upon? Certainly. Find a more efficient way to transfer heat out of the engine. Seems like the aftermarket hasn't been able to do it yet, or at least not reliably. But let's not blame global warming when its obviously much more likely that your shit is just old.

 

[B1Toad]

Hi! I’m rebuilding a 2000 jeep TJ, I have replaced the radiator but I’m looking for a fan that has for blades because the engine runs hot. Is there any recommendations for a new replacement fan with more blades? That anyone would recommend and mind sharing with me!

Thank you.

Is it overheating at idle or at speed? AC on or off? Have you verified that the fan clutch is working? Is the shroud intact and installed tight to the radiator? Do you happen to have grill inserts? Which radiator did you buy?

 

[machoheadgames]

Irrelevant to the thread subject but relative to your statement (paraphrasing) Stock setup is best/far too often, aftermarket is significantly worse.

1: Aftermarket, as often, can be significantly better than OEM — modern technology/design vs. 3+ decades ago.

2. "Regardless of what the mean temp is and whether or not it’s higher than it used to be...":

Endurance Warranty’s analysis* (July 24, 2025) notes that as extreme heat becomes more common, traditional vehicle systems—including cooling systems—are seeing increased repair frequency and earlier failure. Even simpler: I'm seeing more radiator/cooling system failure threads in the forum as well as several on FB I follow.

* "How Climate Change is Influencing Car Repair Trends" - https://www.endurancewarranty.com/l...mate-change-is-influencing-car-repair-trends/

"Climate change is making car repairs more frequent and expensive. Extreme heat, freezing cold, flooding, and poor air quality are putting new stress on vehicle systems, from batteries and electronics to cooling and suspension. These conditions are causing parts to fail sooner and increasing the likelihood of costly breakdowns."

Simpler: I'm seeing more radiator/cooling system issue threads on TJ online forums and several TJ groups I follow on FB.

Summary: stock is not always better.

You’re seeing increasing posts because the vehicles are gaining age. 20-30 year old radiators don’t work very well, neither do water pumps, thermostats, and fan clutches. Irrelevant and despite the global warming argument, vehicles today are not suffering because of any higher temp than in past years. Mean temp is useless anyways because it muddies the waters about what the cooling system has to actually deal with by taking an average of the whole country over a long period like a full year. A increase of 3° in 30 years tells you absolutely nothing. Look at the high end if you want to see anything relevant, because those are the days that matter.

Let’s take Dallas for example since it gets decently warm here.

Hottest temp on record:

Tie for 1st place: June 26-27 1980 - 113°F

Tie for 7th place: 110°F

September 8 2023
August 26 2023
August 25 2023
August 2 2011
July 12 1998

So what did they do to make CJs handle 113° 45 years ago? What did they do to make the TJ handle the same temp in 1998 as we saw in 2023 for 3 days? This argument is bunk.

And if none of that is enough, all the Jeeps I’ve driven here have done absolutely perfectly fine with an OEM cooling system provided the parts are in good shape. The problem is not the old design. The problem is bad parts or old worn out parts. Or contributing failures like cracked heads or head gaskets. It is not that we have global warmed ourselves out of our 30 year old cooling system designs.

 

[KennethS]

Agreed. Look at average Phoenix summer temperatures over the past 30 - 40 years. No one had overheating issues during that time when the vehicles were new.

 

[DuckNut]

Agreed. Look at average Phoenix summer temperatures over the past 30 - 40 years. No one had overheating issues during that time when the vehicles were new.

I'm sure they did...but didn't have the Internet to spread their complaint on 6 different forums at the speed of light.

 

[DuckNut]

Irrelevant to the thread subject but relative to your statement (paraphrasing) Stock setup is best/far too often, aftermarket is significantly worse.

1: Aftermarket, as often, can be significantly better than OEM — modern technology/design vs. 3+ decades ago.

2. "Regardless of what the mean temp is and whether or not it’s higher than it used to be...":

Endurance Warranty’s analysis* (July 24, 2025) notes that as extreme heat becomes more common, traditional vehicle systems—including cooling systems—are seeing increased repair frequency and earlier failure. Even simpler: I'm seeing more radiator/cooling system failure threads in the forum as well as several on FB I follow.

* "How Climate Change is Influencing Car Repair Trends" - https://www.endurancewarranty.com/l...mate-change-is-influencing-car-repair-trends/

"Climate change is making car repairs more frequent and expensive. Extreme heat, freezing cold, flooding, and poor air quality are putting new stress on vehicle systems, from batteries and electronics to cooling and suspension. These conditions are causing parts to fail sooner and increasing the likelihood of costly breakdowns."

Simpler: I'm seeing more radiator/cooling system issue threads on TJ online forums and several TJ groups I follow on FB.

Summary: stock is not always better.

That's funny chit right there. Using climate change to explain away aging parts or poor maintenance is precious.

 

[Harold&Cat]

I recently installed a new Koyorad radiator , Robert Shaw thermostat , USMW fan clutch and did an engine flush . The engine runs normal temperatures driving or idling for extended periods of time with the air conditioner on in 100 degree weather . I am running the original stock five blade fan .

If your Jeep is overheating , there is a problem somewhere in the system .

 

[jeepguy03]

I recommend rebuilding the cooling system with good aftermarket or OEM parts, flushing it out and then going from there.
-radiator (OEM if you can find it, Denso, Spectre)
-hoses (gates or Ac Delco, or OEM Mopar)
-thermostat (195*, I have a Stant Superstat in mine)
-radiator cap (I have a Stant cap as well)
-water pump (Mopar, Ac Delco, Gates)
-fan clutch (hayden, USMW)

Also make sure your AC condenser in front of the radiator is clean, my TJ hasn't overheated but the condenser was completely packed full of dead bugs when I got the Jeep. Overheating at low speeds is usually an airflow problem, pointing to a radiator issue or failing fan clutch. When you shut the Jeep off at full operating temperature the fan clutch should have resistance to turning it by hand. It will spin, but not as freely as on a stone cold engine. I've had several fan clutches of all brands (even Mopar) be bad right out of the box causing low speed hot coolant temps.

 

[KennethS]

I'm sure they did...but didn't have the Internet to spread their complaint on 6 different forums at the speed of light.

True. I worked at a couple auto parts stores and a full-service gas station, plus all the car guys I hung out with all drove 60s-70s cars that were 15+ years old at the time, so I may have been more in tune with car related things than the average person.

 

[KennethS]

That's funny chit right there. Using climate change to explain away aging parts or poor maintenance is precious.

How opportune that this was on the afternoon weather today. Phoenix summer high temperatures have increased by a whopping 4 degrees over the past 100 years. That amount of “global warming” isn’t gonna result in a dramatic increase in vehicle systems failures.

 

[KennethS]

What's more likely the culprit, that the average climate has increased by single digit degrees (and therefore the delta between engine operating temp and ambient temp has changed from ~110F to ~108F), or that a system that is 25 years old and likely poorly maintained over that time is reaching a point of age/disrepair where it no longer functions as it did from the factory?

As said, single digit temperature increases. The data above corroborates that statement.

 

[DuckNut]

How opportune that this was on the afternoon weather today. Phoenix summer high temperatures have increased by a whopping 4 degrees over the past 100 years. That amount of “global warming” isn’t gonna result in a dramatic increase in vehicle systems failures.


View attachment 634227

100 million years ago the planet was just a big ball of molten lava. We are a long way from where we came from.

 

[KennethS]

100 million years ago the planet was just a big ball of molten lava. We are a long way from where we came from.

Next you’ll be telling us the present day sea levels are different than they used to be.

 

[GoldenGorilla]

Next you’ll be telling us the present day sea levels are different than they used to be.

Denver was a pretty sweet beach town back in the day.

 

[DuckNut]

Next you’ll be telling us the present day sea levels are different than they used to be.

Got a full stomach eh?

 

[Harold&Cat]

According to Scripture , our planet is approximately 6000 years old . Of that 6000 years , we have about 200 years of records . I would say the "averages" are flawed .

 

[JMT]

The OP should try the “Climate BS” thread.

 

[Apparition]

The OP should try the “Climate BS” thread.

I thought this was it yesterday then realized it wasn’t and deleted my post.