Electric auxiliary cooling fan

Flivver250

TJ Addict
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I live in an extremely hot environment. The TJ has a new radiator and is getting all new belts, hoses, high flow water pump, new fan clutch, t-stat, idler pulley and belt tensioner pulley and of course coolant as a matter of course. Is there any value in adding an additional electric fan to push air through the radiator? Keep in mind, a cool morning plummets down into the 90's here and the day can easily surpass 120°. I am thinking of adding an electric radiator fan to augment the clutch fan when moving slow either in traffic or over the sand. I assume this is well covered ground. Thoughts?
 
The advice here will be to use ALL oem parts - most importantly the radiator, water pump and fan clutch. At that point the wisdom is that it will run fine.

I don't know how many people have actually tested their jeeps in temps above 110 and I'm not sure how hard they tested it and what temps they run in those conditions. There are a few ppl here that say all oem stuff and you will be fine with whatever weather comes your way.

If you went with an aftermarket radiator, there is no saying if temps will stay within specs.

That was the long answer. Short answer is no need for an extra fan. Will it hurt? I can't imagine why, unless it blocks some airflow.

Sent from my SAMSUNG-SM-G930A using Tapatalk
 
The use of a high flow water pump could be an issue. Meaning that, it will force the coolant through the radiator too fast to reduce the temperature efficiently enough before the coolant reenters the block. I hope that made sense, it did in my low-flo mind.
 
For most applications the best advice is to stick with OEM cooling system parts. However, your ambient temperatures are even hotter than typical Arizona and Southern California summertime desert temperatures so you might need more airflow at slow speeds than the guys who frequent those areas.

I would avoid the high flow water pump and stick with OEM for the reasons stated above.

If you have an automatic transmission you would probably benefit from an auxiliary transmission cooler such as a Derale p/n 20561 or Flex-A-Lite p/n 4116TJ, both of which augment the factory cooling system without replacing or removing any factory parts.

An auxiliary fan may also help you at slow speeds by increasing airflow. This also can be done without replacing or removing any factory cooling system parts. I have a 9" 450 cfm Derale "pusher" fan in front of my external transmission cooler in my non-jeep 4x4 which is controlled by a 185 on/165 off thermostatic switch (ATF temp). It could just as easily be wired with a simple toggle switch. I have considered adding an auxiliary electric pusher fan for my LJ with automatic transmission and Flex-A-Lite external cooler, but to date I have not experienced any signs of cooling system or automatic transmission overheating so it is low on my list.
 
You may be in need of a bit more cooling. I know for hot climates jeep used to offer a 7 blade fan and heavy duty fan clutch as an upgrade for people with issues. Unfortunately those parts no longer exist for sale. On mine I did a 10 blade explorer fan with their severe duty clutch. It cured my overheating issues for a while so it seems to work better that the stock 5 blade metal fan. (this mod only fits 03+ btw) the real cure for my overheating was to get all the mud clear between the rad and ac condenser though. (probably not an issue in your area)


There must have been a time
when we could have said no.
 
What exactly is the cooling problem you are experiencing that you want to fix? Is the Jeep running too hot when stopped or in stop & go traffic, when on the highway, or does its temperature suddenly spike at times?

When in good operating condition, the OE cooling system is more up to Dubai's admittedly very hot conditions.
 
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I am not having overheating yet, I am just getting this ready for desert crawling. I am replacing the wp, hoses and t-stat as preventive maintenance, the radiator is new OEM. As it is hotter than hades I am looking to have the option for more air flow. It can get 130 in the summer, I have seen hotter in Kuwait. Maybe I am over thinking this.
 
Get your OEM cooling system into top shape and try it. Adding an auxiliary transmission cooler or an auxiliary fan are both easy jobs if it turns out that your stock system isn't up to your 130 degree summer temperatures.

If it were me I wouldn't want to find out. I stay inside when the forecast is for more than 112.
 
FWiW, the factory cooling system is more than capable of over-cooling the engine if you run a cowl intake and add hood vents. It will do this even in 100+° weather during slow crawling. I went so far as to put in a 205° thermostat to raise the temps back up to where they ought to be. Even then, my typical engine temps are often less than the hotter t-stat.

The point here is that the factory system, when it is working correctly, is very good. See what happens before you try to fix a problem that isn't there.
 
You may be in need of a bit more cooling. I know for hot climates jeep used to offer a 7 blade fan and heavy duty fan clutch as an upgrade for people with issues. Unfortunately those parts no longer exist for sale. On mine I did a 10 blade explorer fan with their severe duty clutch. It cured my overheating issues for a while so it seems to work better that the stock 5 blade metal fan. (this mod only fits 03+ btw) the real cure for my overheating was to get all the mud clear between the rad and ac condenser though. (probably not an issue in your area)


There must have been a time
when we could have said no.
The 7 blade fan and clutch were made for a specific issue with approximately a 1 year spread of TJ's that had a cooling deficiency. It was not an optional item as an upgrade, just a cure for some rigs. Something to consider is if the 7 blade fan was necessary as an overall answer to cooling issues, why was it not stock on all subsequent models? As a comparison, when the WJ was introduced, it came with Teves calipers and lots of front brake issues. When they changed over to the Akebono calipers to cure the problem, there was a TSB to retrofit all previous models with the new rotors and Akebono calipers if they had the problems, most did and you could buy the parts package in the TSB from Jeep for about 120 bucks for two rotors, two calipers, a set of pads and the new hardware.

Logic says that they solved the cooling problem a different way and eliminated the need for the heavy duty fan and clutch.
 
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The use of a high flow water pump could be an issue. Meaning that, it will force the coolant through the radiator too fast to reduce the temperature efficiently enough before the coolant reenters the block. I hope that made sense, it did in my low-flo mind.
Correctly operating, the thermostat will close and restrict flow to warm the engine up to design temps generally. You could feed the system with a fire hose and if it was robust enough to handle the pressure, the thermostat would still restrict flow to keep from overcooling the system. In other words, the high flow pump can't really force the coolant through the radiator too fast if the thermostat is doing its job.
 
FWiW, the factory cooling system is more than capable of over-cooling the engine if you run a cowl intake and add hood vents. It will do this even in 100+° weather during slow crawling. I went so far as to put in a 205° thermostat to raise the temps back up to where they ought to be. Even then, my typical engine temps are often less than the hotter t-stat.

The point here is that the factory system, when it is working correctly, is very good. See what happens before you try to fix a problem that isn't there.
Where are you reading your engine temps?
 
What does the dash gauge say?
Pointed straight up. When I was experiencing the over cooling, it was favoring to the left. OBDII readings would drop into the 180s.
 
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The 7 blade fan and clutch were made for a specific issue with approximately a 1 year spread of TJ's that had a cooling deficiency. It was not an optional item as an upgrade, just a cure for some rigs. Something to consider is if the 7 blade fan was necessary as an overall answer to cooling issues, why was it not stock on all subsequent models? As a comparison, when the WJ was introduced, it came with Teves calipers and lots of front brake issues. When they changed over to the Akebono calipers to cure the problem, there was a TSB to retrofit all previous models with the new rotors and Akebono calipers if they had the problems, most did and you could buy the parts package in the TSB from Jeep for about 120 bucks for two rotors, two calipers, a set of pads and the new hardware.

Logic says that they solved the cooling problem a different way and eliminated the need for the heavy duty fan and clutch.
Interesting, I was under the impression that the 7 blade fan was a tsb item that they retrofitted for jeeps in hot climates when they had overheating issues. Didn't realize it was limited to one production year. Good to know, thanks.


There must have been a time
when we could have said no.
 
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Interesting, I was under the impression that the 7 blade fan was a tsb item that they retrofitted for jeeps in hot climates when they had overheating issues. Didn't realize it was limited to one production year. Good to know, thanks.


There must have been a time
when we could have said no.
Copy of the TSB wording- Note the various solutions depending on which calibration level exists in the PCM. It wasn't quite as simple as "toss this on and fix the problem" which is what the internet has bastardized the existence of the fan and clutch into, while failing to recognize if it was actually needed, it would be on all rigs that go to the UAE and other hot areas, and be optional for some places in the US. It doesn't exist because it isn't needed.

Also of importance is the conditions under which the overheat condition occurred.


2001 Jeep Truck Wrangler L6-242 4.0L VIN S SFI

Temperature/Check Gauges Light ON

Engine - High Temperature/Check Gauges Light ON

NUMBER: 07-004-01 REV A

DATE: Dec. 14, 2001

THIS BULLETIN SUPERCEDES TECHNICAL SERVICE BULLETIN 07-004-01, DATED JULY 20, 2001.

SUBJECT:

High Engine Temperatures Due To Extended In-Gear Idling In Hot Ambient Temperatures

OVERVIEW:

This bulletin involves replacement of the cooling fan and fan drive. Certain 2000 M.Y. Wranglers will also require selectively erasing and reprogramming the Powertrain Control Module (PCM) with new software (2000 TJ - Calibration Level Cal15A).

MODELS:

2000 - 2001 (TJ) Wrangler

NOTE : THIS BULLETIN APPLIES TO WRANGLERS EQUIPPED WITH A 4.0L (ERH)

ENGINE AND A 32RH AUTOMATIC TRANSMISSION (DGG).

SYMPTOM/CONDITION:

Engine coolant temperatures may rise high enough to cause the Check Gauges light to illuminate, indicating high engine coolant temperature. This condition is likely to happen after extended periods of idling, with the transmission in Drive, the air conditioning on, and with ambient temperatures greater than 35°C. (95°F.). If the transmission is placed in the Park or Neutral positions, or if the vehicle is driven, then the engine temperatures will decrease.

DIAGNOSIS PROCEDURES:

NOTE : REFER THE CUSTOMER TO THE RESPECTIVE 2000 OR 2001 JEEP

WRANGLER OWNER'S MANUAL AND TO THE SECTION TITLED: WHAT TO DO IN

EMERGENCIES - IF YOUR ENGINE OVERHEATS. IT IS IMPORTANT THAT THE

PROPER PROCEDURES ARE FOLLOWED TO PREVENT AN ENGINE OVERHEAT

CONDITION.

NOTE :INFORM THE CUSTOMER THAT THE REVISED FAN AND FAN DRIVE WILL

CREATE HIGHER SOUND LEVELS FOR A MINUTE OR SO AFTER A COLD ENGINE

START, AND DURING HIGH ENGINE TEMPERATURE CONDITIONS.

**THE FAN WILL RUN MORE OFTEN BECAUSE THE FAN CLUTCH WILL NOW ENGAGE AT LOWER TEMPERATURES.**

PARTS REQUIRED:

EQUIPMENT REQUIRED:

NOTE :THE MDS2 AND DRB III(R) ARE REQUIRED TO PERFORM PART OF THIS

REPAIR. WHEN USING THE MDS2 AND THE DRB III(R), THE SYSTEM MUST BE

OPERATING AT CIS CD 2064 OR HIGHER.

REPAIR PROCEDURE:

1. Verify that the cooling system is in good working condition.

2. Verify that the engine coolant mixture contains the proper amount of antifreeze.

3. If the customer complains of the above condition, and the vehicle is a 2000 Wrangler

with PCM software that is earlier (lower or less) than the calibration listed above, perform the complete Repair Procedure.

4. If the customer complains of the above condition, and the vehicle is either a 2001 Wrangler or it is a 2000 Wrangler with PCM software already at calibration level 15A or later, then perform only Step 1 of the Repair Procedure (replace only the fan and fan drive).

Verify the current PCM software calibration level (2000 Wrangler only). If the 2000 Wrangler PCM software calibration level is earlier (less or lower) than 2000 TJ - Calibration Level 15A, then proceed with steps 2 though 4.

NOTE :THE FOLLOWING STEPS ARE REQUIRED BY LAW.

1. Replace the cooling fan and viscous fan drive. Refer to the appropriate Wrangler Service Manual, Section 7 - Cooling Engine, for detailed fan and fan drive removal and installation instructions. The Service Manual procedures may be found on the MDS2.

2. Reprogram the PCM using the MDS2 (Mopar Diagnostic System) and DRBIII(R) (Scan Tool).

3. Type the necessary information on the "Authorized Software Update Label" p/n04669020. Attach the label to the PCM and cover the label with the clear plastic overlay.

4. Type the necessary information on the "Authorized Modification Label" p/n 04275086 and attach the label near the VECI label.
 
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Interesting, I wonder what it is about the 2000/2001 jeeps that caused the need for it.


There must have been a time
when we could have said no.
 
Interesting, I wonder what it is about the 2000/2001 jeeps that caused the need for it.


There must have been a time
when we could have said no.
A question I've pondered many times and since we get to deal with all the models, there is no immediately obvious difference in components except for two that are obvious. First is they updated the radiator from a 2 row to a single larger row which then became the standard even for earlier models and stayed the same through 2006. The other is the switch to a different water pump and changes to the engine block to accept it which happened in 2000. The new pump has a plastic impeller and is very reliable and much more so over the older metal impeller style.

None of that is mentioned in the TSB so that shouldn't have much effect.