Cooling Issues

[Devil Pup]

the fins on the ac cooler are fresh and still as clean as can be, the tranny cooler is as well. so i need to check the gap in the fan shroud for sure and put a T-stat in it. and to be honest i have no clue what the timing is at

[highperf4x4]

A thermostat does not make your engine run any cooler. You can throw that out of your mind right off the bat and narrow down your stressors. The sole purpose of a thermostat is to bring your engine up to an acceptable temperature as quickly as possible to reduce carbon buildup. That's it. If you're running a gen1 engine then your motto is "cooler is better". If you want to run anything higher than a 165 then go ahead but it will not help your motor cool whatsoever. It will simply get to that temperature faster. Thermostats are cheap so you buy one of each and test it yourself. If your engine is overheating it will be the same no matter what thermostat is in it.

Likewise, a clutch fan is not going to improve your cooling much either. A flex fan is designed to flatten the blades at higher rpm's to reduce the strain on your engine and improve gas mileage. The flex fan will pull the most air at lower rpms where you need it. The same is true for a clutch fan however, when the ambient temperature is higher, a clutch fan will not "release" at higher rpms.

Your 3 core radiator should be sufficient to cool your engine provided that it isn't rediculously high on compression like 10:1. If your timing is slow or your fuel is too lean it will make your engine run slightly hotter but it's barely noticeable in stock engines.

All I can do is offer you some questions to consider.

1. Is your A/C properly charged with freeon? Your condensor will heat the air coming through your radiator and if the system is over charged then the condensor will be extremely hot. In fact, it will burn your hand if you touch it.

2. What type of heads/head gaskets are you running on your current engine? When you say the engine continues to run hot at highway speeds it leads me to suspect the heads.

3. Are you sure your water pump is not reversed for a serpentine belt system?

4. Are you sure your flex fan is not a reversed blade fan?

5. Is the crossover for coolant in your intake manifold blocked off?

6. What is your heater core setup? If you still have the factory inline valve to stop the flow of water through the heater core is it getting enough vacum to close it? You can buy a manual valve and install it in the line going from your intake to the heater core to shut off the flow of water in the summertime. Water that flows from the engine to the heater core gets dumped back into the radiator on the same side as the lower suction hose for your water pump. Therefore, it bypasses the radiator core and goes right back into the engine at nearly the same temperature as it came out. I had to install the manual vavle in mine.

7. Where is the sending unit for your temperature guage located? Is it mounted in the head or the intake? Have you let a mechanic check the temp of your engine with a digital gun while your guage says it's overheating?


You biggest ally is more water. If you can't resolve the issue you can always go to a 4 core radiator. It's a problem solver for many issues. If it were me, I'd spend the money on the 4 core before I'd invest it in electric fans. The fans will only help you if your problem is airflow and they won't be all that much better than the flex fan you have now. If you say the fins on your radiator/Condenser/Tranny cooler are in good shape and you're running the proper fan shroud then your problem is not air flow unless your fan blades are reversed.


These are just my thoughts based on experience and no disrespect is intended to anyone that's posted before me. Hopefully something I offered will help and goodluck with it.

[Stocker]

Is that a flex fan (pic in post #36 above) or a fixed-blade? I can't tell for sure...

Originally Posted by highperf4x4

Likewise, a clutch fan is not going to improve your cooling much either. A flex fan is designed to flatten the blades at higher rpm's to reduce the strain on your engine and improve gas mileage. The flex fan will pull the most air at lower rpms where you need it. The same is true for a clutch fan however, when the ambient temperature is higher, a clutch fan will not "release" at higher rpms.

Great post, but I disagree with this statement.... My truck has never run hot with a clutch fan, but consistently overheated during the brief time I ran a flex fan. And yes, it was the correct flex fan for my truck. As to a clutch fan 'releasing' at higher RPM in high ambient temps, it should -- unless the coolant temp is too high. This is based on experience with my truck and various work trucks over many years.

Originally Posted by highperf4x4

You biggest ally is more water.

Yes, and I can't recall if it's been mentioned, but a closed system with a recovery tank will help a bit, since the system will be completely full of coolant at all times.

Originally Posted by highperf4x4

As for the water wetter, it will help some but you need to make sure you flush ALL of the antifreeze out of your system first. They are not compatible. However, I would switch it back to a 50/50 mix for winter.

http://www.redlineoil.com/Products.aspx?pcid=10
* Reduces or eliminates bubbles or vapor barrier that form on hot metal surfaces to reduce coolant temperatures by up to 20°
* Superior heat transfer properties compared to glycol-based antifreeze
* Compatible with new or used antifreeze (including DEX-COOL and long-life versions) to improve the heat transfer of ethylene and propylene glycol systems
* Improves heat transfer and reduces cylinder head temperature



Was there a reply yet as to the fit (gaps) of the fan shroud?

[Sinister]

Originally Posted by Devil Pup

... and to be honest i have no clue what the timing is at

Set the timing before you start throwing money at it.