I have a rebuild 22re that keeps overheating. The only time it starts to overheat is when I m moving real slow " 4 low slow" or the truck is under some type of a load. It has new a radiator, tstat, and a electric fan no fan clutch. It will stay cool most of the time as long as I am moving. I can drive around with out even using the electric fan. I have looked into the dual stage tstat but wanted to see what people thought. Thank you.

 

Insufficient air flow due to removing the stock fan and radiator shroud, and/or the e-fan not moving enough air. Possibly, fan control on temperature set-point too high as well, or the sensor location is not in a good place.

 

Another thought; you need to bump up to the V6 radiator. Fans are for below 30mph. You have air flow and surface area issues.

Look to see if the radiator fins are too dense, or fan shrouds stink for flow.

Honest; on a slow rig its hard to beat the factory fan & shroud. Electrics work great on some applications, on our toy trucks they just do not seem to cut the mustard.

One trick from the race car; prop up the back of the hood so hot air can escape in front of the windshield.

Now for a really trick look; have the hood louvered just like the hotrods of old!

 

The guy I bought the truck from put a V6 radiator in it. I haven't got it hot enough to see if the Tstat is not opening, it starts to get close to the red and I panic. I have heard people saying about "over shooting".

 

+1 on shroud/airflow. AND sticking to stock fan clutch.
Did you have the the problem before you "fixed" things?
Electric fan is good for performance, stock fan clutch for reliability. How many miles on the fan clutch before it needed replacement? Would you be happy with that many more miles until next replacement?

 

My e-fan controller got stuck on once... it melted the fuse. I put the stock fan back in without the shroud (because I was lazy), and it was just fine (AC and everything)

With my 3.4 swap, I'm going with the stock fan. I'll add a shroud later, but it should work fine (no AC for now)

tl:dr- unless you're racing, put the stock fan back on

 

Not to hijack the thread but has anyone tried the Flex-fan from LCE's website? It looks like it takes the clutch out of play and the fins flex depending on RPM so the blades are cupped when at low RPM and flat or less cupped at high RPM. Only side effect is increased noise. Positives for the fan is increased Flow and less blade drag at high RPM. Let me know. Thanks

 

Visit Hotrod.com / youtube ; they did a test on these fans. Stock wins at low power & rpm. the test results will change your mind on this subject.

 

Overshoot happens on 4runners with the cold air kit option and its in use.

Drill two 1/8 in holes in a blank area of your t-stat to help it open. Now I suggest you test it. get a junk pot, not one used for food, and boil your t-stat in it to see if it even opens up. I have a box of bad / junk T-stats that look like new but do not open or open too late. Pick a name brand they have new junk for $$$$$ . Once you find a good one, it lasts a long time, do not lose track of it.

 

So I just got done messing around with my truck. It will not over heat at idol and the electric fan on. I noticed when I had the radiator cap off while it was running it didn't seem like coolant was moving inside it just kept coming out the top unless I idled up. The temp gauge was at half.