so i have done the Efan swap/mod?upgrade... its not as simple as everyone thinks or makes it out to be. i went with flexilite and here is my "story"...
background; i had an issue with my AC a couple years ago and my expansion valve froze or broke. so i didnt have AC for the longest time. well this last summer i decided to fix that, so bought a new dryer, expansion valve and scored a low mileage evaporator. put it all in and vac'd the system and filled it. boom had AC again, but now i presented my self with a new problem... overheating. even at hwy speeds i would run warmer than normal -granted it was high 90-100* days, and in traffic it was too much, id peg the needle if i wasnt careful. i bought a scangauge just to make sure it wasnt a bad sending unit for the dash gauge. and no 220* hwy 210* if it was open air and i could do 70+. and in city or stop and go traffic 240*+. infact id have to shut down the AC and turn on the heat. -i also have dual trans coolers in front of the AC condenser, and 2 big IPF lights as well as my winch control box up front on my bumper in front of the grille, not to mention my ~5400lb daily average curb weight with the larger tires(but i have 4.88 gears)
i had a 2 year old rad, and less than a year on the WP, TB and T-stat. i flushed the coolant but that didnt help. so i figured at 300k the stock clutch fan was giving up the ghost. so i bought a flexilite kit and installed it. i still was having issues, i couldnt keep it cool on the hot days. at night i was ok but anything over 80* ambient temps and i was in trouble. so i bought a 170* thermostat, it helped but was still not the answer. i would still overheat if idling with the AC on.
FYI the flexilite kit that has the adjustable thermostat regulator for the fans is ok, but the wiring they provide with it is crap, not to mention they cant wire corectly. -i ran power to the red wires, and ground to the black wires coming off the fan motors themselves. then come to find out they wired the fans wrong(sorta) one fan was wired backwards so it was pushing air while the other was pulling WTF not to mention its to small gauge wire to handle the load of the fans idk wtf the engineers were thinking at flexilite. so i ripped out all the wiring that came with the kit and redid the wiring myself. this time using 10awg for the main power from the battery to the control box/adjustable thermostat, and from there to the fans themselfs, same with the grounds. then i used 14awg for everything else. i also used much larger awg fuse pocket leads -12awg as it was the biggest i could find. (i fused the power to the adjustable Tstat/regulator from the battery, as well as from the regulator to the fans so i am double fused for protection of any shorting that could happen) i had issues with the fuses getting too hot and actually physically melting down. they would not pop, but the wire wasnt able to handle the load the fans demanded and would literally melt the wires and the rubber fuse pocket as well as the plastic surrounding the fuse element. the fuse however would not pop typically, but the element would fall out of the fuse because the plastic would melt and no longer support it. ok so i got that fixed and wired correctly. but not before having several instances of power loss to the fans and the truck severally overheating ie once saw 276* according to the scangauge -and having coolant boil out of the overflow and all over the ground. -no head gasket failure though and no other damage.
now my issue was i had no place for all that heat to go. so it would build up under the hood and then my air intake temps would just spike and id get predet in the cylinders and eventually id overheat given enough time. so i set out to try two last things before i said F it and would buy a new clutchfan from the dealer and use it. the first was the TRD 160* thermostat used for the TRD supercharged trucks and runners. at $70 its not cheap but i knew that when i went from the stock Tstat to the 170* i saw good improvements and i would probably see more if i went lower still. the other thing i did was order a set of RunCool hood louvers (medium hiflow) for the hood to give all that heat a place to go/escape. now i did both of these mods almost together, Tstat first and a couple of days later. the 160 Tstat did a major improvement and i was not longer overheating at idle or in traffic with the AC on full blast, but i also was not pulling a trailer or pulling any grades so i wanted the extra insurance of the louvers so i installed them -basically templated them on the hood, found the best asymmetrical location for them that would allow for the (IMO) maximum value or gain for ventilation of head, and then cut them out per the instructions. installed the hood louvers and have never looked back. i have no more issues with predet, and a big added benefactor is my intake temps are much much cooler than they used to be, and not nearly as affected by the coolant temps as they used to be.
i have had several days sense then of hot weather as well as multiple heavy loads towed (fullsize f150 long bed extra cab 4x4) up a long steep hill and the temps never got over 220* with the AC full blast. typically im around 190-196*. at night or on the hwy im a little lower ambient air temps have a great impact on this. and city driving im right around 200-204* -note that at 220* the gauge on the dash is no different than ~185* so the stock dash gauge on our 4runners is very liberal in its range. i think it has a "safe operating range" and anything in that it sits at on the gauge like there is no fluctuation, when in reality there is a good amount.
overall i am happy i did this mod, but it was not without its trials and headaches and ulcer creating moments. i would say this is not a simple mod by any means, but rather a complex mod that requires a lot of work and other secondary and tertiary mods to make work. i feel i have this figured out quite well and would have no reservations about doing this mod again, but i would not try to leave out anything i have done. i feel its too risky to not do ALL of this to make it work and be reliable. -the only thing id change and still might is my fuse awg wiring, id like to go to 10awg like everything else and will as soon as i can find some.
