OK, I have been having the nightmare of all overheating problems. Car is fine at idle, driving, and stop and go traffic w/ the A/C OFF. Once the A/C goes ON, the car overheats. The fan DOES spin but we can stick our hand in there and stop it regardless of the conditions.

Replaced:
Water pump, radiator, radiator hoses, thermostat, overflow tank, overflow sensor, fan assembly.

Not replaced:
Fan pump, solenoid, AC Pressure Switch, Coolant Temp Sensor, A/C ECU, Cooling path for ATF Oil

We pulled the solenoid out of the car, we put 12V to it, and nothing happened. We used a grinder to take off the little thing inside hoping it would just push oil through at 100%, nothing happened.

Fan pump not working a possibility? Who has replaced it? $300 item from lexus and does not look like a fun job.

 

I highly doubt that pump would die - it's built the same way an oil pump is and they are extremely reliable - they almost NEVER wear out, I honestly don't know if I've ever seen one worn so much they wouldn't work (they usually leak first)...

anyways, go to this link: https://www.clublexus.com/forums/sho...d.php?t=288108

and do that - it's a mod too

 

i don't want to do the electric fans, the stock fan is supposed to be more powerful.

what else could it be then if not the pump?

 

I would need to look at the schematics for it - tomorrow I should have a chance to...

 

i pulled the hoses off the fan assembly to see how the fluid movement was, it was steady stream but not super powerful, so i think that eliminates any possible blockage in the cooling system.

the only thing left is the pump and solenoid because regardless of the other sensors (a/c pressure sensor, coolant temp sensor, a/c ecu), the fan should default into fail safe if anything is wrong, or so the service manual makes it seem.

 

um, I just checked mine, and it moves pretty slow too... slow enough to stop with my hand... my car doesn't get hot at all (and it's been 105-110 here for the past two weeks)... maybe you are chasing the wrong problem...

 

hm, this is just puzzling, the car does not overheat at all, and it's been 80s/90s here, it only overheats when the A/C is on.

i'm going to try the solenoid and the coolant temperature sensor (not sure why this would be the reason since the car does not overheat at all while the a/c is off)

 

so now the A/C does not blow cold at all. when it did, it overheated. brought it to a shop, they said all they see is some condensation on the evaporator. keep in mind the system was recharged less than 2 months ago. now i'm totally lost, car is just a huge mystery.