vr4stealth

Hey guys so I have a 92 es300 and the car over heats while at idle but not while driving.
This car only has one fan? I was gonna check if the fan was turning on but the ac was on at the time and it was on. thought there was gonna be another one as well.
So what can I do to check what it can be? Ive already bleed the system for air

IzzyB

I would say stuck thermostat, not really sure though. It makes sense though, hot when not moving (ie. no air movement to cool) cool when moving (ie. air IS cooling). Also the fan like you said, but you also said AC was on, that can affect cooling too since the extra load.

Either way, I'd check the thermostat if you haven't done that, or it hasn't been replaced.

Hayk

iTrader: (1)

Air flow issue is possible. Not sure about 92, especially with those hydraulic fans, hopefully somebody can chime in with experience.

Do you have any oil leaks, particularly in power steering? It controls the cooling fan.

vr4stealth

thanks I will check the thermostat and see if any leaks

CUMan

We had a similar problem with our 94 ES several years ago. After a lot of trying to figure out what was causing the problem, we narrowed it down to the hydraulic fan.

The fan is supposed to speed up when the engine coolant temperature rises. At highway speeds, there is enough air flow across the radiator that the fan speed is not important. When moving slowly or when idling without moving, the fan speed is supposed to speed up to give more air flow. The fan speed is controlled by a control module underneath the glove compartment inside the car. This module has a connector which runs through the firewall and attaches to the power steering pump. When the control module senses that more fan speed is needed, it sends a signal to the power steering pump. The pump responds by increasing the power steering fluid flow, which raises the fan speed.

In our car, this connector had been damaged, thereby cancelling the signal from the control module. There have also been a number of postings on this forum about the connector not being plugged into the power steering pump. My suspicion has always been that a lot of auto repair folks do not understand the importance of this connector since the Lexus-Toyota hydraulic cooling fan is quite unique. If repairs are being made to the power steering pump or hoses, this connector may get removed and then not reconnected when the work is done. The cooling fan will still turn, but it won't speed up when more fan speed is called for.

Check to make sure this connector is plugged in properly.

lluahs

I had this issue for a year and a half before I figured it out. Pretty much what the above post is stating. If you jump terminals e1 to op1 the radiator fan should turn on full blast, if not then you probably have a loose or unconnected sensor wire(grey and under the passenger wheel well by power steering pump). Hope that helps.

https://www.clublexus.com/forums/es3...ling-over.html

vr4stealth

Thanks for the reply's will check those things out