Trahald

Hi guys, I have 1996 ES300 and my engine temperature goes up when I leave AC open for 30 minutes. When I close the AC it turns normal in couple minutes. I live in California and weather is really hot in those days like 90.

So, I have changed my radiator(brand new), upper hose and lower hose 2 months ago. Coolant level is good. Oil change has done 1 month ago. What could it be the problem?

hypervish

Do the fans turn on?

mitmaks

You leave your AC open? You mean you turned it on? Check to see if your fan is working.

DplanDman8

I had almost the same problem. When I would come to a stop and sit there or had my AC on while driving she would get warmer then usual when I looked at it I noticed like ^^^ they said my fans where not turning on. One of the clips to the fans had broken off im assuming because the plastic got old and dry and came of i just replaced it and the problem had gone away.

Look at your fans!!

Trahald

Yes I mean I turn it on. When I start the car fan is working. I am going to check the plugs though but where should I look specifically for plugs?

mitmaks

I'd check thermostat and radiator, good idea to flush out radiator/heater core. Also check your A/C condenser, if it's obstructed or dirty then it will reduce air flow and cause overheating.

Yurka

check thermostat i had same on my 2000ES, replaced thermostat and it was all good!

Hayk

iTrader: (1)

Doesn't sound like a thermostat issue. There are two fans on these vehicles. One is used for primary engine cooling, and the second one is there to provide additional cooling during A/C operation. The A/C Fan should come on as soon as you press the switch. The primary fan that's independent of the A/C will cycle On and Off depending on the temperature of the coolant.

Cliffs: Open the hood and see if you can control the A/C fan.

LeX2K

Once again the cooling fan on these cars is misunderstood. The fan is not electric but hydraulic, it depends on the power steering system working properly. There is a hydraulic/electric solenoid on the power steering pump itself, this is controlled by a small ECU on the right hand side kick panel.

Most often the problem is a leaking PS system, a broken or disconnected wire on the power steering pump, or a clogged filter (bolted to the radiator) due to lack of maintenance.

Hayk

iTrader: (1)

Thank you, I keep forgetting that the 2ES is old school.

LeX2K

I thought for the longest time that the 1994 and up ES had electric fans because it has the 1MZ engine. But nope, they still used the most over engineered cooling fan of all time. It is a very quiet fan, and is infinitely variable which is neat. But certainly not worth the complexity.

CUMan

A very common problem with the ES models having the hydraulic cooling fan system involves the wiring between the cooling fan ECU (mentioned above) and the power steering pump not being properly connected. This wiring comes through the firewall and plugs into a receptacle on the PS pump. It appears that this connector is often left disconnected when repairs or maintenance work is being done involving the engine components around the PS pump. This type cooling fan system is unique (and certainly over-engineered), and a repair person may not realize how important this connection is for proper cooling fan operation.

The cooling fan ECU controls the fan speed. When more cooling is needed, a signal is sent to the PS pump calling for higher hydraulic flow to the cooling fan. This speeds up the fan, thereby providing more cooling. Such additional cooling is needed especially when the car is idling or moving slowly. When moving at higher speeds, the air flow across the radiator is often adequate to provide proper cooling.

I would check to make certain this connector is properly installed. You probably cannot see it from the top of the engine. It might be necessary to remove the right front tire and then remove the panel from the wheel well to see into this area good enough to check out the connection.

Trahald

Thank you for all infos guys. When I have a chance I am going to check the wires and connections that you mentioned.

Ichigo1287

My 96 es300 is doing the same thing but it does it with or with out the ac going I am at a complete lose on it the entire cooling system has been replace expect the fan and its control systems. I will give all this stuff a look over. Is there something more i need to look at. The fan does spin but it seems slower than it should be going please help

CUMan

There is a rather simple test to see if the cooling fan is operating properly.

On the passenger side of the engine compartment is a small diagnostic port. It is a black box about 1" X 3". It is just to the right of the passenger side strut. The top of this box opens up. Inside you will see several terminals. If you connect a jumper between terminals E1 and OP1 (with the engine running), the cooling fan should speed up. If it doesn't speed up, there is a problem somewhere in the cooling fan mechanicals and/or electronics.

As I mentioned above, the first check would be to make certain that the connection between the fan control module (inside the car under the glove compartment) and the power steering pump is in place and that there is no damage to this wiring connection.