Mechanics

FAN SWITCH

1998 Toyota Corolla

Engine Cooling problem
1998 Toyota Corolla 4 cyl Two Wheel Drive Automatic 110000 miles

The car is running hot in low speed situations. I replaced the left side cooling fan motor, which was dead. I also replaced the thermostat and the coolant temperature switch in the thermostat housing. It is still running hot, and I am thinking there must be a separate fan switch somewhere, but I can't seem to find it. Do you know if there is one? And where it is located?

Thank you. Mike
Avatar
Mkulina
August 23, 2010.



The sensor is located in the left side of the engine, below the exhaust manifold.


http://www.2carpros.com/forum/automotive_pictures/561653_Cooling_fan_sensor_98_Corolla_1.jpg


Wrenchtech
Aug 23, 2010.
I know, it looks just like an header, and it fooled me at first, but it was hooked to the air cleaner!

So it's in the front side of the engine. On the block or cylinder head?

And thank you. I really appreciate your help.

Do I have to tell you, this is the daughter's college car and she left yesterday?

Mike

Tiny
Mkulina
Aug 23, 2010.
It looks like it's in the block. It should be pretty obvious.

Wrenchtech
Aug 23, 2010.
I'm going to check, the longer I look at it, the more it looks like the temperature sensor which is located in the back of the thermostat housing. If it is, I have replaced that.

But I have not replaced the cooling fan relay and that may also be an issue.

It hard to diagnose on a car that keeps disappearing from the driveway.

Thank you. Mike

Tiny
Mkulina
Aug 23, 2010.
Throwing parts at it is not the solution. It needs to be troubleshooted systematically from a wiring diagram.

Wrenchtech
Aug 23, 2010.
You are right, I have been trying to eliminate the issue by working through waht I thought was the proper sequence. That sensor is the one in the thermostat housing and evidently it supplied the ECM with infor as well as controlling the fans.

The fan motor was worn enough to where it was brushing the radiator fins, so that haad to be fixed. I'm just not sure what the next step should be.

I broke down and bought an alldata subscription for it and will continue from there.

Thanks. Mike

Tiny
Mkulina
Aug 23, 2010.
Follow the wiring diagram. Post back if you need something on the diagram explained.

Wrenchtech
Aug 23, 2010.
I'll give that a try. And I'll let you know how it goes. Mike

Tiny
Mkulina
Aug 23, 2010.
What did you discover? I am trying to diagnose a similar issue on a 1995 Corolla.

Tiny
Paulronco
Oct 7, 2012.