Idle Overheating but ok with A/C running? - Toyota Nation Forum : Toyota Car and Truck Forums

94CamryMan · 01-16-2009, 08:01 AM

So when I'm idling my engine starts to overheat. But if I flip the A/C on and set the fans to high and blow hot air, the radiator fans come on and cool it back down to operating temperature. Any ideas what could be causing this? Thanks.

***new echo owner*** · 01-16-2009, 08:05 AM

Check the coolant fan switch if the radiator fan don't come on by themselves.

N.E.O.

Stillrunning · 01-16-2009, 08:08 AM

Sounds like engine cooling fan is not activating. Test fan by disconnecting fan switch on lower rad hose (engine off first), fan should come on with switch disconnected. If not switch then possibly relay.

94CamryMan · 01-16-2009, 08:11 AM

Yes the fans come on when I disconnect the coolant fan switch.

***new echo owner*** · 01-16-2009, 08:14 AM

Probably a bad switch, it there is sufficient coolant flow to the switch.

N.E.O.

94CamryMan · 01-16-2009, 08:19 AM

I would assume there is only because when I turn the A/C on the engine cools down. But I'm not positive that's proof of good coolant flow.

sbushnak · 01-16-2009, 08:52 AM

What year and engine do you have?

I had the same problem in my 97 5sfe. I checked the switch, sensor and relays and all tested good. I changed the thermostat and it fixed the problem.

I only drove about a 1000 miles and so far so good.

Stillrunning · 01-16-2009, 09:16 AM

So fan does not come on when engine temp climbs at idle? No overheat at speed? Test resistance of switch. Could be bad rad. Not sure if it's stat as engine cools when A/C on. Seems sticking stat would cause overheat but fan would also work.

94CamryMan · 01-16-2009, 09:10 PM

I tested my cooling fan relay today and I'm getting continuity between contacts 3 and 4 but apparently no continuity between 1 and 2. On my multimeter it read about 730 and I was getting no sound. So I guess this narrows it down to my relay? If so can a relay be fixed or is it better to just shell out the $50 and buy a new one?

***new echo owner*** · 01-16-2009, 09:39 PM

If the fans come on with the A/C or when you disconnect the fan switch, it sounds like your relays are working. Which relay did you test, there are three different ones for your car.

Here is the wiring diagram link for your car: http://www.camrystuff.com/manuals/Ge...ry94wiring.pdf

N.E.O.