Temperature Question - Toyota Nation Forum : Toyota Car and Truck Forums

zppeacock · 10-13-2010, 09:42 PM

My 1994 Es300 1mz, when its over 60F the temp gauge goes to a normal position around half way, any thing blow 60F even 2 degrees the gauge drops to about a 1/4 not the normal half. Its got the hydro fans which run slow all the time and increase when needed.

Anyone ever had this occur before?

Image is after being driven for a hour highway/city mix.

Chris Crash · 10-13-2010, 10:05 PM

My gauge on the 94 with hydro fans does the same thing and it bugs me.

***Mister_Perkins*** · 10-13-2010, 10:22 PM

could be because your fans are running all the time ?

If your getting good heat in your cabin and your reservoir is full I would think that it is working correctly.

You said it runs at a normal operating range at certain temperatures so a thermostat that is opened all the time is out of the question.

I would have to say that the fans running all the time is probably a factor. just a guess though

I've seen gauges running like that quite a bit, but its usually linked to "I have no heat in the car" as well

There always is the possibility that your sending unit for the gauge is going bad too. You may want to check the temperature switches to see if they are working properly. I think there are two on the thermostat side. Dont quote me on that though

The top switch should have continuity only when cold. Worth a check i guess

just looked it up

rusty9 · 10-13-2010, 11:27 PM

your thermostat may be stuck partially open, if it stays there while on the highway. otherwise i'd say its the sending unit.

pmesfun · 10-14-2010, 02:25 AM

I have that same problem, it started today after driving on the highway, going back and forth to the airport. So it is possibly the thermostat then?

Chris Crash · 10-14-2010, 10:13 AM

I also assumed it was the T-stat. I was gonna change it soon anyway.

But right now...I've got more important things to fix.

***Mister_Perkins*** · 10-14-2010, 10:22 AM

Quote:

Originally Posted by pmesfun

I have that same problem, it started today after driving on the highway, going back and forth to the airport. So it is possibly the thermostat then?

could be a T-Stat or a temp. sending unit. There are two switches right where the T-Stat housing is. Check both of them. the upper one will have continuity when cold.