location of temp gauge sensor?

[jimmy02flames]

I searched but it seems theres maybe more than one coolant sensor. The interior dash temperature gauge in mine frequently shows red hot shortly after egine starting and I belive there is a malfuntion in the reading versus an actual overheating.
Anybody know the location (and which one it is) of the sensor that controls the gauge? Im wanting to replace the sensor to see if this fixes problem

[Kep]

Where the water hose comes off of the engine on the driverside to the top of the radiator there is a cluster of sensors. I believe that the one you want is on the bottom on the opposite side of the blue sensor with two vaccuum hoses.

However, if the temperature returns to normal after a while I would also suspect the thermostat. Check the manual for details on how to check each of these. A regular mechanic's thermometer that you screw into the housing or one of the newer infa red thermometers would also help to isolate the problem.

Kep

[atobe]

it's the last one to the left on the top row of 3 sensors

[88 LE]

^ water temp sender

[jimmy02flames]

Thanks for that pic, That should do it.
I'm almost certain its not the thermostat as I've chaged back to original and its still doing it.
Oddly however I never had any problem with the reading untill I did change the thermostat last winter. I
1 changed themostat last winter for more heat with no reading problem evidnet then
2 began having this reading problem,
3 suspected the new thermo was overheating engine,
4 changed back to the old thermo and the overheating/reading probem still persists where there was never a problem to beging with last winter.
Its like the new thermo last winter ruined the old sensor

[Mike Gerber]

Originally Posted by jimmy02flames

Thanks for that pic, That should do it.
I'm almost certain its not the thermostat as I've chaged back to original and its still doing it.
Oddly however I never had any problem with the reading untill I did change the thermostat last winter. I
1 changed themostat last winter for more heat with no reading problem evidnet then
2 began having this reading problem,
3 suspected the new thermo was overheating engine,
4 changed back to the old thermo and the overheating/reading probem still persists where there was never a problem to beging with last winter.
Its like the new thermo last winter ruined the old sensor

Are you sure you have properly bled all the air out of the system? An air bubble can cause symptoms like this. I would download the manual for your generation and check the coolant sensor that feeds the gage in the dash against the specs in the manual. You will need a DVM for this. If that checks out normal, I would thoroughly bleed the cooling system.

Mike

[88 LE]

My EWD manual shows 2 makes of sensors. Nippon Denso and Yazaki.


Nippon Denso
-----------------

1 - ground:

Approx. 226 ohms at 50C (122F)

Approx. 26.4 ohms at 115C (239F)



Yazaki
---------

1 - ground:

Approx. 152.7 ohms at 60C (140F)

Approx. 26.4 ohms at 115C (239F)



The readings (1 - ground) are taken between the body of the sensor and the tab (what the connector from wiring harness plugs onto).

[jimmy02flames]

man thats great ideas bout bleeding the system and checking the sensor against the specs. I had not thought about bleeding coolant system and the sensor costs $30 and I'm really not sure the sensors causing the problem.

How do you bleed a coolant system?
And when you say I need a DVM that is just an Ohm Meter?
Where do you download a manual from?

also

The car symptoms are
1 only after starting does car read red hot only for first few minuts. Never shows hot later unless restaring
2 Doesn't always do it. Maybe 1 start in 20.
3 When it does read red hot, after a few minuts it rapidly (2 secs) falls to normal
4 been doin this since last winter begining with 1st thermo change & continues with 2nd&3rd

[Doctor J]

You can use cooking thermometer to estimate engine temperature
Disconnect the wire from the sender and observe the gage.
If it still reads high the problem either the wire from sender to the dash gage is shorted to the ground or the gage itself is defective.
One time the similar condition on 84 Camry was caused by defective sender.

[Mike Gerber]

"How do you bleed a coolant system?
And when you say I need a DVM that is just an Ohm Meter?
Where do you download a manual from?"

To bleed the system start with the engine cold. Park the car on a slight incline facing upward. The front of an inclined driveway will do it. Remove the radiator cap and start the engine. Let it run for 45-60 minutes at idle. You will see air bubbles coming up through the removed cap area. After about an hour, top off the coolant mixture and replace the cap. Some usually bubbles out through the cap area. Drive the car normally and recheck the coolant level in a day or 2. You may have to add a bit more coolant.

Yes, that is just an ohmeter.

The manuals are stickied at the top of The General Camry Discussion Forum.

Mike