I recently bought a 96 outback with a bad motor, and the very first time I started it (it was cold, hadn't ran in a few months) the temp gauge instantly went right up to regular operating temperature. I thought this was odd.

 

I ended up swapping in an EJ22 for reliability purposes, and I thought that this would possibly solve the problem, but it did not. The temp gauge still rises right up to operating temp as soon as you start it. My only logical thought is that this is the actual gauge cluster? Any suggestions?

Could be a problem with the temp gauge sender?

Only if the temp gauge sender is not on the motor. I swapped in an EJ22 that came out of my Brighton, and the gauge was working fine before.

sound like the gauge would be a good guess. unless a previous seller tampered with it or the wiring to hide an over heating engine condition. not likely but check the wiring maybe. i don't even know if it is possible to to tamper with it.

 

did you run the previous engine enough to see the gauge go to hot?

Yea I did. Lol. Let's just say the EJ25 motor was making rod knock noises, and I was more concerned about not towing the automatic than I was saving that motor. So it got really hot and started smoking like crazy. It looked like a jet was taking off from the highway, it was so bad my friend following me had to pull over and let the smoke clear. It was also spewing coolant out of the overflow tank, and the gauge said it was at normal operating temp. So I know for sure that the gauge was incorrect.

So I know for sure that the gauge was incorrect.

 

so swap it out. it could maybe be in the wiring, but not the wiring on the engine. so unless you see something obvious swap the gauge.

It would be pretty shady, but perhaps someone wired in a resistor to fake a signal ot the gauge.

 

I'd say swap the cluster, and if you see any funny wiring in there look to see if it goes to a resistor. I'm guessing a 300-500 ohm to make the gauge sit right at the middle.

 

man that would be shady.

You're right Gloyale...that would be very shady.

 

Try disconnecting the sensor and see if the gauge moves. I think the gauge should show cold when you do that. Shorting the lead to ground should make the gauge show hot. If the gauge doesn't move doing those things then the sensor wire would appear to not be connected to the gauge and the gauge is tied to a different path.

Edited February 25, 201016 yr by Cougar