temp guage always reading HOT

[Peanutibutter]

Okay my temp guage sits at c ool for several seconds and goes straight to hot and it has new sensor but I didn't buy it or put it in. So what's going on??

[robertpaige]

Well, you need to have a few more specifics.

Do you think the car is actually getting hot? Have you checked your coolant levels? How long is 'several seconds?'

[Peanutibutter]

30 seconds tops

[Peanutibutter]

From when I start it

[mike-tracy]

Which sensor did you replace, the one with the 2 wire plug or the single blade connecto

[Peanutibutter]

I didn't replace it the guy I got it from I'm guessing and its the single blade

[mike-tracy]

For all you know he could have replaced the other one. The blade one is suspect IMHO.

[Peanutibutter]

My dads knows subis and he says it new and what's IMHO??

[Legacy777]

If you're absolutely sure the single blade sensor is a brand new sensor from Subaru, I'd suggest checking the sensor's resistance to make sure it's good. These scans are from the overseas factory manual, but the sensor readings will be the same.

http://www.main.experiencetherave.com/s ... n-USDM.zip

At around 122 deg F the sensor should have a resistance of around 187.6 ohms. Measure the resistance between the blade and the engine block. If you measure the resistance when the engine is "cold" the resistance should be higher.

If you are getting readings that are in line with the manual, then I'd check the wiring from the sensor to the dash.

Here are the wiring diagrams for the 1990 Legacy. The dash temp gauge sensor wiring is in there.

http://www.main.experiencetherave.com/s ... agrams.zip

The wiring should have 0 ohms resistance. If everything checks out ok, then I'd suspect the dash gauge may be bad, but I'd suspect the sensor or wiring first.

[robertpaige]

My dads knows subis and he says it new and what's IMHO??

It's an abbreviation for 'In My Honest Opinion'

I would go to the dealer and get new sensors just to make 100% sure. They aren't expensive.

[Peanutibutter]

Legacy777
I don't know if its a subaru sensor

[robertpaige]

I think your best off replacing them with OEM sensors since you didn't buy them or install them and then go from there.