IS THIS A BAD THERMOSTAT OR ENGINE TEMPERATURE GAUGE PROBLEM?
1990 Nissan 300ZX
June, 22, 2012 AT 4:42 PM
I have a 300ZX with 147,000 miles. When turning on the air conditioning, the engine temperature gauge rises to the top. When I turn off the air, the temp drops back to normal. Is this a bad thermostat or engine temperature gauge problem?
Suspect cooloing fan or radiator effeciency reduced to calcium buildup in core
June, 23, 2012 AT 3:07 PM
If the gauge shoots up immediately and cooling fans works, it would be an inaccurate reading due to a bad ground circuit connection, behind the headlights.
July, 15, 2012 AT 9:28 PM
Most likely this would be caused by a bad ground connection.
July, 16, 2012 AT 10:10 PM
Thanks for help. Replaced clogged radiator, power washed the air conditioner condenser. I could not believe the road crud that washed out. While I was there I replaced the hoses and thermostat. To my surprise, the thermostat had been removed. There wasn't one. I bought this Z used. Previous owner must have had overheating issues as well. Not sure what fixed the problem ( maybe all of the above) but temp gauge is level no matter if air is on or not and it is 110 degrees out.