By November 6, 2006 1 Comments Read More →

Temperature Gauge Jumps Around

I have a Firebird, 3.8 V6 with 125,000 miles. Once it’s driven a little, the temperature gauge fluctuates rather rapidly. At a single red light the temp will fall from 240 to 170 or visa a versa. It seems to be constantly moving either up or down. Since this is my son’s car, I can’t tell if this has been going on for awhile or just started after having the radiator flushed. Any thoughts on (1) bad temp. sensor ( 2) bleeding air out of colling system (3) anything else.

Thanks for any assistance

Hi Donnie,

My first thought is you probably have a bad “temperature sending unit”. You can buy this inexpensive part at any auto part store and you can replace it yourself rather easily. It screws in the engine, usually on top of the manifold or on the side of the engine block and is connected with usually a single wire lead.

This is not the same as the temperature SENSOR, that is for the computer. The temperature sender sends data to the dash gauge. There is a possibility in a bad dash gauge, but that is rare, the sending unit is pretty common complaint.

Austin Davis

About the Author:

Austin Davis, consumer car repair advocate. "Hi there! I love to help people solve their car repair problems and I hope my site was helpful to you today. Thank you for stopping by."

    I have the same vehicle, my gauge does the same thing, it’s usually low until I stop in traffic etc.,then it rises, but it doesn’t overheat.