I have a weird cooling problem with my '95 Integra SE. Last summer I started noticing that my temp guage always read a little on the cool side, and the needle would drop when I would downshift for engine braking while coasting down steep hills.

This winter it seemed to be taking a long time for the heater to warm up, so I decided to have the thermostat replaced. The dealership said the coolant temperature was stable once the engine was warmed up, but I had them replace the thermostat anyway. That fixed the heater problem, but the guage still reads a little cold, especially when coasting in lower gears.

Yesterday I noticed that when the heater is off, the temp guage now reads normally. This is really weird to me since the problem started last summer when I obviously was not running the heater. Any ideas about what this could be? My next step is to check the coolant temperature sending unit, but I would think a bad one would cause the guage to read funny all the time. Thanks in advance for any help you can give me.

 

The stock temp sender and gauge aren't all too accurate to begin with. After you've checked the sender, you may want to look into an aftermarket water temp gauge.