I have a 98 integra gsr and replaced my radiator with a mishimoto full size dual-core over the summer. The temperature outside is now below freezing, and I noticed that the temp. gauge is fluctuating while I'm driving.

If I was on the gas for a decent amount of time on the highway, say @ 3500-4000 rpms, it would get close to operating temp., but never quite got there. When I wasn't on the gas, say going down a hill @ the same rpms, the needle on the temp. gauge would drop further towards cold.

Is anyone else experiencing this issue? I'm planning on parking it for majority of the winter, but is it safe to drive if it never reaches operating temp.?

 

sounds like you have a bad thermostat to me.

 

Ditto that ^^^ the rad does not control engine temp, the thermostat does. 94

 

Three years. No problems.

 

Thanks for the input guys. I just thought it was weird that it just started doing this when the temps outside starting getting colder, kind of like the rad was working over-efficiently and not letting it reach opperating temp. It never once did this in the summer. I guess I'll look into a new thermostat

 

it didn't do it in the summer because it is stuck open. the air going across the radiator was never cold enough to bring it below operating temperature.