Lately, as the weather has been getting cooler, so has my car. In the summer, if I drive, like on the highway or backroads with no stops, the temp guage stays halfway between 100 and 220. If I park, or do a drive-thru or something, it will get to 220 and stop there.

Now, I made the trip from CT to NH last night, and the temp guage didnt get any higher than this. But If I stop, it get warmer untill it hits 220. When I start driving on the highway again, it will creep back down to where it is in the pic. Which is good because it seems to pull alot harder at the lower temp. But I dont want to hurt my motor.

 

Thermostat stuck open and reallly clean stock radiator??

 

Sounds like theres no t-stat. It probably pulls harder because you get richer AFRs as the computer exits closed loop and gives a little more timing.

 

Maybe low on coolant?

 

No theres plenty of coolant, and its like brand new 50/50. I powerflushed it with the everwear machine when I worked at a shop this summer.

The t-stat might be open, havent checked it. Probably the origional 1990 t-stat.

And the radiator is stock. And really clean. When I was flushing it at work the lead tech came over and used the droplight to look down the cap nexh, and his comment was that "the car must have been in a front end collision because the inside of the radiator looks brand new." But the car has no signs of collision repair, and everything under the hood has signs of being 17 years old. Maybe its just the low miles I bought it with?

 

I'd say it is a stuck open t-stat or removed t-stat cause no air is going through the radiator when stopped. When you hit the highway, air is flowing through the radiator cooling the coolant. A removed t-stat will have coolant running through the radiator all the time.

 

if you didn't replace the t stat after flushing it is most certainly stuck open from debris. you can get a infrared noncontact thermometer(pyrometer) from sears for 20 bucks. run the engine for a half hour and verify guage and vent temp readings. my vote is still for the stuck open t stat though

 

ya know i have the same thing. I think it's not a big deal. Does it take forever to warm up in the morning? If no then it must be that cold, but the t stat should regulate that. I know there is 0 gunk in my whole engine and radiator so maybe it just cools that good? I don't think it will hurt anything. I believe the engine runs hotter anyway b/c it helps keep engine sludge down. or that's what i was told.