Anyone out there ever had this problem before. If I start up my car and drive off the thermostat opens normally, but if I start it up and let it idle the thermostat does not open. The temp gauge just keeps climbing. I just replaced it with a new thermostat from the dealer and it still does the same thing. I was going to check my tsp setting and just needed the car warmed up, but now I have this problem. Any ideas?

 

How do you know the thermostat is not opening? Did you start it cold with the rad cap off and look for flow when it gets warm? Or it could be the water pump is not flowing enough, either weak or the belt is loose. (Can you see any residue at the weep hole?) Or the fan clutch is shot. Either way, it cools when moving just by the airflow. A little more detail might make it easier for the guys help you.

-John.

 

well, you will know if its closed, just put your hand on the upper radiator hose (carefull, its hot!) and you can feel the coolant rush through it.

 

I know the thermostat is not opening because the heat gauge is going up and the radiator is ice cold. I can squeeze the top radiator hose and it is cold and no flow. I'm new to working on rx7's, could the water pump impeller be slipping?

 

I don't know why you don't replace the defective thermostat since you know it does not work?

 

He said he replaced the thermostat with a dealer replacement; that's why I mentioned the water pump. Other than what I mentioned, how would you check it?

-John.

 

FJ, sorry about that. I'm a economical reader. Only read part of the posts. Anyway I just know what I'd do right this minute. I'd go out to the car and rip that thermostat out and put it back together without a thermostat and start the car up. What are the results???? Oh, and do everthing FJ said. A good question is, *does it overheat when driven?*. If not, and only at idle, then you need to take a good look at that fan clutch.
Cheeez, misread another post!