My 98 ex is overheating only when I drive and the heat is off. I can not figure out why I just put a new tranny In it and now it's over heats. Any ideas?

 

Did you bleed the coolant of air properly?

 

Try bleeding the air out of the system by taking your radiator cap off (when completely cold, obviously), and running the engine. See if the fluid "burps" out a couple of times. Keep an eye on the radiator fan to make sure it's cycling on/off, and also check to make sure that both hoses get equally hot once the thermostat opens up.

It's going to be something simple..trust me.

 

Alright guys I tried to "burp" the system and it seems to have worked but I am from central ny and driving with my heat off is a struggle but I have it a shot it usualy overheated on my from my apart to the gas station which isn't a far drive 5or 10 mins round trip so I started it and let the car warm up and drove to class and sat there over 10 mins total of the car running without heat on and my needle went to half way and stayed there. So I think I am good I will keep you updated and ask any questions if I find anything else

 

Did you bleed the system with the heater on?

 

Will OP fall into the trap?! Stay tuned to find out!!

 

Is proper procedure to bleed it with heater on or off?

 

The suspense builds......

 

Lets say the heater core is empty...you bleed it with the heater turned to cold...then you drive and turn the heater on..where does that air go? Back into the rest of the system.

Yes bleed with mixer set to hot

 

Yep. You don't even have to turn the fan on, just make sure the temperature slider is all the way hot. That'll open the valve and let coolant circulate through the ENTIRE system.