OrangeGlo

If anyone could help me it would be great. It started when i bleed the coolant line going to the tb and ran the car before putting more coolant in it. When i put in more coolant it went down to normal temp. so i thought it was fine... I took it out the next day and i drove fine for the first 10 mins or so after a warmup to operating temp. then it overheats. If i drive it on the highway or something the temp. goes back down to normal temp. If i let it idle or sitting at a light the temp starts climbing again. It has good cold start and idles perfect until it starts to overheat after 15-20 mins.

Mahjik

iTrader: (1)

Have you replaced the thermostat?

OrangeGlo

no that was the next thing on the list.

OrangeGlo

it doesnt sound like a blown seal tho right? I just got the motor about 5000 miles into it.

wrankin

not to ask the silly question, but you did make sure all the air is out of your cooling system, right?

DaleClark

iTrader: (55)

If you do replace the thermostat, ONLY use the Mazda thermostat. I've seen Stant parts store thermostats fail in a few MONTHS. Not worth it!

Dale

OrangeGlo

yes i "burped" the bubbles out. What i dont understand is you can keep squeezing the radiator hose and fill it with more coolant but it just goes into the overflow tank past the "f" mark.

Trexthe3rd

Where are you filling the coolant at, the ast or the filler neck??

OrangeGlo

the neck

Trexthe3rd

You do know it could take several days of short driving and filling to completely burp the system right? (unless you have a coolant burping tool). It's unlikely to be the thermostat, if it is than you would be overheating regardless of what speed your going.

zullo

Don't try to fill your system with the AST cap off:

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/tip-topping-off-coolant-317377/

OrangeGlo

ok i replaced the thermostat.. it didnt do anything. I smell coolant and thats not good! what exactly are the symptoms of a blown seal?

OrangeGlo

thnx for the thread but i dont try to fill it with the cap off. would air in the system cause me to overheat like this?

AdrenalifeRX7

turn the heat on full and the blower on full and bleed it with the radiator cap off till ALL the bubbles stop

zullo

You said you keep adding coolant and it goes right to the overflow bottle. The only way for that to happen is if you have the AST cap off or you have the wrong cap on there. A pressure-relief cap on the AST is required.

And yes, air in the system is the culprit with many overheating problems. One thing to try that I do that seems to help... find the steepest grade you can find and drive your car on it - up and down, turn around etc. I have a local hill with 8-10% grade where I take the car after a coolant change. The cooling system that otherwise acts full often comes back from the "hill treatment" needing to be topped off - hope it helps, ymmv

OrangeGlo

ok i got a hold of a burping tool and all the bubbles are out...but i noticed the fans arent kicking on! I think thats the main source of the problem now. thnx for ur help guys.