When I drive it on the highway for more than 10 minutes, the temperature increased nearly to high. I checked it yesterday and found no coolant . So I bought coolant and add some coolant more than "Full" . But the temperature still increase. What should I do? Is that the problem because I add much more coolant so the temperature still increase? Or maybe it caused by other problem.

Hope you would give me some advise. Thanks.

 

Is the coolant disappearing? Basic things you could check/replace are leaks in the coolant system, pressure cap, thermostat, and waterpump. More info is needed to help you.

 

stop driving it if you see it getting hot. you can seriously damage your engine.

 

did you mix the coolant with water, 50/50? sorry if it's a dumb question, it just seems kind of hard to tell from your post. pure antifreeze won't work as effeciently as a mixture, and could cause higher temps.

 

Afer I added the coolant yesterday, I drive for 20 minutes the temperature is still increasing. I drove it today, the temperature increased. Then I checked the coolant. The level of the coolant is lower than yesterday. I am not sure it is due to the overflow of the coolant or coolant leaking or coolant seal. How can I check them? If it is due to the overflow of the coolant, that's fine because now the level has lower than high. If it is due to the coolant leaking how can I check it? It is MAZDA RX 7. Which place should I check?

 

Yes, I did buy the 50/50 mixture. So that won't be the problem of pure antifreeze.

 

is it overheating while you are moving at speed

or stuck in traffic?

 

just the temperature increased nearly to high. Because I only drive for no more than 20 minutes so the temperature didn't exceed high. It didn't stuck in traffic.

 

You have a cooling problem, you're obviously not mechanically inclined.... take your car to a shop...

If you want to fix it yourself, realize it will probably cost you more to do it yourself (learning isn't free!) and take a LOT longer than a shop... and possibly you could screw up more things.

First step is to diagnose... since you don't know how the cooling system works, that will be very hard to explain/understand. So unless you're heavily inclined to do it yourself... take it to a shop.

--Gary

 

http://www.aaroncake.net/rx-7/cooling.htm