My rx8 is overheating when the A/C is on, when its off it stays pretty cool. With the A/C on it will get really hot then cool down to normal then really hot then cool down, you get the idea. Also the fan stays on like 10 mins after i turn the car off. It seems to be leaking coolant because i have to put in like a qt every week but i dont see it leaking in my driveway but i can smell it when i drive. I was thinking thermostat but im new to the car and rotary engines. any advise would be appreciated.

Thanks,

J

 

Check the fan fuses up front.
If the fuses are ok, pull out the aicleaner box, so you can see the rad fans.
One fan should always be on whenever the a/c is on, the other kicks in when the gauge rises past normal......

S

 

I have a feeling you have air in your cooling system.

make sure its bled properly.

 

would air in the cooling system cause it to loose coolant?

 

how do you know it's overheating? Is the needle moving? (if so, be very careful...the car is heat soaked at that point)

Check the fuses, sometimes it can go and without the 2nd fan kicking on, the car is going to struggle to stay in its operating range.
70k, ever had the radiator flushed?

 

Yes it would

also, like jedi asked, have u ever flush your coolant ?

 

Just bought the car bur according to the guy i bought it from he just replaced the radiator, he gave me a bs story about why but i wasn't worried about it at the time. Ill have to check the fans tomorrow. I know it gets hot because the needle goes up, never let it actually overheat.

 

unfortunately with the RX-8, by the time the needle moves, you're already overheating. The needle doesnt move until your car is already over 220°F (or is it 230?....I forget)
Which radiator did he put in there? another OEM?
If he swapped out the raditoar, he might not have replaced the foam that goes around it, that helps quite a bit.

 

that is the problem

Its either not OE replacement. or he never bled the air correctly.

OE Radiator is actually better than a LOT of aftermarket Radiators. Also, its not hard to bleed the air for this car, but many morons never even heard of bleeding air.

Take a picture of your raidator. its not that hard. Just take the airbox out and you will see it