Recently my 2nd gen '86 rx7 non-turbo has been trying to overheat due to a leak somewhere in the cooling system. The weird thing is I just got it out of the shop and the guy said he couldn't find anything wrong. I just put in a brand new radiator and replaced all the hoses and caps and seals. My theory is that when the engine is reaching a certain temp it starts dumping water out of the cooling system into the overflow tank, in the top of the tank there is a small breather hole and all the pressure is pushing the fluid through that hole. I'm not sure though, if you have any suggestions please let me know! This car is starting to tick me off!

 

did you check for bubbles in the coolant when the car is running and cold?

 

What would that do?

 

start the motor when its cold and remove the rad cap, if you see bubles or it gushes out when its running then you have bad coolant seals witch would require a rebuild

 

Thanks man, i'll check it out!