WTF my car is overheating....I cant post in the technical forums til ive been a member longer so Ill state my problem here. My car is over heating, its not losing any coolant, and its not smoking, there isnt any water in the oil, it isnt the radiator caps, there is no air in the system, im pretty sure it isnt the fan...The car ran great and just started getting hot out of no where, it was soo hot it was boiling in my over flow tank. Anyway, now it gets pretty hot and levels out, but still maintains a temp hotter than normal, its stays about 3/4 up the temp gauge. What do you all think? Thermostat? Water Pump?

 

Does it only do it while you are driving, only while stopped, or all the time?

 

I had the same problem but only in idle. The quick fix I did was to hotwire the radiator fan to a switch. Although I installed an aftermarket radiator/fan. You should see if the fan even turns on during idle.

 

i'm guessing by the user name this is an 88 vert in question? unless u or the previous owner installed one, it doesn't have an electric fan. i'm kinda leaning towards the t-stat since the description suggest it's running hotter while driving but overheats sitting still. when water pumps go bad they usually start leaking, they don't make it run hot. at least not in my experience.

 

What risk am I taking by purchasing a Beck Arnely Thermostat instead of going to mazda? I dont like Stant so i will not purchase one of those either way, but what harm if any does the Beck Arnely pose? Also, i have a 13psi springed cap on my radiator, and a non springed cap on the filler neck, is this spec?

 

No info on a Beck Arnley t-stat, but that's just a generic brand. It might be fine, or it might open at a completely different temperature. Whichever cap has the overflow tube connected under it HAS to have a spring. The other one is just extra.

 

well I went to change out the thermostat and to my surprise there was no thermostat in place. This would probably explain my cars erratic cooling behaviors. Now to see if having the new Tstat in place will fix the issue. If only the bolt didnt break off in the filler neck flange, id be done

 

Well my car was overheating like i posted before, with no consistency. I found there to be no thermostat in the car so i installed one. Now the car seems to be running a little better and not overheating, well not as bad. Now it only gets hot if i drive it on the interstate, (maintained higher speeds) but it doesnt get all that hot, i mean it doesnt peg out the temp gauge but it definately gets too hot for comfort. Also since ive installed the thermostat it seems to consistently idle a little higherr, it was always at 750, now it hangs around 1000rpm. anyone have any ideas? the car isnt losing coolant as far i can tell, which tells me it prob isnt the water pump, i burped the air out of the system, the fan works, the tstat is new...does anyone have any ideas?

 

If it is overheating on the freeway like that, then I would suspect a slipping belt on the waterpump, or a blockage in the radiator.

You should probably also check the timing, as too much advance can lead to overheating.

Good luck....



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

 

+1 on the radiator. have a radiator repair shop flow test it to see if water flows thru it like it should to keep the engine cool. flow rates for radiators is gallons per minute. depending on the size, the flow rating is anywhere from like 15 or so to well over 20 gpm. can't remember exactly cause it's been a long time since working in a rad shop but i think these flow somewhere around 17 or 18 gpm.

 

from my knowledge of rx7s. at least second gens anyway, using a mazda oem thermostat is always the best. ive had multiple different thermostats on my last second gen and none of them stopped my overheating problem like the oem one did.

 

I appreciate all the insight and I will post my results as I get them. As for the guy who said it might be the head gasket...WTF. this is rx7club.com meaning Rotaries!!!!!!!!!