my car started to overheat yesterday for no reason, and it won't hold any water. my first thought was freeze plugs but i can't find them. i also checked the radiator and everything else. help please.

 

Is water leaking from somewhere? The freeze plugs are on the back of the rear iron, so if one came out, you would have water coming out from between the engine and transmission.

 

If it won't "hold" water, than it is leaking somewhere. Track down the leak and fix it.

 

have you checked waterpump?

 

Borrow a coolant pressure tester from the local autozone or advanced auto and pressurize to find the leak.

If it's a coolant seal, the coolant will only be seen when you remove a spark plug and crank.

 

My RX has its temp guage at around half or a little past half, is that high cuz i would imagine so. and i have a leak at the higher/top radiator cap, think there is a crack in it, a very very small one cuz i see very small bubbles come from just below the cap but not from the gasket. well anyway i need to find out where i could get one of these to replace it and the correct gaskets while im at it.

P.S. the bubbles come from the the tube the cap seals off not the cap itself.

 

The engine's "freeze plugs" are a misnomer for core plugs, which rarely leak. Just pressure-check the system to find the leak.

Do you only see the bubbles when you open the cap, or is the coolant bubbling out of the system?

You can get parts from the dealership or from online shops like Mazdatrix.

 

Coolant is bubleing out of the super small crack when hot and with the cap closed

 

Could it be that the motor started running really lean for some reason? It's just a thought that came to mind besides all the obvious

 

That is very plausible. Because I recently screwed around with the Idle fuel ratio but now my car suddenly doesnt over heat. Although the thing is, last time i filled up the coolant tank I filled it about and inch higher then the Full mark, and it then rose up to the cap later on, it was fine at this time, I turned the bleed screw and some air came out and after that my car heated up. Lastly I looked at the tank later and it was at the low mark. and after adding some more coolant to bring it back up to exactly the full mark it doesnt over heat now. The gauge now sits comfortably around 1/4 to little more then 1/3.

 

Playing with the variable resistor and getting a lean idle would not have anything to do with the cooling system. If the system was not bled properly, pockets of air will reduce the effectiveness of the system. This means higher temps.

 

Ok my car still does over heat and I found out it was a combination of things.

1 - A fuse I have for the Electric fan burned out and thats what caused the car to over heat more then it normally did.

2 - Coolant was very low, like ridiculously low, had tons of air in the system. I tried bleeding it out but it wasnt enough so i popped the upper cap and saw no fluid!!! So I had to add about 4/5ths of a gallon to get it full.

Apparently the last owner broke off the over flow tube at the upper cap and lost alot of fluid, then decided to not replace the part, shove a golf tee into the hole, and plug up the end of the hose with a bolt. and leave it like that.

Because of the constant high temps resulting from the missing coolant. the fan had to work at high RPMs to try and get it to cool down. this in turn burnt out the fuse and also wore out the fans motor. now I need to find out exactly what kind of fuse this is and get another one and probably have the fan fixed or replaced. (it makes a rattling/squeaking noise now and doesnt even spin as fast as it used to)

 

Sounds like you need a new fan if it doesnt spin as fast as it used to. The cooling system in an RX7 is very important. You need everything to work fine because even overheating a rotary engine once could cause severe damage. If other people have over heating problems try checking for a leak, replace the thermostat with a OEM thermostat, check the coolant level, and make sure hoses/radiator isnt clogged. Thats all the idea I can think of right now, its been a long time since Ive been in the rotary business

 

Overheating on these cars is an issue as it was with my 650 horse power SRT-4. My best bet was a lower thermostat, upgraded radiator, and also increased raditor piping sizes.

 

Have you done any basic cooling system troubleshooting?

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

But if water is leaking from somewhere, the system will not properly pressurize and end up full of air. This will certainly cause overheating.

Lower temperature thermostats are just a bandaid.