the coolant cap seal is torn and not sealing the coolant correctly, which then triggered the coolant fill light to come on. i filled it and the light is off. has anyone else had this problem? is there any reason to believe that my motor was damaged? sorry im just very concerned

 

do you monitor coolant temps?? that would be the way to find out if it has overheated.

i dont think its really anything to get worked up over. i say just order another oem cap w/ seal, put it on, see what happens. you need it replaced anyways

 

Did the buzzer come on while you were parked? Or driving down the highway? How long before you were able to shut off and fill with coolant?

On one extreme you'll be fine. On the other it could have overheated. I would replace the cap with a new one from Mazda, refill, and see what happens.

Dave

 

If your engine did not overheat then you should not worry. As far as the cap seal, please keep in mind these cars are 15+ years old, the rubber will eventually become brittle and break. I have a spare brand new never used OEM cap it's yours for $20.
PM me and we can arrange for payment and shipping.

 

it didnt overheat at all. my stock engine temp gauge was normal, and my power fc read all normal levels (84-90). and it was only when i stopped. maybe i overfilled the res. coolant tank? i did just buy another coolant cap or i would have def. taken your offer. should i have of gotten an aftermarket one or a stock OE cap? thanks for your time guys. when i leave work today ill see if it has corrected the problem.

matt

 

Cool man!! Good luck!!

 

I'd get the OEM cap. The aftermarket caps don't have as good of a reputation.

Dave

 

well its not leaking from the cap anymore, it seems to be leaking from either the resevior tank, or a coolant hose. or maybe the radiator? im going to jack it up tonite and try and see where its coming from. any advice? maybe the res. tank is cracked? its still throwing the dreaded "add coolant" light but is still not over heating and it only does it at a stop. its still pulling 16Psi of vacuum at idle. the motor isnt dead yet is it? im losing my mind

 

DON'T DRIVE IT.

When you replaced the cap and it continued to leak you should not have driven it any more.

Put it in the driveway and don't move it until you find the leak. Or tow it to a shop that can find the leak.

Dave

 

Hey friend, I had the same problem, check this thread out:
https://www.rx7club.com/3rd-generation-specific-1993-2002-16/my-fd3s-overflows-antifreeze-when-parked-hot-after-being-driven-745566/

 

ok, i checked out the thread and it helped me understand the coolant system better. but i believe the leak is coming from the hose that connects the AST to the overflow tank. its pouring out at random, sometimes its not leaking at all, and sometimes it leaks about a cup of coolant. i wish i wouldve read your post sooner about not driving it, but as i was leaving, once again, the coolant light came on right after i filled it. and i was going to a friends house to look at it, when the temp gauge started to rocket up. i immediatlly pulled over and turned the car off. and then when i got out almost every drop of coolant in my engine was on the ground. whether or not it was from the overflow tank i dont know. i filled it again and pushed it back up the street to my house. filled it back up, jacked it up and started it up. thats how i found the leak. and it didnt leak out the way it did before but still leaked a little. its not the exhaust pressurizing the coolant because the coolant overflow dipstick doesnt have a black goo on it. what else could make this problem??? thanks guys

 

and the power FC has a water temp gauge, would the actual thermostat itself need replacing?

 

It's a 15 year old engine, I would definetely recommend replacing the Tstat. I would also recommend changing your AST with a Pettit AST here's the link:
http://rx7.com/store/rx7/fdengine_cooling.html

 

ok ill try that. is it the AST thats forcing the coolant out? it even drained it from my motor..

 

i also have a 16psi coolant cap..should i use a 13psi instead?

 

These are the culprits in making coolant overflow:

Bad thermostat
Bad AST
Bad coolant overflow tank
Bad hoses
Bad caps
Bad engine O seals (It sounds like yours is OK)

The overflow tanks develop a crack on top where the hose from the AST connects. When you check out the tank it looks good, however, when it is very hot it expands thus coolant leaks out from the top.
When I had this problem I would park the car in the garage and I would loose half a gallon of coolant, it drove me crazy. So I did the research on this site and I replaced everything including hoses. When it comes to the cooling system of the rx7 do not skimp on replacing old components it is not worth loosing an engine.

 

One more thing; make sure your overflow tank is at the recommended level. If the level at the overflow tank is too high and you have issues as you mentioned if the AST is releasing pressure and your tank is full it has no place to go but to spill out from the hose connection or a crack ontop of the overflow tank. Correct coolant level in the overflow tank is a MUST...

 

16 PSI caps are good but you need to replace the OEM AST with the alluminum Pettit AST and all the associated hoses. The OEM AST is plastic and it breaks at the seams, if you allow it to break you will loose your engine when it overheats beacuse it will drain all the coolant out within seconds.

 

Yes, the old ASTs are not worth a crap. If you read my other thread you'll see what I did and it solved the problem. Also when adding coolant back in you must burp the system, i.e. remove all the air out. The best way is to use the yellow funnel that I used, it works like a charm.

 

It sucks having this coolant spill problem, but it is fixable!!

 

thanks guys so much, ill replace the Tsat, the oem AST with the pettit aluminum one, overflow tank, hoses, and caps. ill keep you guys posted on how its going. ill post some pics too of the car and the coolant system. you guys are the best

 

No problem... glad to help. Keep us posted.

 

I suggest you get your hands on a cooling system pressure tester before running the car again. You can rent/borrow one from many auto parts stores, and it will fit an aftermarket AST cap. This way you can find leaks without destroying anything.

Dave

 

ok ill try that now, what sort of reading am i looking for? will this help me pinpoint the leak? it seems to only leak when it gets hot (85-89c) and its leaking down from the bottom of the overflow tank(about a half a cup if not less).. and just a few little drops other places.

 

The idea is to pressurize the system cold. It should hold 15psi for a very long time, and until it does it should make the leaks easier to find.

Dave