first off ... i should have named this thread "vanishing coolant" or something because i'm sure that's where most of my problem lays.

anyway, in a nutshell, i seem to be losing antifreeze and i have no clue where it's going. it's not leaking and from what i can tell, it's not being consumed during combustion. so where the hell is it???

FACTS:
my cooling system is virtually new (with the exception of the reservoir and the hose running to it, no part is more than 14 months old thus far). i run a 13 psi radiator cap (CST). i'm running an aftermarket 180* thermostat (but i just bought a MAZDA thermostat and it should be installed within 2 weeks). i run Havoline antifreeze with distilled water (though i've probably replaced about 50% with tap water through my constant topping off) i don't drive the car hard because i can't afford to break something (plus the clutch has given it's 2 weeks notice).

if i fill the radiator and reservoir today, the coolant level light will be on in 7-10 days - that's what's happened thus far. the light comes on when it's cold, but has never stayed on after the engine warms up - at least, not yet.

i bought my radiator from www.radiators.com last September and i'm seeing a rusty residue in it already. also, the temperature fluctates from day to day (as indicated by factory gauge - for what it's worth) - but it generally stays higher than i've been used to with my previous Rx-7's.

i haven't been on in a while - i know you probably never even noticed i was missing. it's because i'm not home now. i don't get to go home often, and i'm only saying this because it means i don't get to log in often or check the board - so please keep that in mind if you're going to ask me specific questions about this dilemma.

PLEA FOR HELP:
the temperature crept into the bad zone today just going to class (about 4 total miles, stop-n-go). so even though the annoying light would be reason enough to **** me off, i'd like to get other ideas and opinions on where the coolant may be going and how to get my temperatures down to what i consider more normal levels.

thanks

 

Are you sure the water jacket hasn't been compromised? Thats what it sounds like to me.

 

if your burning coolant i think you will get a more then normal amoutn of white smoke from your exhaust mebbe even smell a bit sweet. do you think that could be the case?

 

does the overflow stay full? those cst caps are are inconsistent, some of them hold 13psi and some of them dont.

mike

 

thanks for the responses guys ...

to: syclone and pedestrian x~

well, let's put it like this, if the water jacket has been compromised, then it's such a small crack that the coolant leak isn't constant and that the combustion pressure does not enter the cooling system to an appreciable degree. the only check i've done thus far is to run the engine with the radiator cap open ... i haven't tried to do a CO test on the antifreeze, so i'd be lying if i said i've exhausted all options there. other than that, the only way i'd know is to yank the motor and pull it apart and i can't spare the downtime right now. i'm about 3 hours away from home - so i need the car daily.

to: j9fd3s~

i've suspected the cap before, but i have 2 of them, though they're both CST. i have one 13 psi and one 18 psi. but to answer you question, no ... the overflow does not stay full. i haven't measured how long it takes, but i'd estimate that it runs below the pickup tube every 6 to 7 weeks or so. if you don't mind my ignorance, what would that mean? that it's just the cap?

i would like to note, and i'll try to be as brief as i can (i promise ) - the reason i had changed the radiator is because the car started to run hot last summer and since the original radiator seemed rotted, i got a new one. however, up to that point, i had never experienced what i'm experiencing now, rotted radiator and all, but the 13 psi cap was on that radiator from last January and on top of my daily driving, i drove the car from NY to FL when i moved - and the temperature never became an issue until months later.

 

Like many have said, check the cap. Some even hold about 10!!!!!

 

if the cap is bad it will boil and want to fill up the resovoir (sp?), so the overflow, will stay full

mike

 

is the water pump new? have you checked the little hole to see if the coolant is leaking out the pump? just a thought.

..Sean

 

I had a similar problem and it was that the radiator was starting to block up. Have you had anyone test the radiator yet? Given the damage that overheating does to a rotor I wouldn't be driving around if you can avoid it...

I could be way off but I have read many times that the thermostat will show you're in trouble way too late... i.e. after you've already damaged the engine.

Best of luck sorting it out mate :-)

Matt