ok, so im a newb, i own a stock 79 RX7 (12a engine) with about 66K miles and i just got it out of storage with no problem. This is my second summer with it and its been great. I have a general understanding of rotarys, but I want to be sure I'm maintaining it right.
The last 2 times I drove it, the "add coolant" light would come on for a brief second then go away. My coolant level is fine, and my temp gauge tells my everything is fine, no overheating. Could this be a bad sensor? Or maybe a restriction in the cooling system? I should mention the times it came on, I was giving it a bit of gas, but I wasn't abusing it (staying between 6-8 thousand RPMs). Am I just being paranoid?

 

I've had this happen one too and just had to top it off a little. What was happening to mine is that the light would go away once heated, so by the time water started expanding and actually hit the sensor. wasn't much but was enough to give it that reading.

 

It's drawing the coolant down a little from the acceleration, is your overflow bottom working / filled to where it should be? I had an issue with a crack in my cap seal and it would spray slightly over the battery (caused a small rust issue) when I accelerated. Was hard to figure out since it wouldn't leak any other time.

 

That happens to me sometimes. I have a very small leak on my radiator, but not enough to worry about. After a few months the coolant light will come on occasionally until the car warms up for a minute. I just top it off a bit and it's fine after that.

 

"but I wasn't abusing it (staying between 6-8 thousand RPMs)"
;D
so, by your definition, "abuse" starts at 8100rpm?? Yike!
may be a bit on the high side for a... 25 yr old...? motor my friend.
Stu Aull
80GS
Alaska

 

Check the sensors on the rad and the seals on them. I had this issue and it was as simple as putting an o-ring under the sensor ontop of the rad.

 

lol, yeah... well i rarely go to 8000, usually no more than 6000. My buddy in highschool had an 86 rx7 and he would go to 8500, sometimes 9000! I usually judge or define abuse with whatever he does with cars, hahaha. Anyways, thanks for all of the advise guys

 

Permanent engine damage is almost guaranteed if you spend any time at or above 8,000 (8,400 is the "critical" point of no return according to the FSM). Really nasty stuff like e-shaft warpage, spun bearings and rotor edges contacting your rotor housings.

You want to stay below 8 if you value your car at all. Below buzzer if your engine is still the stock engine.

But you're definitely abusing it. "Not abusing it" would be shifting well before the redline buzzer.

Either way, keep checking and topping off your coolant, and make sure that your coolant resivoir works. Mine didn't, the valve had clogged from years of neglect. I bought a new one at Mazdatrix.

Jon

 

My FCs used to. it was a bad coolent sensor connection on mine.

 

My 79 did that for a while too. It seemed like the coolant was plenty high enough, but once I topped it off, the light went away. I suggest topping it off til you can't get any more coolant in the rad. I think that'll take care of your problem.

 

That's a good point.... Coolant sensor sitting atop the rad might have a bad connection or be going bad itself. The previous owner of my car had gerry-rigged a crappy connection on the sensor, so once I fixed mine by soldering on a bullet connector I was fine.

Jon

 

I know this is a little off topic but i don't know what these guys are talking about with the over 8000 rpm is bad. maybe be a strech for stock because your exhaust is stock you will not have power that high of rpm yet but these cars are built to red line. just as long as you take proper care of the motor the more gas you get it and out the faster you go. I have a header to full open exhaust with no cat a mod clutch some other small mods and my powerband is all the way up to 8000 and i'm not scared to go over. My car is a 79 with many miles but the motor is strong. the harder i drive my r the more she likes it. Don't be scared of the redline just have fun!!