Originally Posted by izzy_crazy

So i have a 95 rx7 and have had an issue arise twice. under normal driving conditions the car will all of sudden heat up and start steaming from the overflow tank...... . also the gauge shoots up to about almost the red .... any advice or solutions are very much appreciated and thank you for your time

Originally Posted by shift 7

....does anyone know at what temp the fans kick on? I was thinking around 180-190

Originally Posted by The_MC

..... I'm having a similar problem, I've replaced pressure caps & replaced coolant and bled system up then when I ran engine it warmed up but thermostat didn't seem to open till way too late and the fan came on but by then it had got too hot and pushed the water out of the overflow bottle. I did the champagne test with a funnel after that when the engine was cold again and didn't get small bubbles at all just a few big ones which I'm guessing was from the loss of water?

Any thoughts would be awesome. Im thinking new thermostat.

Originally Posted by Sgtblue

A coolant seal failure is a common problem....at least in the FDs of which I'm familiar. IMO it's the price for forced induction. Boost is power. More power= more heat= more stress. NA rotarys have the problem, but AFAIK, not nearly as soon as the FDs.

Still, before doing anything, make sure you have a failed seal. Besides the 'Champagne test" these are all the symtoms I can think of... but no single symtom by itself is confirmation. Many symtoms could be from other causes. However the more symtoms/conditions you have in combination, the more likely it is a coolant seal failure.........

*Stumbling idle on cold start-up that clears up quickly. The combustion chamber is fouled with coolant. As soon as it's purged or burned up, your car will run fine until the next cold start.
*Slightly sweet exhaust smell, especially on start-up. See above. Coolant is being burned and it has a distinctive smell.
*"White smoke" (steam) on cold start-up even in warm/hot weather. See above.
*A coolant over-flow tank that is over-flowing. This will usually result in a puddle under the car near the right front...the area of the over-flow tank. When coolant gets hot it expands and that's what the overflow tank is for. But with a failed seal the nature vacuum that forms and pulls that coolant back out as the engine cools down is lost. That leaves that coolant stranded in the tank and eventually it overflows.
*Coolant loss that isn't explained by a puddle on your garage floor. It's being consumed by the engine and going out the exhaust.
*Spiking temps that seemingly recover on their own almost as quickly. Air pockets in the cooling system allow steam to form. That will cause temp spiking. This is different than a rising temp just after a period of hard boost. It can happen as your steadily cruising down the highway.
*Boiling sounds after shut down even shortly after properly "burping" the system. See above.
*Failed coolant system pressure test.
*Failed test of coolant for hydrocarbons.
*Unusually clean plugs, or wet plugs if you pull them right away after starting the car. (Sometimes you can even smell the coolant)
*One or more episodes of serious overheating in the car's history regardless of miles. (from what I've read, 115 C./240 F. seems to be the critical number for OEM seals to begin to degrade)
*An otherwise well maintained and cared-for FD approaching 100K miles or so.

As for a bandaid, some have used one of the many "Stop-Leak" coolant additives to give them a bit more time but use at your own risk. While it's not anything that will leave you on the side of the road, a failed coolant seal can lead to errosion/rust/pitting of the coolant seal grooves in the irons. That can cause a junk iron and make the inevitiable rebuild more expensive.