Coolant overflow tank overflowing...
 

The last few times I've driven the car, I've noticed that the coolant level was a little low in the filler neck. I haven't gotten a chance to investigate it much, but I had just assumed there was a slow leak. Yesterday after a drive, I shut the engine off after letting it idle for a few minutes, and about 5-10 min. later, I noticed a long trail of coolant leaking from under the car. After searching for the leak, I found that the coolant overflow tank was where it was coming from. So here are my Q's

Is there supposed to be a vent in the coolant overflow tank? Near the base of the "neck", there was a hole which all the coolant was leaking from. I wasn't sure if a plug had come loose, or if that was there as a vent.

Could a bad pressure cap cause this? This was the first time something like this has happened, so maybe the cap went bad and isn't holding pressure after the car is shut off?

Where is a good place to get a cooling system pressure tester? I've read that it requires some kind of special adapter for our cars.

Does this sound like a weak o-ring? The car is never hard to start, and I get a little smoke on startup, but smells like burnt oil.

hey ya, I had the same prob, replaced the cap on the ast and that fixed it for a bit, but mine turned out to be a water seal..... the hole at the bottom of the neck of the ast should have a pipe attached to it. hope that helps mark

When I've had this happen, it has always been a result of failing coolant seals. Sorry.

Check out this thread...

https://www.rx7club.com/showthread.p...at+big+coolant

Dave

Wow, I guess I'll start looking into rebuilding the motor.....just bought the car in December. I guess this gives me the chance to port it, dowel pin it, modify the cooling jackets, etc. I'm hoping the housings aren't warped. The motor was rebuilt at an un-named shop that I later found out is a pretty bad shop. There was supposedly a verbal warranty, but I don't trust them at all to tear the motor apart, but I guess there's little to lose?

Does anyone have experience with the block weld method explained on the rotary resurrection site? I know this is a band-aid fix, but I'd like to get the most miles out of the motor while I save money for the rebuild, and before the motor really goes to shit.