I took my Miata to Laguna yesterday for the Miata 20th anniversary event. The first session it was fine, but on the first lap of the second session, it was going sideways trying to put the power down coming out of turn 11. At the time I thought it was just cold tires, but now I suspect it was coolant. I took it easy for the next half lap, then in turn 7 I got the meatball flag. I pitted, and there was steam going everywhere. There was a two inch rip in a small coolant line (the one going from the factory water/oil heat exchanger to the back of the head)
After it cooled down, I bypassed the line, put a gallon of water in it, and restarted the car. It was blowing steam out the tailpipe, which others said smelled like coolant to them. (It didn't to me, but it's unclear how much actual coolant is left in the system at this point, it's probably mostly just water). It was also spiking the factory water temp sensor into the "red" zone, even though it hadn't opened the thermostat yet (aftermarket guage is mounted outside of the thermostat, so showed zero). Worried about a blown head gasket, I had it towed home. Yay for AAA plus. My leakdown tester is broken, so I borrowed a friend's today to try it. Alas, the hose on this one has longer threads than mine and I was unable to get it to seat the O-ring against the head, so there was pressure leaking past the threads. Clearly the numbers are not very useful in an absolute sense, but hopefully they're at least useful relative to each other. Leakdown numbers were 90, 75, 75, and 90. No bubbles in the radiator, nor out of the crankcase (at least, not after letting the pressure push the piston down, then wrenching it back up to TDC). There also didn't seem to be air coming out of the adjacent cylinder's plug hole, although that was hard to tell for sure. The engine was completely cold. I managed to put a bunch more water in the radiator today, so the "overheat before thermostat opens" at the track could just have been caused by air in the system, I guess. Any thoughts? --Ian _______________________________________________ Miatapower mailing list [email protected] http://list.miatapower.net/cgi-bin/mailman/listinfo/miatapower
