coolant leak on a GT3 - engine damage?

[Harris_I]

Just my luck. My second track day with the GT3 on the superb Dubai Autodrome and I have to head home in the morning session AGAIN! As last time, hopefully nothing too serious.

Coolant leak meant a tow truck home, but I'm just curious: given that I slowed down when I smelt the coolant, and switched off the engine as soon as the warning light came on, and given that there was a barely discernable amount of coolant left in the visible portion of the bottle when I parked up, what chance is there of permanent engine damage?

I understand from a fellow Porschephile that the coolant temperature gauge is irrelevant when coolant has leaked out since it measures the coolant temperature (funnily enough!), therefore one cannot be sure what the actual engine temperature was.

Assuming I had been driving hard for a few minutes whilst the coolant was leaking, and for another couple of minutes like a granny after I suspected something was up and before the warning light, how much of a buffer do Porsche build into their warning systems to avoid a catastrophic failure?