Still looking for PINGING source...

[slo95]

I have to ask again, because this is getting ridiculous. I think the spark predetonation finally blew a head gasket (another post). I have crazy big time engine ping under load ONLY when the car is warmed up. On my way to work in the morning, I can stomp all I want, and no noise(ping) - until the engine warms up to say, the "ORM" part, of the stock gauge. Also only happens warm, at WOT, under load. Stock 95 GT, tried 6* to 10* timing, no diff., 185* thermostat, gas octane makes no diff., cleaned the EGR/IAC/new ECT/cleaned the connectors, all the usuall. NO Codes.

1. I was thinking air or fuel pressure related (leaning out), but wouldn't that cause problems all the time, no matter what temp? So I think that is out.

2. So now I think cooling system related? Not enough flow thru the block/heads to keep them cool enough not to cause excessive heat and pre detonation? Think a new radiator would do it ( I am flushing it tomorrow, need to measure internal coolant loss) ? water pump is not leaking or squeaking.
also does not over heat, but the upper radiator hose after the car is warm is hotter that sh!t and hard to squeeze.(pressurized)

Any ideas? (Nothing like trying to pass someone with the car making all sorts of noises - embarrasing to say the least.)