lol same symptoms as my car. i thought it was a HG too but turned out i have 2 cracked pistons. if you check my thread the gasket isnt made THAT poorly... could be better. but i had a rough idle, loss of power, smoke out the mack of my car.... all HG symptoms. honestly you never know what it is sometimes unless you look under the hood yourself. or pay a shop a bunch of money.
http://www.toyota-supra.info/forums/...omorrow-6.html