well im having a concern bout a boosted d16z6. everytime i really get on her for long periods of time....lets say highway full bore....balls to the wall. after i get done doing the "road runner thrust move" coming back down from high speed, the temp gauge goes absolutly nucking futs. but during normal driving, no matter how long im driving and under moderate boost, its fine. its only after going nuclear that she does this. its got me confused. at first i was thinking it was the head gasket, so i replaced that.....still does it. theres no oil in the coolant and vice versa. now granted this is only a temporary motor for the next 3-4 weeks when i get my motor done....AGAIN....so im runnin it at 12 untuned. the little d has taken a pounding, and shes held up extremely nice for being untuned, and having 140k miles on it. my concern is you think this is something that i should keep and eye on, or just let it go. considering it only does it when im frickin really moving.