i live near highway. so when i am in a hurry in the morning, i don't fully warm up the engine. i take the car on the highway and let the V8 do it's thing.

when i push the car hard, the light would come up, then in 10-20 seconds later, the light goes off. but it only happens when the engine is cold. and it only happens once during the first 2-3 min of driving. once the engine is warm, the light doesn't come on.
this problem was there even before the mechanic pointed out about the leak. but i didn't think too much about it because i manually checked the oil level and it was fine.