76 280z. at start up no smoke... then after a minute white smoke start coming out for 3-5 mins or so. then no smoke.. what could it be? im not sure if the smoke is oil burning or water burning.... it's hard for me to tell the difference

Man, sounds like slight head gasket leak. Any of the plugs look different?

Ben's Z might be on to something. I had an external water leak between the head and the block that would seal up when the engine got warm. The cooling system held pressure fine when hot, it just leaked a small amount of hot water while the engine was heating up and cooling down.

I just replacded my plugs today bc my other plugs were foul.. but when i pulled the foul plugs today it was wet. Every single one of them. And it wasnt like that 3 days ago. I thought it was oil but it ddnt really feel like oil... My car doesnt overheat.. i drove the car probably 30 miles today after i changed the plugs so ill pull them to see what they look like and if they are wet.

Also would a little leak cause a slightly low compression on all cylinders

Any air bubbles when its running,or oil in the radiator?

Sounds like you've got a blown headgasket to me. Just starting, but it is unusual that it would occur in all the cylinders at once.

Did you smell them? They could be wet from the gasoline.

What does the smoke smell like?

No unusual odor = exhaust steam

Sweet = coolant

Somewhat like bacon = oil

Pungent and black (makes your eyes burn) = excess fuel

I agree with others. All plugs looking the same suggests something besides a blown/leaking head gasket. If the plugs are fouled with gasoline, it could be an EFI issue.