[IHateHacks]

I would place my bet on a blown exhaust gasket. Either manifold to head, manifold to down pipe (front pipe), or front pipe to cat. But, 99.9999% of the time the exhaust gasket blew because it overheated and warped the gasket surfaces. I'd say either the exhaust manifold or head surface is warped.


Or (as it was in my case) theres that .0001% chance there are one or more stripped threads where the exhaust manifold bolts to the head. I had to helicoil 3 on my supra.

Same thing happened to me when cold, tickin like a ford; when warm, pretty much ok. That is because the basic law of physics or whatever states that as a molecular structure retains heat, it expands (in an exhaust manifolds case it fills in the imperfections of a warped surface) and as a molecular structure cools it contracts. And im not saying it fills it in perfectly and it depends on how bad its warped.

Good luck!