Lexus Repair: leaking exhaust pipes, blown head gasket, exhaust pipes

Question
The smoke coming from under my hood is white. I was told by you that it is probably leaking coolant(leaking exhaust pipes). How would I go about fixing it, or how big of a job and how expensive?
Thanks

Answer
It depends on where the coolant is coming from & which engine it is. It will be an internal engine problem.
Normally it's a sign of a warped cylinder head & blown head gasket. Sometimes people get lucky, and it will be something mild along the lines of an intake manifold with coolant passages will have its gasket wear out.

I would warm the engine up & do a compression, or leak-down test to rule out a head-gasket/warped cylinder head problem ASAP.