Does anyone know how long your engine will last if you're having hydraulic lifter problems before you have to replace them? I have a '02 Mustang Coupe that has had this problem over a year. It just makes the clackety sound when you turn the car on, after a minute the noise subsides.

 

or it could be piston slap

 

how bad would it be to drive a car that needs a head gasket...say you buy the car and drive it home and then don't drive it until you get the gasket fixed