[Joelb251]

It is possible the piston rings in the cylinder with no compression could be stuck, but I do not know the full story, so I can only guess. If that is the case, I think you would smell fuel on the dipstick when you check the oil. a stuck valve could cause a loss of compression, but you would probably have a popping noise either out the exaust or from the throttle body, depending which valve it is... I am curious to hear what the mechanic says the problem is...