A mechanic was removing a cylinder head from the motor of a Mustang when he spotted a well-known heart surgeon in his shop.

The surgeon was there waiting for the service manager to come take a look at his car when the mechanic shouted across the garage, "Hey Doc, can I ask you a question.

The surgeon, a bit surprised, walked over to where the mechanic was working on the Mustang. The mechanic straightened up, wiped his hands on a rag and asked, "So Doc, look at this engine. I open its heart, take the valves out, repair any damage, and then put them back in, and when I finish, it works just like a new one. So how come I get such a small salary and you get the really big bucks, when you and I are doing basically the same work?"

The surgeon paused, smiled and leaned over, and whispered to the mechanic......"Try doing it with the engine running."