A mechanic was removing the cylinder heads from the motor of a  car when he spotted the famous heart surgeon in his shop, who was standing off to the  side, waiting for the service  manager to come to take a look at  his car.

The mechanic shouted across the garage,”Hello Doctor!! Please come over here for a minute.”

The famous surgeon, a bit surprised, walked over to the mechanic.

The mechanic straightened up, wiped his hands on a rag and asked  argumentatively, “So doctor, look at this. I also open hearts, take valves out, grind them, put in new parts, and when I finish this will work as a new one. So how come you get the big money, when you and me is doing basically the same work? ”

The doctor leaned over and whispered to the mechanic…..

He said: “Try to do it while the engine is running “.