I agree it seems difficult to find an honest mechanic when your car is doing things that it shouldn't and it only seems to do those things when you are driving and not when the mechanic is checking it out.
For the turning off problem, if it is not giving any kind of check engine light when it turns off, then I believe it is probably caused by the Crankshaft Position Sensor. If the resistance thru the sensor falls outside the acceptible range, the power to the ignition circuit will shut down. These sensors have been known to cause intermittent shutdown of the engine only to allow the engine to be started again. It usually takes 5 to 15 minutes before it will restart.
Good luck to you. There are many more honest mechanics out there than most people think. Especially when you have a problem and they don't seem to have a clear procedure in their troubleshooting guide that pinpoints the part or parts that is the cause.
It only took me 1 1/2 years to get a correct diagnosis on my car's engine shutdown problem. The one thing I could always count on, "It would always start up for me within 5 to 10 minutes".
Thursday, May 13th, 2010 AT 2:58 AM