I have worked in a few GM dealerships and it's scary how many times I've heard the "technician" diagnose a car with wrist pin knock...
Fixitman: I had a co-worker a few years ago that bought a newish (03?) Impala for $100 because it had a "Junk Motor". Turned out it was the flex plate. He's driving that car still. Total investment, $100 - car, $25 - flex plate.
haha