Started my 96 4-cylinder straight drive Tacoma this morning and it sounded like rocks rattling around in the fan belt area. I thought waterpump, and a drive around the block seemed to confirm that, as the temp gauge rose quickly. Upon returning home and turning off the ignition, however, the truck continued to crank as if I were trying to start it. This lasted for 20 seconds or so. I had been having trouble with the clutch switch (which completes the ignition circuit), so wonder if these two events (if I have diagnosed them correctly) are unrelated?
I believe you need to install a new water pump. Engine overheated which caused dieseling(attempting to run) after you turned the ignition key off.