Car is a '84 240 turbo. It sat for a couple years and then in-tank and main fuel pumps were replaced; in-tank was supposed to be an upgraded model. After a couple short drives (basically from mechanic home), there's a buzz from pump area. Mechanic says its the main pump working too hard because in-tank pump failed--after less than 20 miles??? He says it was ruined by the old gas in the tank. (Some fuel was added after the pump was replaced, but the old gas was not drained).

Is this a plausible explanation?? All I can think of that would make the old gas "bad" is water in it. I can imagine that, but the car ran fine--how could that be if gas had enough water to damage the pump? (Actually, is it plausible that even a lot of water could kill a fuel pump that fast?)

The mechanic is a Volvo specialist and is supposed to be good, but this sounds very flaky. He says he'll replace it under warranty, but there will be "some labor" involved. And if it is true, shouldn't he have drained the fuel before replacing the pump?