1989 BMW 325 6 cyl Two Wheel Drive Automatic
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After I drive my car for a while, I can hear what appears to be the fuel pump whining. I've put 2 new pumps on and both have done the same thing. I also changed the filter. I drained the gas tank, but there was no noticeable debris in the gas. Driveability doesn't appear to be affected when this occurs (no loss of power and/or acceleration). Is the fuel suppose to whine like it's doing? Could it be something else, possibly the power steering pump?

Sounds are very difficult to diagnose from cyberspace. If the pump is noisy, there should be a reason, is the tank deformed or dented?