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High Pitch Sound While Vehicle Is Running


Charter Member
SM 2003
Full Member
Jan 23, 2002
Forked River, New Jersey
:8: I noticed a high pitch sound coming from my 2002 Z71. The sound is somewhere under the truck. As I look for the sound orgin, it is more noticible in the rear. The sound I hear comes when my truck is running at idle. I noticed the sound yesterday when moving out of a parking space while my window was open and the radio off parked next to another vehicle. Once I start driving I cant hear the sound. What is it??? :8: Please advise.
Electric fuel pump inside the tank. :B:
I have noticed this myself. I don't notice the sound when the tank is full, only when it is low. Also, when the tank is at just the right level, I can hear it change intensity as I hit the brakes, due to the fuel sloshing around in the tank and covering/uncovering the pump.

This whine is normal and very typical of fuel injected engines where there is an electric fuel pump in the tank. To one degree or another, I have heard this in every fuel injected car/truck that I have owned. (7 and counting, including a Chrylser Lazer :-[ All the rest are Chevy :B: )

-- SS