Whistle Noise From Tank While Driving

[timothytimmons]

Hello To All,
I drive a 1999 740I. While driving i hear a whistle noise coming from i am assuming the fuel tank. It makes a hi and low pitch sound. It's starts from 35mph. If the radio is on, you don't hear it. It's not very loud. Please help.

[georgebest]

Hello To All,
I drive a 1999 740I. While driving i hear a whistle noise coming from i am assuming the fuel tank. It makes a hi and low pitch sound. It's starts from 35mph. If the radio is on, you don't hear it. It's not very loud. Please help.

Could it be the drive shaft?

[Mayorchuck]

Fuel pump or check valve if it's gas tank related. Pull up your rear seat and go for a drive with someone sitting in the back, listening to the passenger side where the pump and valve is located.

http://www.bimmerboard.com/forums/posts/110831

[timothytimmons]

I removed the rear seat and it is coming from the fuel tank. Now i have to figure out if it's the check valve or fuel pump.

[jclausen]

The only whistle noise I ever heard in the v8 was when the pcv plate fails on the back of the intake manifold and pulling the dipstick will cause the noise to stop