I have a 2003 Discovery SE7, the vehicle whistles when under acceleration. It does not whistle when I lift off the accelerator.

I have seen two or three other threads asking the same question, but unfortunately, the original poster persons have not posted a final resolution.

My first instinct was the main drive belt (serpentine) was slipping. I replaced the belt with a brand-new high quality OEM belt. The vehicle still whistles under acceleration.

Grateful for any useful commentary. Thank you.

 

For those interested, I took the 2003 Land Rover discovery to rover doctor in Martinez California. He diagnosed the whining as the U joints in the front driveshaft. The original equipment you joints do not come with grease fittings. He installed a new driveshaft with greaseable U joints for $500 including parts and labor. Also, it fixed the "clunking, jerking" that I was feeling when the transmission was under load.