I have a 1999 Mercury Mountaineer with a V8 engine. When I start thew car up, I get a whine like metal-on-metal. Every time I go to my mechanic, he puts a large metal screwdriver on all the different parts under the hood & can’t find where the noise is coming from. When I step on the gas pedal, the whine gets louder. When I’m cruising, the whining gets softer, but doesn’t go away. Please help.
Look for a driven accessory, like the alternator, idler pulley, a/c compressor, etc. that’s making this noise. If you’re low on power steering fluid, this can also make a noise like this. A transmission with a failing pump or clogged filter can make this noise too. Try taking the drive belt(s) off and briefly start the car to see if the noise is gone. If so, you’ve at least isolated the noise to something driven by the belt.
Thanks for the info. Will try.