Recently the truck started making a high pitched ringing noise when in Park or Drive but it goes away when I apply the gas. Right now it's intermittent but is happening more frequently. Everything else seems fine. Any ideas?
Thanks. Just got it back from the dealer. It was the serpentine belt tensioner. They said the belt itself was fine but I had them replace it anyway because the truck has 158,000 miles on it and I don't want to have to pay them to take apart the front of the engine all over again when it wears out.