I have a '98 Ranger, 2.5L L4, 5-speed that is in really good condition that I have had for about 5 years. It has 131,000 miles and runs like new. Lately, though, when I am driving, if I take my foot off the accelerator and let the engine idle, I can hear this really weird squeaking noise that sounds like squirrels going “nuts” under my truck. I also hear the noise when I am backing up. The first noise seems to come from the front of the truck, while the latter noise, when I’m backing up, seems to come from the rear of my truck. Also, the noises seem to happen only at low RPMs and low speeds, although because of the engine noise when driving, I can’t really tell if it makes the noise then or not. Any thoughts? Thanks!