Ive been troubleshooting the squealing coming from my engine, and its getting really annoying. Ive replaced the tensioner pulley, and the idler pulleys, the sound is still there. Ive taken the belt off, and ran the engine for about 10 secs, and the sound is still there, one of my friends who is good with trucks said it might be a vacuum hose, but i just dont know. I have a 93 C1500 4.3L V6. I need to know if i can fix it myself, and if its cheap to fix. Please help