Pulled up at 6:40 a.m. and the serpentine belt announced me so loudly the customer opened the door before I hit the steps… I’m swapping the belt and checking the tensioner after dinner with a 15mm and a breaker bar — lesson learned about inspecting it every oil change. Anyone else get accidental sound effects from putting off basic maintenance for one shift too many?
Had the same ‘doorbell’ last month — before you throw on the new belt, pull it and spin every pulley by hand; my idler felt sandy with a hair of play and fixing that killed the squeal. Does it quiet after a minute or keep hollering?
But before you grab the 15mm, hit the belt with a quick water spritz — if the 6:40 a.m — squeal fades, swap it; if not, chase pulleys and alignment, @ryahall’s spin test included. Also check the tensioner’s wear indicator and watch the crank pulley for wobble.