2 Locate the serpentine belt tensioner. It is located below the alternator on the left front side of the engine. The tensioner on the 3.4 liter, 3.5 liter and the 3.9 liter engines will require a 3/8 ratchet to release the belt tensioner. The 3.8 liter engine will require a ratchet and a 15 mm socket for the belt tensioner. I thought I'd make a thread for how to replace the serpentine belt for the BK1 3.8 L V6 Genesis Coupes in case it helps someone. ... 2010 Genesis Coupe GT 3.8 Auto. ... removal of the air intake is a must, give you a lot more room and clearer view for the job. Thanks for the belt diagram and the picture of the tensioner pulley, it is easy to be ... Picture and diagram for how to Replace Serpentine Belt on 3800 V6 in many Pontiac, Buick, Chevrolet and Oldsmobile car models. Picture of serpentine engine drive belt routing for the GM 3.9 liter V6 engine in Chevy, Buick and Pontiac cars. When replacing your cars drive belt , use the diagram ...