Do not spray anything on a serpentine belt. Sprays are designated only for v belts, read the label. I don't know how many times I've our Mexican friends or redneck idiots trying to fix shit in the worst way and do this (usually with WD - 40). Then their car sits in my parking lot and I have to have it towed because the belt gets thrown off all the pulleys. Then they come in a week later and complain to me about how they are poor and cant afford the bill. Then I say "Well Sir (or Ma'am) if you had listened to me when I explicitly told you not to spray that on your belt, none of this would have occurred. Then they say "What does "explicitly" mean?".................