A couple days ago i replaced a bypass hose to my water pump and I clumsily spilled some coolant on my serp belt and alternator. Since then I have been hearing an annoying squeaking noise when the truck is at idle/off the gas. Also my belt is a little old but I would imagine that if it was my belt, the squeak would be constant not just at idle speed. If anyone knows about this problem at all, any input helps. Thanks! ( 1992 Ford F150 5.0 )

 

It's your belt due to the antifreeze acting as a lubricant. Spray some WD40 at the inside of the belt with the engine idling and the squeak will go away or you can VERY CAREFULLY hold a cake of bar soap against the inside surface of the serpentine belt with the engine at idle and the squeal will soon stop. Tip: cracks appearing in the serpentine ribs do not indicate a bad belt, but several missing segments of these ribs does mean it is time for replacement.