I have a 2000 four winns 4.3 GL, when you shut it down it hums kinda like a A/C equalizing on a car, but louder. It sounds like it might be coming from exhaust riser, or hoses from flame retarder to exhaust riser. Any ideas??
You are going to have to be the one to tell us what exactly is humming, We can't listen to it from a computer desk.
Get a mechanics stethoscope and check each part until you find out where it's coming from.
