I know how to adjust the belt, that isn't the problem, may be I haven't explained myself well enough. If I adjust the belt when it is hot to the correct tension, then check it again when it's cold I have one and a half inches of slack at the longest point, so much so there is a flapping noise when I run the engine which is the belt hitting the thermostat housing under the cam pulley and it is wearing a groove on the back of the belt. NOT the indentation that occurs in the middle of the belt from the contact with the tensioner