1987 e150 van......... warmer the weather longer the serpintine belt squeal, have changed belts to no avail.......suspect tension pulley.........if so,can pulley be lubricated?

 

If you have the 4.9L I6, sometimes the water pump weeps onto the belt and will cause the squeal. You might need a water pump.

 

Had same on an 88 E150. Changed belt, still noise. Tensioner marks were where they should be. Look at the bottom of the tensioner, where the internal spring anchor hole is (end of spring sticks out). Mine had worn into a ragged slot about 3/8 " long. Result was proper position (between the marks), but limited tension. Spent a bit of $ at NAPA and an hours time, no more noise.

 

will inspect tensioner ASP ....... mentioned you spent $ at NAPA,meaning you purchased new tensioner? I sure appreciate your reply Thanking you much.............