I'm trying to sort out some issues on our 1999 4.6L E-150. A few problems are related to the drive belt. It was replaced within the past year or so, but is now squeaking. Unfortunately, I thought I could fix the problem by spraying some belt dressing on the belt, but it only made the noise louder and more constant! Additionally, the AC has never worked for us, but when you turn the **** to AC, it makes the engine surge intermittently. Taking a look at the belt while its running with the AC on, I can see the AC pulley spin a bit, give up, then spin again. My theory is that when the AC tries to kick on unsuccessfully, the engine has to work harder to drive the broken compressor, and surges as a result. Is there anything to this theory? I also thought the broken compressor could be causing additional friction on the belt, and may have caused it to glaze over and harden, making the squealing noise. Is this possible? could it have ruined the belt so quickly?

The belt diagram on the radiator bracket shows an alternative routing for engines without the AC pump. Does this mean I can remove the AC unit altogether and install a new belt? can I use the same tensioner? will I need a different length belt?

Thanks in advance for taking the time to think about this with me!

-RJP

Also - I am looking to replace the lowermost shroud covering the radiator fan area. Not the one directly around the fan, but the one clipped to that one spanning the gap to the frame. What the heck is it called? Cant seem to find it anywhere!

 

From what you describe it sounds like the AC system is low on refrigerant (R134).
After confirming that , you might just replace the belt and as you now know , belt dressing is a band aid and doesn't help. Make sure the belt tensioner is functioning and free to do its job.