Took the serpentine belt off the new-to-me 2003 2.4L to run the engine momentarily without the serpentine belt. Trying to run-down the cause of a squealing noise. Pretty positive now it's the water pump. Anyway, when I was putting it back together, I looked up the routing of the belt since those things always cause me so much grief trying to remember how they went on. I quickly noticed that the routing shown wasn't possible on my engine. Upon further review, a PO at some point swapped one of the idler pulleys to an incorrect location and came up with a new, creative route for the serpentine belt. The main downside is that their route ran the grooved side of the belt across the flat side of one idler pulley, but based on the actual groove wear/belt deposits on the pulley face, they ran it that way for many thousands of miles (maybe well over 100,000 since the engine is up to 240,000). I swapped the pulley back to the correct location and the belt still fits just fine. So odd that Jeep installed a threaded bolt hole there that would actually allow the idler pulley to be placed in an incorrect location. I have no idea what the purpose of that threaded hole might actually be for. Pictures below to show how it was done!
The wrong way. The idler pulley in the top left isn't where it belongs.
And the correct idler and belt position.
The wrong way. The idler pulley in the top left isn't where it belongs.
And the correct idler and belt position.
