HPOP rattle

[OLDBULL8]

I've got a rattle some place in the engine compartment. Sounds like it's coming from the HPOP. Coming back from Wyoming I heard a slight squeel then along the way I'd get the rattle noise while idleing and it will disappear when accelerating, but noise when cruising. Truck runs good, oil up to par. Thought at first it was the TC going out, but no slip there. No CEL on. This started soon after an oil change, changed it myself, Delo 15-40. Any idea.

 

[foxman]

Check the idler pulley s. You can buy just the bearing and replace without replacing the wgole pulley.
Foxman

 

[h2odrx]

that is what it sounds like to me, mine went in the same way.....

 

[OLDBULL8]

Thats what I'm thinking now also as I was getting some squeal and rattle.

Re-searching the HPOP it can have the same symtoms, squeal and rattle from cavitation, just found out there is a screen in there. Just ran an engine cleaner a short time ago (Auto-RX) may have partially plugged that screen, gotta check that also.

Thanks guys.

 

[Mutley]

I just went thru all that nonsense. Did the water pump and the upper pulley only to have the tensioned pulley fail. I'm getting the sense that it's best to replace entire groups of things on these trucks when the time comes. That tensioner sure did squeal like a scalded pig before it failed/seized.