not sure what it is, or even how to describe it really. kinda sounds like a sloshing, rattling sound but only when the truck is idling. any ideas? i was thinking it might be the keepers on the timing chain or something like that, is there like a distinct sound when that happens?
could be the chain has eaten thru the guides and is now eating its way through the timming cover.Pop the valve cover and look down in there
I have to agree with ^. If its only at idle, get to checking the timing chain and the guides. If your chain is currently rubbing on the timing cover, you will be in for a world of hurt when it reaches your coolant jackets.
