Been looking for answers on existing threads, but nobody seems to be having the same issue I am. First a little background I have a 2008 PreRunner TRD Off Road, it has 40K (mostly babied) miles on it, I have added a TRD CAI and TRD Cat back.
In the last couple of weeks I have noticed a strange sound from what appears to be the engine. The best way to describe it is a cross between a tap and creaking sound. Imagine holding a piece of foil taut and dropping metal ball bearings on it (sounds strange but the best way I can describe it). I have noticed it most uphill at low RPM (1000 to 1500) in that between gears area - truck has shifted to a higher gear before ascending up hill and hasnt shifted down yet and I havent given more gas.
I have checked for any loose parts in the engine compartment that might be creating the sound and havent found anything - any ideas?