Clankety-clank only uphill?

[HRTKD]

While idling (at at higher RPM's) I hear a clankety-clank from the bottom of the engine around the oil pan - maybe a little forward of the pan. But only when parked facing uphill. On a level surface or even pointing downhill the sound goes away. It sort of sounds like ball bearings are stuck in the fan shroud and keep getting tossed around by the fan. But the noise definitely isn't coming from that area.

Most of the heat shields have been removed so that isn't it. It really sounds like it is coming from the inside of the engine. If I increase the RPM's the sound increases in frequency but not nearly as much as I thought it would.

 

[exotic_4x4]

Valve chatter..my old Dakota did it. took it to dodge told them the advance the timing took care of it..OR a sign of. Bad injector they tend to start knocking when they go bad I bet its your timing tho, not really a big issue I wouldnt mess with it if its not to loud

 

[HRTKD]

The valves would make different noise depending on the angle of the truck? Wouldn't valve noise be more prominent at the top of the engine than the bottom?

 

[hondaxr650]

Could be the starter drive gear bouncing off of the ring gear if you have something coming apart in your starter. The angle of the truck could affect it. Ive seen quite a few Ford starters with the solenoid bolts falling out of them.

 

[HRTKD]

Hmm, the starter is less than 2 years old. But I'll take a look at that.