Clicking Noise

[futon]

Rhythmic clicking noise. Easy to hear in the cab. Does not sound like marbles in a can or buzzing.

Three reliable ways to reproduce the sound:

• In neutral, while stopped, carefully hold RPM around 1100. Sound starts at ~ 1000 and stops around 1200. Regular clicking, but subtle.
• While driving normally or accelerating firmly from a start, sound starts between 2000-3000 RPM and gets much louder, but not faster. The sound competes/mixes with the exhaust note. It's not drowned out, and my exhaust is loud.
• On the highway, around 65 MPH in fifth gear, sound starts when I ease off the throttle slightly. Goes away with increased throttle pressure (even though RPM not changing appreciably). Heard clearly over the road noise.

Some notes:

• Custom 3" exhaust.
• Flex pipe on the driver side, but I don't see any on the passenger side.
• No heat shields, but good clearance, including around cross member.
• Transmission mount in good condition.
• No witness marks I can see on or around the exhaust.
• No changes when clutch disengaged.
• Sound seems loudest at the oil pan.
• Truck has a poorly installed Hurst shifter with a gap at the boot, so I tend to get lots of transmission and engine noise in the cab.

Only had the truck for about a month. No idea how long it's been like this.

 

[Curious Hound]

I'd be looking for an exhaust leak.

 

[RangerNumber3]

Maybe the heat shield on the catalytic converter?

 

[Curious Hound]

Make sure you don't have any "friends" nearby when you're listening for the noise.

 

[futon]

Maybe the heat shield on the catalytic converter?

No heat shield (at all)

 

[futon]

I'd be looking for an exhaust leak.

Plug the tail pipe(s) and listen for whistling?

I posted a short video here:

https://www.reddit.com/r/fordranger/comments/1slor5c/rattle_at_certain_rpms

 

[futon]

I'm starting to think this is my real problem.

Covered this up with a heavy towel, went for a drive, and OMG. Nearly all the road noise, clicking, and whirring goes away. I think if I had a properly installed lower boot, and a factory shifter, I'd have no idea the clicking was even there.