I drive a 1994 Pickup. 22re, Manual Transmission, 2wd. 106,800 original miles.
I am the third owner, bought the car 7 months ago with 98,000 miles on the odometer.

The problem:
For a few weeks, I've been noticing a "knocking" or "clicking" sound coming from under the hood while driving. The sound is not constant, it varies depending on RPMs. It generally tends to dissipate with higher RPMs and come back with lower RPMs. I rarely hear the noise while idling. While in 5th gear and cruising at 55 or 60 mph I do not hear the noise. It's a medium pitched noise, not very sharp, almost sputtery. There seems to be no change in the way the car drives, no loss of power, no change in fuel economy.

Any ideas as to what the sound may be? Should I be concerned?

I am new to YotaTech and also a new owner of an older model pickup. Anything I should look out for as the odometer ticks up? Any maintenance tips? Doing my best to learn about the truck and take care of it.

Thanks.