2007 Ford F-150 • V8 4WD Automatic • 74,000 miles

About three days ago I was pulling my trailer through the west virginia mountains, when I heard a noise which sounded like my trailer chains dragging on the ground but it was coming from the drivers side of the engine. It only happened when I was accellerating up a hill or when I would hit the gas. When I would let off the gas pedal the noise would stop. I kinda check the pulley assembly for some looseness but I didnt dig into it really far, but it seemed fine. Any recommandations?
Thanks for your time
March 16, 2011.

Engine ping perhaps?

Mar 16, 2011.
Try using higher octane gas to see if this broken bottle sound goes away. Do you have a check engine light on? May have a knock sensor code. If the knock sensor is out in this engine, you will have knocking/pinging noise as ECM cannot detect knock/ping and correct timing, which is ECM adjusted only.

Mar 16, 2011.
A sound like trailer chains dragging. Check the heat shields on the exhaust system for loose or missing tack welds. Fords are notorious for this and have been since the inception of catalytic converters.

Check the timing. Make sure it's set right and advancing properly under acceleration/load.

How regular is the sound? Does it sound rhythmic or is it random?

Jun 15, 2011.