Hey Guys new member, great site. Picked up a 93 F250 351W C6 with 4:10's about 150K pretty clean (by Alaska Standards) truck to haul my sleds. Anyways, driving up to 45 or 50 she runs perfect, however, when she gets to 50 or above I'll be cruising and it'll rattle (ping) sounds like a powerstroke. Funny thing is when I tip into the throttle a tic it'll go away. When I let off the gas it rattles again I can hold the throttle steady at 55 rattling away, and start up a grade and the sound disappears till I crest the hill. Had a buddy run some codes, came up with 114,116 and 327 and 328. Timing reads 10* tried premium fuel, my buddy suspects the EGR system. I dont understand why it knocks only when it's NOT under load, cruising at H/way speed.. Any ideas ? Thanks William Sr.

 

Plugged or inop EGR is not working when it's supposed to?

 

114 ACT out of self test range
116 ECT out of self test range

The engine is supposed to be at operating temp when the selftest is run and if it wasn't these codes will be set so you can ignore them.

327 EVP below min voltage
328 EVP below min voltage

Both these point to a bad EGR Valve Position sensor.. the part on top of the EGR valve with the wiring harness attached. Change that part and clear the codes and you should be good.