I have replaced my injectors about 4,000 miles ago. Since then the last couple of months i am noticing what I call a Octane ping or knock. But it only happens when the engine is at operating temperature and if i am lightly in the throttle, as soon as i get into the throttle it goes away. i took it back to teh dealer that installed and injectors and they said they couldnt find anything wrong and they couldnt hear anything. I took the truck back again and had the mechanic ride with me and when i noticed it he said it was the injector timing and that was normal from 03 on. Can anyone here confirm that? They were also asking why my exhaust tip and rear fender was so black with soot. Said don't know was hoping they could tell me but they are seeing no problems since the injectors were changed. Fuel mileage pulling a 5,000lb enclosed car trailer is still only at 10 or so if i am lucky. There is an Edge programmer and it does make the ping noise no matter what stage, typically i am in Level 1. I also have noticed that it has been quieter with a fuel additive that they sell (cant remember the name) and i would typically buy the fuel additive from Fleet Farm. On this last fuel tank i filled up at a different fuel station wondering if I was getting crappy fuel so only time will tell.

Any advice would be great.

 

I only buy my fuel from Mills Fleet Farm as its some of the best diesel sold in my area, btw I've never had bad batch of fuel from them here in IA. As for additives Howe's or Power Service in the white jug are both good additives. BTW if you want to use a programmer ditch the Edge and buy a Smarty.