Hay guys, So just recently my truck started doing a pinging / knocking right around 1700-2000 rpm only while under load, 40-60% throttle, No visable smoke and runs good in the power band everywhere else... When it first started i had it on the economy tune on the PPE hot+2... Thought it wasnt getting enough fuel or something wasnt right so I bumped it up to level 3... Ran good for a while, but I didnt drive it much after i turned it up... Today i started driving it again and its still doing it... So i set it back to completely stock, and it still does it... Is this bad fuel, timing not right, or what could it be...

I took a quick video today, if you listen around the 10 second mark you can kinda hear it...
[URL="http://www.youtube.com/watch?v=QRyO5_VANKk"][COLOR=#22229c]

Any suggestions would be appreciated!

Did you fill up with bad fuel?

Mine was doing the same thing a few months ago. Drained the tank, new fuel filter, and some powerservice additive and it was back to normal.

What ever state your in check and see who sells the best fuel. In Ohio here there is no quality standards on fuel. Really, Other states have these regulations. Here in Ohio I look for BP and Sunoco diesel. There known for a bit better quality. Check it out in your state.

right on, I've always ran sunoco gold diesel thur it and im kinda pissed now cause it seems like it is bad fuel... I thru a 1/4 bootle of cetane boost in it and it seems to be running great now.... Think im gonna run the cheap fuel thru it now and see how it does...

Thanks for the replys, lets hope that was the fix...

Last time I purchased bad fuel was from Shell, The tanker truck put Super unleaded in the Diesel holding tank they ended up sending me a check for just a little over 700 dollars.

I just went through this same thing. I ran 16 oz of stanadyne in a tank of fuel and it quit doing it. That would be the first thing I would suggest you try.

right on, I've always ran sunoco gold diesel thur it and im kinda pissed now cause it seems like it is bad fuel... I thru a 1/4 bootle of cetane boost in it and it seems to be running great now.... Think im gonna run the cheap fuel thru it now and see how it does...

Thanks for the replys, lets hope that was the fix...

Man, I would not knowingly dump cheap fuel in my tank... :badidea:

I took my contaminated fuel and tossed it in my heating oil tank.The d-max didnt like it but the furnace did.

I took my contaminated fuel and tossed it in my heating oil tank.The d-max didnt like it but the furnace did.
That work's !

mine has been doing the same thing since i got it. it comes and goes from day to day. but runnin a little more power service than recommended seems to clear it up. i also used lucas injector cleaner, both seem to help

i had a knock in mine and it was a injector knock. Under hard pull it wouldn't do it, but under light to moderate throttle it would. I replaced the injector, noise is gone.

Last time I purchased bad fuel was from Shell, The tanker truck put Super unleaded in the Diesel holding tank they ended up sending me a check for just a little over 700 dollars.
Hey bud FYI, I had a customer Freightliner FL90 w/Cummins ISC that had experienced fuel contamination due to the station filling wrong tank w/gas. The truck traveled about 10 miles with the fuel until the engine ceased to run on the gas mixture. The fuel Co. paid for the tow, filters, labor and fuel exchange. However, 20K miles later, the pump and injector performance failed due to damage sustained during the fuel contamination. No money could be reimbursed from the fuel company due to the time and previous pay out.

My truck has done this on and off to, I run injector cleaner and then i am good.