Under load my truck makes a tapping/knocking sound at 1800 to 2000 RPMs. The load could be no more than going up a hill and the noise is still present. If the engine was a gasser I would swear that I had a lifter going.


I've changed fuel filters, fuel stations, with and without additives and it makes no difference. It does seem to be worse when the outside temps are hot.


Just a note, my fuel mileage has not dropped at all (20+) and the engine feels as strong as ever!


Any suggestiions?


Thanks,


MaxRockEdited by: MaxRock

Well i have this same issue. I could even hear it when i let off the gas and the engine was winding down. Got really loud on a road trip, I told her i was going to take her in on Monday. She decided not to make the noise for awhile. Recently i have noticed it coming back. Almost like pilot injection had quit on a cylinder.

I have an appointment next week to replace the DMF and would like some pointers so I can ensure the Tech will check the injectors if that is what is causing the noise!


Thanks,


MaxRock

Any help would be greatly appreciated!!!! http://dieselplace.com/forum/smileys/Unhappy.gif


MaxRock

I have the same exact noise, under the same conditions. No other problem is there just this metal on metal tap tap tap sound that speeds up and slows down to the RPM. Anybody know what this is?

I have the same sound. 48k on the truck.

bump http://www.dieselplace.com/forum/smileys/Confused.gif

I have had the same thing since the truck was new - now has over 52k on it. I've had three different dealers check it. One gave me the bulletin on the "tick" which I also had and it was very different; one told me it was a solenoid in an injector making noise that is present in many diesel trucks but is just more audible in the dmax as it runs quieter, and; the best tech who worked on it said that he heard the noise and could make it louder or quieter by adjusting the fuel pressure with his tech2. But, he said all injectors checked out OK so there was really nothing to fix at that time. My mileage is fairly good and this thing has lots of power to tow my 10k 5'er so I just turn the radio up and try not to hear it knowing I have a 200k injector warranty from GM. It's just an annoyance to me. Interesting how many of us have this, yet it's not universal.