I recently replaced a 2011 LML in a 2500hd with a 2012 LML out of a Cab & Chasis. After the shop getting it in a running, I went to pick it up. When I took it for a test drive I noticed a slight knock. I had the shop check it and they verified that there is a slight knock in the low end. It is slight to the point that most think it is just a normal diesel sound, but since it sounds the same as the start of the problem of the one that blew I can hear it. Is it possible that the 2011 ECU could cause the knock in the 2012 motor? The ECU was deleted and tuned prior to me purchasing the truck so I don't know what type of file they flashed, but the shop said it was putting out about 50 boost and suggested having it defaulted to OEM. Once that was done it is throwing the codes for the missing sensors, so now I have purchased a tuner to remove them and get it out of limp mode.
Any idea what might be causing the knock and a way to fix it? Any help would be appreciated since I am out almost $16,000 and still have no truck.
Any idea what might be causing the knock and a way to fix it? Any help would be appreciated since I am out almost $16,000 and still have no truck.