I've search for about 2.5 hours on the net on different forums, google and youtube. I'm not expecting someone to point to exactly what my potential problem maybe, but rather some advice or educated guess as where to go next. Figured this is by far the best duramax forum for that. Here goes:
Headed to town this morning and the truck is almost fully warmed up. I pull out onto a county blacktop and give it some moderate throttle and level out at 65-68mph. I start to hear a faint injector knock. I let off the throttle and the noise goes away. Back into it and it's growing louder. I come up to a stop at an intersection and at idle she's knocking like a jack hammer and puffing black smoke like a freight train. The thing is running very rough. I pull her into a church parking lot and get stopped and the knocking goes away and the smoke is no more. No CEL and no codes. Continued on may way to town with multiple starts and stops at 4 different stores. No issues. I get home and decide to do an injector cleaning with the GM stuff and half a gallon of diesel. I did this procedure at 200k and currently at 274k. While the truck is sitting idling I try to wiggle the injector connectors to see if it will act up. No dice, runs fine. I start to listen and kinda hear a little racket from the passenger side bank, balance rate on #5 was 3.9-6.0 at 143 degree coolant temp. That is the only one out of wack. I pulled the connector on injector #5 and restarted the truck. No change in noise.
The only other thing I've noticed is in very hot weather on hard acceleration with a load, it sounds like my old LB7 when the pilot injection would cut out. Not sure if this is normal for an 2006 LLY.
Could this be a fluke or am I head for a new injector or more in short order?
Is there anything else I can do with limited diagnostic tools?
Thanks
Headed to town this morning and the truck is almost fully warmed up. I pull out onto a county blacktop and give it some moderate throttle and level out at 65-68mph. I start to hear a faint injector knock. I let off the throttle and the noise goes away. Back into it and it's growing louder. I come up to a stop at an intersection and at idle she's knocking like a jack hammer and puffing black smoke like a freight train. The thing is running very rough. I pull her into a church parking lot and get stopped and the knocking goes away and the smoke is no more. No CEL and no codes. Continued on may way to town with multiple starts and stops at 4 different stores. No issues. I get home and decide to do an injector cleaning with the GM stuff and half a gallon of diesel. I did this procedure at 200k and currently at 274k. While the truck is sitting idling I try to wiggle the injector connectors to see if it will act up. No dice, runs fine. I start to listen and kinda hear a little racket from the passenger side bank, balance rate on #5 was 3.9-6.0 at 143 degree coolant temp. That is the only one out of wack. I pulled the connector on injector #5 and restarted the truck. No change in noise.
The only other thing I've noticed is in very hot weather on hard acceleration with a load, it sounds like my old LB7 when the pilot injection would cut out. Not sure if this is normal for an 2006 LLY.
Could this be a fluke or am I head for a new injector or more in short order?
Is there anything else I can do with limited diagnostic tools?
Thanks
Last edited:
