[boyce]

truck has 2000 miles and has been great but today im on the interstate with cruise at 78 and hear what sounded like another diesel but it was me. i pressed the throttle and it felt like i cut out and sputtered for about a second with a decent size cloud of grey and black smoke comming out of the exaust then it cleaned up and quited down. then it happened again in the next 10 or so miles. engine temp was about 180-190 oil press was 60 and trans 150. i pulled over and nothing seemed out of the ordinary and it ran fine the rest of the way ( about another 30 miles). it seemed like my 2 stroke outboard does when it runs at low rpms for a while and loads up then i get on it and it smokes and sputters for a bit till it cleans up. sorry this was so long just to ask why?

 

[DMAXSHAWN]

maybe you got some dirty fuel (you know these trucks seem to have a great filtration system) check your fuel filter may have water in system with grey smoke.

Shawn

 

[boyce]

thanks. ive only filled up at big truck stops like all on here say is best to do. do i need to take the filter off to check or does it have a pitcok valve?

 

[04llygmc]

There is a valve on the bottom of the filter

 

[DIESELMAN75]

this sputttering surging thing seems like it is happening to a few people on this site i wonder what the real problem is because a bad load of fuel you would think would affect the truck the whole time tell you got new fuel because i dont think it can be bad fuel for just a few sec and then it is good fuel and it is running good again

 

[bobo]

truck has 2000 miles and has been great but today im on the interstate with cruise at 78 and hear what sounded like another diesel but it was me. i pressed the throttle and it felt like i cut out and sputtered for about a second with a decent size cloud of grey and black smoke comming out of the exaust then it cleaned up and quited down. then it happened again in the next 10 or so miles. engine temp was about 180-190 oil press was 60 and trans 150. i pulled over and nothing seemed out of the ordinary and it ran fine the rest of the way ( about another 30 miles). it seemed like my 2 stroke outboard does when it runs at low rpms for a while and loads up then i get on it and it smokes and sputters for a bit till it cleans up. sorry this was so long just to ask why?

This could be the EGR "poping" that the 04.5 and 05 LLY's have had trouble with. Just a bone I thought I'd throw out there. I know you have an 06, but it sounded similar.

 

[bobo]

It is a good idea to change the Fuel Filter after 1000 miles on the new motor.

 

[RoadRunnerTR21]

Mine did the same thing while driving home from a flight last November. Once it was done "pooping", it was fine. My fuel filter had been changed the month before and it had been running fine on that load of fuel. It was either condensation related or the EGR self cleaning itself.

 

[DIESELMAN75]

RoadRunnerTR21 how long did your truck sit while you were out of town

 

[boyce]

thanks for the replies, went and got new fuel, oil and trans filter today figure ill get all three since alot of you guys recomend it at around 1000.

 

[Rob147]

Could you have been just at the point where the pilot injection cuts out? If so, try driving just above or below 78 mph when you have the cruise control set. If you accelerate slowly through the pilot injection setpoint you will usually hear the noise you described.

2004.5 2500HD LLY/A CC SB

 

[Hotrodstan55]

Rob, do you mean pilot ejection?

 

[Rob147]

Rob, do you mean pilot ejection?

No (LOL), This is what I mean:

Pilot Injection​

• <LI type=disc>The sophistication and technology of the direct injection system components make the Duramax engine capable of employing a process known as "pilot injection."
  
  <LI type=disc>Pilot injection involves injecting a small amount of fuel into the cylinder prior to the main injection event. A complex process in the electronic controls selects the optimal time, duration and quantity of pilot injection, coupled with the main injection charges.
  
• The result — combustion starts on a smaller scale and builds subtly, but rapidly, for reduced noise/knock, less vibration and quieter and smoother warm-ups.

 

[banshee42096]

had my 04.5 lly d/a 4x4 cc just over a year and 32000miles have had this
happen to me 3 differant times.and it always happens when fuel was just
about at empty and alway above 72-75mph drop below that speed and
nothing. my guess is that bad fuel and when the tank gets low its sucking
the crap in faster than the filter can absorb it at that speed just my guess. never had it happen when tank is full.but when it did happen
it looked like you burnt a qt of oil there is that much smoke no problems
now.i heard just the opposite about going to truck stops for fuel i was told
that the big rigs basicly run on anything so the fuel is of bad quality?
just my 2 cents thanks

 

[h8nopi]

While your playing around with your new truck you may want to go ahead and change front and rear diff fluids. I did mine at 1000 rear was a little low and front was yellow. BTW buy an extra quart(not to expensive at anywhere besides dealer) I had to wait for the wife to get home to go get extra

 

[RoadRunnerTR21]

RoadRunnerTR21 how long did your truck sit while you were out of town

Sorry I haven't responded sooner......I'm on the road again.

My truck sat from Sunday morning to Friday night. I had just under 1/4 tank of fuel. Now I make sure that I have a 1/2 tank or better when I park it at the airport.