Hey all,

I been searching threads and trying to come up with some conclusions, but only have one vehicle right now and not sure if I should drive to the dealer of have them flat bed it in....

STOCK - 2004.5 LLY CC 2500HD 21k miles. nearly all highway and only approx 5k towing 2k-9k loads.. No exhaust, Edge, ETC.


Symptoms:

starting last night I heard several knocks on de-acceleration. This was all around 60mph. when I noticed my first set of knocks, I would accel by having the tranny drop down a gear, then let off the accerator. I heard 3-4 knocks with mild hesitation. I use good quality diesel, well at least at busy stations. I have approx 3/8 tank. I was no hauling a load.

Today, I was pulling my bass boat, and near my house with traveling a slight grade at 30 mph, it started spitting and sputtering, and had large amounts of black and white smoke. It got worse if I accel'd. I drove it about 2 miles at 30MPH and parked it in my driveway. I did not notice oil level/pressure or temp issues, as I was too busy looking at the smoke!!! I have noticed lately that the truck is not as responsive, and burn more diesel. So far, there is no service lights ro anything illuminated.

Question:

Should I try to get it into the dealer, or will I be calling a taxi to pick me up half way there. Any catch phases to respond to the stealer if I get the run around. If this is an injector issue, any TSB to get them all replaced, or is it still the LB7 only who get full replacements?

Any help would be appreciated.

Sounds like injectors... on stock LLY... hmm

Almost identical to the symptoms on mine, towing the boat also..... had 2 bad injectors. Take it in to the dealer, the knocking and white smoke will have them looking at injectors to start with.

towing is covered by the factory warrenty if you have and edge system on it take it off as they can void your warrenty over it. the probleem is bad injector leaking into the cylinder and causing noise and smoke

Same here, I got the "fuel ecm is bad and needs replacing". We traded in a 20k mile truck because we cannot wait to find out what is actually wrong. Business is good and we cannot afford to sit by while GMC tries to fix it. Hope you have better luck then we do here in Alabama with dealer fixes. These trucks are good when they are running, but terrible when you have an issue like this.

Bailey, don't know where you are in regards to auburn, but Dyea chevrolet kicks butt. They could probably help you out. Don't know if they'd touch a GMC but it's worth a shot, they are good people in my book.

if you wait it will get worse and the the truck wont be able to go over 20mph like mine
it sitting at the dealer now had to have it towed casue 20mph on the 101 is alittle slow had it towed

I'd drive it in. **** if it breaks down call them and make them come get you. My truck did the same exact thing, minus the boat. I'd hit about 1500 rpms in 5th gear seemed to be around 50 mph and it did it the most on a slight incline, but she would sputter and miss and smoke like nobodys business.

Make sure you tell the stealer to check your balance rates. the first time my truck went in of course they said they couldn't find anything. After I kept screaming injectors and asked to see the print out of the balance rates they finally "Noticed" that 1 injector was dead and another was "Really Low" on the balance rates.

Also be prepaired to wait a few days to get the injectors. I took my truck in on a thursday and they didn't get the injector in until the following wednesday, but it only took them a few hours to fix it.