sudden knock

[chief1956]

hi i am new here and am having probs with my 2005 lly with 71000 miles. it was fine going home- but when i got up to go to work it has a knock on the left side of engine now. started off to work this morning and it would not even run it just missed and bucked. i have had the injector wires on #2 and #7 replaced at my expense. just wondering if anybody had any takes on this. i am going to change the fuel filter again this weekend. the knock is at 1500 to about 1800 rpms and goes away when i give it fuel or slow down. i have checked all other aspects oil ect. ect. truck has always smoked a little from brand new gm said there was not a thing wrong. just one of there many lies that they tell everyone.thank god i still have a backup truck. thanks for any help.

[Kennedy]

No plug in harness boxes/chips or anything of the sort are there?

The #2 and #7 injector wires are my first suspect. Even though they have been replaced I would suggest inspecting the terminals for signs of heat and arcing. Then the main harness in the vicinity of the alternator.

I'd also suggest that you scan for codes once and see what comes up.

[chief1956]

thank you i will check as soon as i get back home thanks. well changed filter and no water or dirt. now it smokes when i give it fuel and misses as though it has a dead cylinder and blows blue out exaust bad. i hope no motor damage. any more thoughts anybody. no chips or tuners, just a boost and pyrometer guage. although gm did do a reboot from 2005 to a 2006 cause of a rough run issue some 4 years ago. #2 & #7 wires changed little over 2 years ago thank you

[DmaxMaverick]

As Kennedy said, revisit your injector harness. It's possible it/they are damaged again, or a connector is loose or making poor contact.

Also note, if the PCM detects significant misfires on one bank, it will disable the entire bank of cylinders. This will cause very rough running, smoke and numerous codes. Check your DTC's (codes) to determine which cylinders/banks may be affected, or if it's a fuel supply related issue.

[chief1956]

hi does anybody know if GM is repairing the injector line issue or is it still at our expence. just had them replaced less than 30,000 miles ago thanks

[More Power]

hi does anybody know if GM is repairing the injector line issue or is it still at our expence. just had them replaced less than 30,000 miles ago thanks

If the powertrain warranty has expired, and if your local dealer doesn't feel your pain, you'll likely be on your own. However, be sure to check the "emissions" warranty for your vehicle. The emissions warranty is different - may be longer - depends... Your local dealer service manager would know the current situation.

Jim

[chief1956]

hi just got word that my injectors are all bad or at so much percent. GM is so generous they want to pay 50% of a $5600.00 bill any help as to where or what to do or call cause this is B/S as we all know. thanks for any help at all.

[vernj4]

Check the o-ring on the fuel bleeder plug. If chipped, will knock.

[Heartbeat Hauler]

A lot of the problem with multiple injector failures in my opinion is that there are waaay too many unscrupulous "injector remanufacturers" out there that are not remanning to factory specs or are using inferior parts, or just plain crappy workmanship. I would want to know where the dealership is getting thier remans from before I would go that route.

They should be Bosch remans, and I mean injectors that bosch has remaned. ALL Duramax injectors were originally manufatured by Bosch, so a ratbastard no account aftermarket shop can "Claim" that they are Bosch remans, when what they really mean is they are original Bosch injectors that the shop has remaned to no real spec and then calls them Bosch remans. Even junk injectors will last a year, just long enough for the dealership warranty to run out.

I'm in the same boat with a couple of injectors crapping out, but around here I have been quoted $7000 for all 8 injectors and lines. :eek:

[chief1956]

hi can anybody point me in a good direction for injectors for a lly. prefer something longer lasting that stock. thanks for any help

[More Power]

hi can anybody point me in a good direction for injectors for a lly. prefer something longer lasting that stock. thanks for any help

Here are a few vendors I would trust.

www.usdieselparts.com (http://www.usdieselparts.com) (authorized Bosch reman facility)
www.kennedydiesel.com (http://www.kennedydiesel.com) (upper Midwest US)
www.bd-power.com (http://www.bd-power.com) (in BC Canada, but ship anywhere)
www.pacificp.com (http://www.pacificp.com) (California)
www.thoroughbreddiesel.com (http://www.thoroughbreddiesel.com) (Kentucky)

Jim