LBZ loud knock undiagnosed - Chevy and GMC Duramax Diesel Forum
06-07 LBZ & LLY Duramax Powertrain Discussion of components that are directly involved in the power production and all that is needed to get and keep the truck moving . Engine , Transmission, Etc.

 5Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 20 (permalink) Old 09-01-2019, 07:50 PM Thread Starter
Junior Member
 
topshelfproducts's Avatar
 
Join Date: Jul 2016
Posts: 77
Garage
LBZ loud knock undiagnosed

Finally took delivery from a private party on my new to me 06 lbz. I have had a lot of duramaxes over the years and a few lbz's and have really enjoyed them. I was so excited to pick up this truck as my old man tow pig as I planned on keeping forever. The truck came from a diesel mechanic who seems very reputable, and who I am still giving the benefit of the doubt too.

Truck was delivered 5 hours across Montana to me this morning. I paid and drove the truck for a bit and it seemed very solid all around, after 5 minutes I came home and noticed kind of a loud thumping sound. I turned it off and looked through everything and tightened everything and seemed to go away on next startup. Took a drive after a while with the wife and 5 minutes in I shut it down and put on a tow truck after checking everything as it sounds like its coming apart. Beyond bummed obviously. Anyone have any ideas? Currently at my trusted shop till next week when they can get to it I hope.

Attached Images
File Type: jpg IMG_20190901_173654.jpg (66.5 KB, 93 views)

06 lbz; No zone trans with ppe triple; delipped cut coated lb7 pistons, lbz rods;Keyed crank and cam, oil pump; Arp main studs, head bolts, rod bolts, flex plate bolts; air dog 165; stock cp3 with new fpr, 30 overs; PPE Mani and ups
profab y bridge and coldside; banks hotside; dk heads; half of my 401k...
topshelfproducts is offline  
Sponsored Links
Advertisement
 
post #2 of 20 (permalink) Old 09-01-2019, 08:16 PM
Junior Member
 
Join Date: Oct 2016
Location: logan, UT
Posts: 246
Sounds like it could be an exhaust leak.

2005 Silverado 2500, Crew Cab Short Bed. 122,000 miles
MODS: AFE intake, LBZ mouth piece, MBRP cat- less exhaust.
DailyDmax is offline  
post #3 of 20 (permalink) Old 09-01-2019, 08:19 PM Thread Starter
Junior Member
 
topshelfproducts's Avatar
 
Join Date: Jul 2016
Posts: 77
Garage
Quote:
Originally Posted by DailyDmax View Post
Sounds like it could be an exhaust leak.
I sure hope something simple, but couldn't feel anything at the time. Of course we were diagnosing in a busy parking lot as well. Thanks for helping my hopes.

06 lbz; No zone trans with ppe triple; delipped cut coated lb7 pistons, lbz rods;Keyed crank and cam, oil pump; Arp main studs, head bolts, rod bolts, flex plate bolts; air dog 165; stock cp3 with new fpr, 30 overs; PPE Mani and ups
profab y bridge and coldside; banks hotside; dk heads; half of my 401k...
topshelfproducts is offline  
Sponsored Links
Advertisement
 
post #4 of 20 (permalink) Old 09-01-2019, 08:25 PM
Junior Member
 
Join Date: Oct 2016
Location: logan, UT
Posts: 246
Hopefully its something not to serious. Being that it's in rythem with the motor and has a deeper sound, I would guess exhaust. Next guess would be valve train, but usually that is quicker due to being cam controlled.

2005 Silverado 2500, Crew Cab Short Bed. 122,000 miles
MODS: AFE intake, LBZ mouth piece, MBRP cat- less exhaust.
DailyDmax is offline  
post #5 of 20 (permalink) Old 09-02-2019, 03:20 AM
Duramax Forum Supporter
 
ALLY Cat's Avatar
 
Join Date: Nov 2009
Location: Indy OR 7S5
Posts: 3,058
Looks like a nice truck, did you contact the seller? Might be able to provide some clues. Check the usual stuff like removing the oil fill cap while it"s running to check for crankcase blowby. Any exhaust smoke while it's running?

2004.5 GMC SLT 4X4 CCLB LLY Ally, EFI Live V2 & DSP5 by Rob, trans by Mike L, Magnaflow DP, Ride Rites, LBZ turbo inlet mod, AD II 165, po' man CAI, HIDs, stock height, Cognito tie rods, Bilstein 5100s, Isspros, H2 wheels with Toyo OC 285-70-17s, B&W turnover & Companion, Prodigy P3, dog snot on windows......


Sent from my antique HP DV7-4183cl with Radeon HD5470 graphics, Beats Audio and Blu-ray drive.....
ALLY Cat is offline  
post #6 of 20 (permalink) Old 09-02-2019, 06:55 AM Thread Starter
Junior Member
 
topshelfproducts's Avatar
 
Join Date: Jul 2016
Posts: 77
Garage
Quote:
Originally Posted by ALLY Cat View Post
Looks like a nice truck, did you contact the seller? Might be able to provide some clues. Check the usual stuff like removing the oil fill cap while it"s running to check for crankcase blowby. Any exhaust smoke while it's running?
I was really excited for the truck, hopefully my next thread is just about the truck lol.

Seller was really surprised as again they had zero issues on the drive down, nor did I after my initial drive until I heard the noise and went away.

No cel, no blowby whatsoever, no exhaust smoke or hazing and seems to run clean. I may go poke around it today and see if the sound is there on a cold start as well. I am trying to round up new fuel filters to put on but not sure where else to look.

06 lbz; No zone trans with ppe triple; delipped cut coated lb7 pistons, lbz rods;Keyed crank and cam, oil pump; Arp main studs, head bolts, rod bolts, flex plate bolts; air dog 165; stock cp3 with new fpr, 30 overs; PPE Mani and ups
profab y bridge and coldside; banks hotside; dk heads; half of my 401k...
topshelfproducts is offline  
post #7 of 20 (permalink) Old 09-02-2019, 10:08 AM
LHN...We ARE the Joneses
 
Hook'em_Horns!'s Avatar
 
Join Date: May 2008
Location: Awww-stin, TX
Posts: 25,196
Send a message via Yahoo to Hook'em_Horns! Send a message via Skype™ to Hook'em_Horns!
?
Any change in oil pressure?
Any codes? (no CEL, but there could be codes)
Rod knock is louder.
Injector knock usually isn't that loud, but I've never heard failing 60 overs.
In between.

Phone picks up everything, can you isolate? Front rear left right upper lower...
Manifold leak either is or isn't, doesn't come & go.
topshelfproducts likes this.

2007 LBZ 3500 LT3 DRW Crew Cab, Sulastics, Putnam XDR 15K, B&W 30K-Turnover GN+Companion, Ride-Rite Air...EFI'd by Rob
2008 LMM 3500WT DRW Crew Cab, 8 'Flat/GN, Workforce Alum Toolbox, Ride-Rite Air

Use-ta Haves 2006-6.0 3500 WT DRW ExCab Flatbed, 2005-LLY 3500 LS DRW Crew Cab, 2002-LB7 3500 LS DRW Crew Cab
I Live my life in such a way that when my feet hit the floor in the morning...Satan shudders & says "Oh shit, he's awake!"
Hook'em_Horns! is online now  
post #8 of 20 (permalink) Old 09-02-2019, 11:10 AM Thread Starter
Junior Member
 
topshelfproducts's Avatar
 
Join Date: Jul 2016
Posts: 77
Garage
Quote:
Originally Posted by Hook'em_Horns! View Post
?
Any change in oil pressure?
Any codes? (no CEL, but there could be codes)
Rod knock is louder.
Injector knock usually isn't that loud, but I've never heard failing 60 overs.
In between.

Phone picks up everything, can you isolate? Front rear left right upper lower...
Manifold leak either is or isn't, doesn't come & go.
Oil pressure holds steady as it should. Started again this morning and same sound so shut it off immediately. I don't have a code scanner unfortunately available, may borrow one and go check this afternoon however.

To me it seems to be coming from the front passenger side, I can't seem to isolate well as the sound is loud and echoes through the engine bay. I can seem to feel it pulsing with the knock in the cold side boot slightly and the intake slightly it seems.

Hurry up and wait kind of situation, hopefully my mechanic can get to it this week but he has been really busy lately. I checked everything again this morning and don't see anything loose etc anywhere, no leaks.

Appreciate all ideas, I figure worst case once it gets solved I can add solution and it can be search material if others encounter a similar issue.

06 lbz; No zone trans with ppe triple; delipped cut coated lb7 pistons, lbz rods;Keyed crank and cam, oil pump; Arp main studs, head bolts, rod bolts, flex plate bolts; air dog 165; stock cp3 with new fpr, 30 overs; PPE Mani and ups
profab y bridge and coldside; banks hotside; dk heads; half of my 401k...
topshelfproducts is offline  
post #9 of 20 (permalink) Old 09-02-2019, 11:40 AM
DuramaxForum Enthusiast
 
BAMAWHISTLER's Avatar
 
Join Date: Mar 2013
Location: Alabama, Roll Tide!!!
Posts: 2,754
Nice lookin truck from the pic. How many miles on the truck, and how many on the engine? Any warranty left on the build?

2006 LBZ 2500 CCSB 2WD
EFI LIVE, DSP5, Edge CTS & EGT probe, PPE airbox mod, AFE hotside pipe, PPE manifolds/uppipes, MBRP DP, MBRP 4" side dumped, Sinister coldside pipe, pcv reroute, Beans sump, Kennedy lift pump, dual filters, coolant bypass filtration, Nuc Motorsports Oil Bypass kit, LML 20s & 265/60R20s, tint, LEDS, some chrome
ALABAMA LBZ Build Thread
BAMAWHISTLER is offline  
post #10 of 20 (permalink) Old 09-02-2019, 11:45 AM Thread Starter
Junior Member
 
topshelfproducts's Avatar
 
Join Date: Jul 2016
Posts: 77
Garage
Quote:
Originally Posted by BAMAWHISTLER View Post
Nice lookin truck from the pic. How many miles on the truck, and how many on the engine? Any warranty left on the build?
Truck has 155k, 8k on motor build and transmission build. No warranty unfortunately as previous owner who is a diesel mechanic built it himself.

06 lbz; No zone trans with ppe triple; delipped cut coated lb7 pistons, lbz rods;Keyed crank and cam, oil pump; Arp main studs, head bolts, rod bolts, flex plate bolts; air dog 165; stock cp3 with new fpr, 30 overs; PPE Mani and ups
profab y bridge and coldside; banks hotside; dk heads; half of my 401k...
topshelfproducts is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Chevy and GMC Duramax Diesel Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome