Newbie rescues an LB7

[Delta.Speed]

Hello all!

I put together my intro post and now hopping right into the action.

My truck is an 02 2500HD CC LB 4x4 that I recently acquired in poor mechanical condition for dirt cheap.

Ive dived right in to address the first set of issues.

My biggest concern with the truck is some tapping that could be heard coming from the intake box. The truck runs fine and has no engine codes other than a code for a deleted IAH that hasn't been tuned out.

Since I'm new to diesels, I took it to a professional diesel shop for a diag and their thoughts on the sound. They threw some likely culprits my way but said they couldn't be sure without some tear down.

According to them, I am most likely looking for either a bent valve or pushrod, a lifted injector cup, or improperly set valve lash.

So I've started tear down on the truck to look for the source of the tapping. I've already found some pretty questionable practices on it, like a siliconed coolant pipe, very sloppy wiring work for the aftermarket headlights, and some underbody lights that are taped to the ebrake cable....smh...

Im going to be focusing strictly on the engine first though.

I'm working with LDS and Calibrated Power mostly for my parts and tuning needs.

So far, I've purchased 45% SAC injectors from LDS to replace while I'm in there, and I purchased a switch on the fly tune from Calibrated Power.

I've got a pretty solid parts list put together for stuff that I intend to replace while I'm in there taking the heads off to go to a machine shop.

I'll post the parts list on a post here so I can get some of y'all thoughts on it.

Sent from my SM-S908U1 using Tapatalk

 

[Delta.Speed]

Here's my current parts list from LDS diesel. I'm waiting to pin point the issue before putting the order in. As I mentioned above I already have the 45 SAC injectors, and the tune to make all this work is also on the way.

I've also purchased a turbo elbow that was recommended by calibrated power, and have plans to purchase a FASS 165 as soon as I've got the engine all up and running.

If some of you veterans that have done this a few times could take a look over this parts list and give me some insight on what I may be missing it would be much appreciated.

Im trying to get the truck fixed right the first time to enjoy some reliability down the line.

Currently I have no increased power goals. Any additional power that comes out of this is just a bonus to me. I want a solid truck first and more power later.

Sent from my SM-S908U1 using Tapatalk

 

[2004LB7]

why are you replacing so many lines? the only lines that need replacing if you don't want to clean up the old ones are the high pressure injector lines. all the others, including the return are reusable. any rubber lines can be gotten from your local auto store for cheap. the banjo bolds that you are replacing only need to be replaced if you messed up the head or hex socket. otherwise it's the copper crush washer that is supposed to be replaced not the bolt.

LDS can, and normally does ship all the copper crush washers that will be needed for the injector replacement

and before pulling the heads, unless you know you have a blown head gasket, pull the valve covers and inspect the top end. it very well could be something as simple as valve lash

no need to a CP3 kit either unless you really want to. just replace the rubber hoses.

you have a lot of stuff on there that to me is just wasting money that could go to fixing up other areas of the truck. in my opinion, stick to the known issues first then do any upgrades next. that way you don't possibly introduce too many variables that can make someone new like you pull your hair out trying to figure out what went wrong

 

[down_hiller]

I agree with 2004LB7 when I tore mine apart none of the bolts were that hard to get out. I just made sure to clean them out good and tap the allen socket in with a hammer lightly. None of them rounded. When/if you replace the CP3 I learned the hard way to make sure you use a torque wrench to put the gear back on. I put mine on too tight and it cracked the gear.

Nice truck btw

 

[KyleC4]

As stated, figure out the noise first while the truck is still together. Pin point to most likely source then tear down. Grab a stethoscope and probe around. Depending on what you find it could cost you very little, or a lot.

 

[TheBac]

If previous owner tore it down and was a poor mechanic like you think, its probably incorrect valve lash. Been a while, wasnt proper supposed to be .011-.012?

If it were a lifted cup, you'd be pressurizing the cooling system, and/or have a coolant use problem similar to headgaskets.
If it were a bent pushrod or bad valve, engine would run rough or not at all

That parts list could be pared way back. As the guys have stated, do the proper diagnostics first to narrow it down.

 

[Bdsankey]

Not to jump on the same bandwagon but I would 100% nail down where it's coming from before throwing your wallet at it. My first thing would be check/set valve lash, put the lines back on, and see if the noise is gone.

 

[Delta.Speed]

why are you replacing so many lines? the only lines that need replacing if you don't want to clean up the old ones are the high pressure injector lines. all the others, including the return are reusable. any rubber lines can be gotten from your local auto store for cheap. the banjo bolds that you are replacing only need to be replaced if you messed up the head or hex socket. otherwise it's the copper crush washer that is supposed to be replaced not the bolt.

LDS can, and normally does ship all the copper crush washers that will be needed for the injector replacement

and before pulling the heads, unless you know you have a blown head gasket, pull the valve covers and inspect the top end. it very well could be something as simple as valve lash

no need to a CP3 kit either unless you really want to. just replace the rubber hoses.

you have a lot of stuff on there that to me is just wasting money that could go to fixing up other areas of the truck. in my opinion, stick to the known issues first then do any upgrades next. that way you don't possibly introduce too many variables that can make someone new like you pull your hair out trying to figure out what went wrong

Thanks for the info on the lines. Ill pull back on the lines except for the ones you noted. Regarding the rubber hoses, as a personal preference I like prebent rubber hoses vs buying generic hoses and bending them as I've found that sometimes when they get hot and soft they are prone to kinking in tight bends.

I am going down to the head gaskets to replace them and stud the heads because I do have cooling system pressurization, and black deposits on the bottom of the coolant tank. The truck drove 200+ miles home at 85mph without overheating, but when I unscrewed the cap of the reservoir coolant came gushing out big time.

Since I'm already so deep into it I want to take the heads to a machine shop for a valve job and to have them inspected for cracks.

I have never set valve lash before so I'm going to follow the step by step in the repair manual I bought.

Sent from my SM-S908U1 using Tapatalk

 

[Delta.Speed]

I agree with 2004LB7 when I tore mine apart none of the bolts were that hard to get out. I just made sure to clean them out good and tap the allen socket in with a hammer lightly. None of them rounded. When/if you replace the CP3 I learned the hard way to make sure you use a torque wrench to put the gear back on. I put mine on too tight and it cracked the gear.

Nice truck btw

Thanks for the torque wrench tip, learned that the hard way several years ago while camming my sierra. I torque everything that has a spec to spec now.

Sent from my SM-S908U1 using Tapatalk

 

[Delta.Speed]

If previous owner tore it down and was a poor mechanic like you think, its probably incorrect valve lash. Been a while, wasnt proper supposed to be .011-.012?

If it were a lifted cup, you'd be pressurizing the cooling system, and/or have a coolant use problem similar to headgaskets.
If it were a bent pushrod or bad valve, engine would run rough or not at all

That parts list could be pared way back. As the guys have stated, do the proper diagnostics first to narrow it down.

So I do have cooling system pressurization and I also have soot deposits on the bottom of the reservoir.

I haven't ruled out an injector cup as a possible culprit of the noise because I have the headgasket like symptoms.

Im thinking since I'm going to have the heads off already I'll have the machine shop thread the injector cup opening to go with these screwed on injector cups for good measure.

Any thoughts on them??

Sent from my SM-S908U1 using Tapatalk

 

[Delta.Speed]

More traces of shit mechanic..... yes that's a 13mm socket sitting under the valve covers.... no its not mine I dont own snap on stuff....

 

[Delta.Speed]

So update for you guys that are helping me on my first venture into one of these engines. Got one of the valve covers off, and definitely going to be checking valve lash. From working on gas engines I think I have a general idea of how much valve lash is too much, and without setting the engine to any specific position there are several rocker arms that I can wiggle with my hands and they'll rock a solid 2-3 mm.... haven't positioned the engine to check for specs yet, but to me that much movement seeems excessive.

If I'm able to verify bad valve lash with specs I'd be psyched because it would mean I might have found the source of the noise.

Still gonna go in and take the heads off because as I mentioned above I do have headgasket symptoms and I'd rather be safe than have to go back in and do all this again.

I do have a question for you guys though.... if this was the first time I was tearing up one of my LS, sbc, or bbc engines, I'd DEFINITELY be replacing lifters for some high performance ones while I'm there because sbc, bbc, and ls lifters are known to go bac at higher mileage.

So considering the truck has 217,000 and I'd rather not have to tear this deep into it again for a while, is it a good idea to replace the lifters while I'm here?

Sent from my SM-S908U1 using Tapatalk

 

[2004LB7]

Valve lash instructions here. https://www.duramaxdiesels.com/forum/attachments/valveadjustment-pdf.106842/

Duramax's are not known for bad lifters. I'd only replace them if you know they are bad and there is nothing wrong with using stock lifters again

was the rubber coolant line still hard after the engine cooled off?

 

[Delta.Speed]

Valve lash instructions here. https://www.duramaxdiesels.com/forum/attachments/valveadjustment-pdf.106842/

Duramax's are not known for bad lifters. I'd only replace them if you know they are bad and there is nothing wrong with using stock lifters again

was the rubber coolant line still hard after the engine cooled off?

Yes, the upper hose was very hard even the next morning. Also, while the truck was running I could hear gurgling and bubbling inside the reservoir.

Sent from my SM-S908U1 using Tapatalk

 

[Delta.Speed]

If previous owner tore it down and was a poor mechanic like you think, its probably incorrect valve lash. Been a while, wasnt proper supposed to be .011-.012?

If it were a lifted cup, you'd be pressurizing the cooling system, and/or have a coolant use problem similar to headgaskets.
If it were a bent pushrod or bad valve, engine would run rough or not at all

That parts list could be pared way back. As the guys have stated, do the proper diagnostics first to narrow it down.

Hey so I followed your advise and checked the valve lash before taking the engine apart and what I found makes me think the noise isn't valve lash.

I found the valve lash measurements to be all over the place. I highly doubt whoever was in this engine before me followed any kind of procedure at all. I had some valves come in at over .030 on the feeler gauge and then I had others that were supposed to be free and were still pressed. So I'm pretty sure valve lash was not properly set on this truck at all.

The truck has very poor acceleration as one of the symptoms and I'm thinking that maybe some of these valves not closing all the way could be a culprit for that. But with so many valves out of spec I dont think my noise is coming from valve lash because I only hear a single rhythmic tap for about every engine rpm. I dont think it sounds like 4+ valves are loose.

This combines with my cooling system pressurization, soot deposits in the overflow tank, and gurgling/bubbling in the tank makes me think that my issue could be an injector cup.

So I think I will go ahead and remove the heads and re-assemble everything correctly and see if my noise is gone.

Thoughts?

Sent from my SM-S908U1 using Tapatalk

 

[TheBac]

Are you sure you were checking every cylinder at TDC? Dmax cylinder numbering is different than GM past practice. Id recheck.

 

[Delta.Speed]

Are you sure you were checking every cylinder at TDC? Dmax cylinder numbering is different than GM past practice. Id recheck.

I was following this:

Sent from my SM-S908U1 using Tapatalk

 

[TheBac]

Yup, thats right. Sounds like someone did a very poor job on the valves, too.

 

[Delta.Speed]

Yup, thats right. Sounds like someone did a very poor job on the valves, too.

I think I just discovered the root of all my evils.... there are 7 injectors that look like the one on the left..... the one on the right is my number 1 injector..... its the closest injector to the intake box, which is exactly where the tapping noise I was hearing was the loudest.

From what little I've learn over the past month about these trucks I'm thinking this is a tattle tale sign of a bad injector cup.

Sent from my SM-S908U1 using Tapatalk

 

[DuramaxRamRod]

Missing copper washer?