Finally got the truck running, help

[OleBlackyLBZ]

Well my truck is finally running again, but it's knocking pretty loud on the passenger side, something is definitely not right. I sent videos to DHD and they said they think it's injectors, so we checked the balance rates and they looked good, now I'm just waiting to hear back from them again. They also mentioned it could be a piston tapping a valve so were gonna run a borescope down in the cylinders and check that out, DHD has been great so far but I'm pretty nervous... Anyone have any other ideas? The thing that scares me is the injectors are almost brand new with 28,000 miles and ran perfect in the other engine, also when you crawl under the engine it gets really loud, a lot louder than it sounds from the top.

 

[PureHybrid]

Was it their short block or a long block?

 

[OleBlackyLBZ]

Short block.

 

[Chevy1925]

post the video

borescope it and then pull the valve cover and check your lash

 

[08lmm72mm]

Stuff like this is frustrating and expensive when it's already frustrating and expensive haha. Let's us know what you find.

 

[OleBlackyLBZ]

I cant figure out how to post the video. Valve lash was already double checked and looked great. He is going to borescope soon

 

[2004LB7]

you need to upload it to something like YouTube then use the media option here and add the link to the video for it to show

 

[OleBlackyLBZ]

I spent probably 15 minutes today trying to upload it, and i dont have social media or a youtube account. Ill keep ya'll posted tho.

 

[Chevy1925]

I spent probably 15 minutes today trying to upload it, and i dont have social media or a youtube account. Ill keep ya'll posted tho.

video files are generally too large to be uploaded and hosted here. you would need to create a youtube account and host it there, then embed the link here via the media option.

 

[OleBlackyLBZ]

Evan asked me to run a quart of 5w20 motor oil through the fuel system, he thought if it was the injectors it might quiet them down, so I dumped a whole quart in the 1/4 tank of fuel that was in the truck and drove it around for about 15-20 minutes. There was zero difference in sound. So he wants me to cut the oil filter open today and send him pictures. Worst case scenario if we can't fix it on our end without getting into the bottom end I will be driving the truck 12 hours to DHD and Evan said me and him would tear it back apart on a weekend and see what we could find. I have yet to meet anyone with luck as bad as mine lol

 

[Chevy1925]

well without some sort of way to hear the sound, we aint much help

did you tighten all the flex plate bolts? converter bolts? railer pressure matching desired? whats the mm3 main fuel rate at idle? any codes?

 

[OleBlackyLBZ]

well without some sort of way to hear the sound, we aint much help

did you tighten all the flex plate bolts? converter bolts? railer pressure matching desired? whats the mm3 main fuel rate at idle? any codes?

My mechanic is doing the work, he has done this all many times he works almost exclusively on duramaxes. He has done everything but assemble a bottom end, he builds allison transmissions as well.... No codes but we have not data logged yet

 

[Bdsankey]

Here are the videos he sent me.

Passenger side:

Source: https://youtu.be/775DyYRZv8A

Drivers side:

Source: https://youtu.be/UxbrPcmr_Ko

 

[OleBlackyLBZ]

Thanks for posting those videos Brad, rail pressure is 5300 at idle.

 

[juddski88]

I can't hear any abnormal knocking or tapping from those videos. It is loud, for sure. I hesitate to say nothing is mechanically wrong, but it sounds to me like injection quantity and timing just need some tweaking

 

[OleBlackyLBZ]

Tuning has not changed, same injectors and fuel pump also, just swapped from my other engine to this one. The other Engine did not sound like this and the knocking noise is coming from the passenger side. Tony Burhard and Evan at DHD have both seen the videos and agree something is not right.

 

[JoshH]

What pistons were used?

 

[OleBlackyLBZ]

What pistons were used?

New GM de-lipped lb7

 

[JoshH]

It's tough to tell much from a video, but it sure sounds more like fuel to me too. The reason I asked about the pistons is Fingers oval bowls are a little noisier and sound similar to that at idle, but being delipped LB7 pistons, I don't think that's what is going on here. Did you end up keeping the stock cam, or was it replaced for an AF cam of some sort?

 

[OleBlackyLBZ]

It's tough to tell much from a video, but it sure sounds more like fuel to me too. The reason I asked about the pistons is Fingers oval bowls are a little noisier and sound similar to that at idle, but being delipped LB7 pistons, I don't think that's what is going on here. Did you end up keeping the stock cam, or was it replaced for an AF cam of some sort?

Stock Cam keyed. I just think it's weird that it's on the one side.