LLY - Cracked piston

[DAVe3283]

If yours doesn't have a recess for the o-ring, then tightening the sensor all the way down will destroy the o-ring. I see they offer 2 kinds of sensors for the Duramax, one was tapered, and one with the o-ring. Usually the female side of a straight-cut o-ring fitting has a recess for the o-ring.

Is this the original sensor for your block?

If both the sensor and the block are straight-cut with flat surfaces and no o-ring pocket, you could just throw a copper crush washer on there and torque it to spec. That should work fine. I can't help but think we are over-complicating this whole process a bit

 

[NevadaLLY]

If yours doesn't have a recess for the o-ring, then tightening the sensor all the way down will destroy the o-ring. I see they offer 2 kinds of sensors for the Duramax, one was tapered, and one with the o-ring. Usually the female side of a straight-cut o-ring fitting has a recess for the o-ring.

Is this the original sensor for your block?

If both the sensor and the block are straight-cut with flat surfaces and no o-ring pocket, you could just throw a copper crush washer on there and torque it to spec. That should work fine. I can't help but think we are over-complicating this whole process a bit

It's the simple stuff!!! It's one of those no-brainer things you don't think about and then it comes back to haunt you lol. This is the original sensor. I'm thinking go copper crush and call it a day - maybe add a tiny bit of RTV for good measure.

 

[NevadaLLY]

Item 39. Anyone have the listing for this diagram or PN? I'm guessing its a copper washer, need to confirm. Mine likely fell off somewhere during this whole process.

 

[Chevy1925]

where did you get that diagram? thats not even where the sender goes unless its an 01-02 but its not showing the adapter the 01-02 has as well.

 

[NevadaLLY]

Funny - I just realized the same thing. Just an online exploded image of the block.

 

[NevadaLLY]

Put the new damper on - heat soaking the hub to 200deg worked pretty well, probably could’ve gone 250 to make it a bit easier. I was able to tap it 1/2 way on with a mallet then had to move to the crank bolt and washer. It sucked it in, but I definitely was worried about stripping the snout as it was probably 100lb-ft to turn it and suck it in. You can feel it bottom out against the cam gear which was good. Removed the bolt, installed the rest of the damper, and torqued to 74lb-ft plus 105*. Looks great and I hope it keeps harmonics in check.

 

[NevadaLLY]

I was working on the wiring harness and cracked a “casing” on the pigtail for the fuel pressure sensor. Does anyone know what that is or if I need to replace/fix. It’s about 4” long hard section with wires inside it, only about 1/8” diameter
I taped it up pretty good but whatever that casing is definitely cracked. Thoughts?

 

[2004LB7]

I'm pretty sure thats just a loom or plastic covering that got hard from heat. You will be fine

 

[NevadaLLY]

I'm pretty sure thats just a loom or plastic covering that got hard from heat. You will be fine

It looked like it had a copper lining, and epoxy on both ends. You can see where my thumb is some of the epoxy. I could see individual wires inside and the typical plastic loom was over the top of this. It was old and brittle which is why I was cleaning up when removing I cracked the piece underneath.

 

[juddski88]

It's a shielding cable splice.

 

[2004LB7]

As Judd said

 

[NevadaLLY]

As Judd said
View attachment 105780

Given that, should be ok with a crack. No connection to any circuit. Right?

 

[2004LB7]

Correct. If I'm not mistaken, it's the other side of the shielding that is grounded

 

[NevadaLLY]

yes used them on both coolant and oil. You can kinda see how it’s ran in this pic

I went to install driver galley feed - which location do you use? There's a bolt at the front of the block near the front cover (i think where the oil pressure sending unit used to be on LB7), but also another 2 plugs aligned with the oil pressure sending unit a little further back on the block which look like they feed into the oil galley. Want to make sure I use the right one.

 

[NevadaLLY]

I went to install driver galley feed - which location do you use? There's a bolt at the front of the block near the front cover (i think where the oil pressure sending unit used to be on LB7), but also another 2 plugs aligned with the oil pressure sending unit a little further back on the block which look like they feed into the oil galley. Want to make sure I use the right one.

I picked one that looked to be right above the front main cap side bolt.

 

[NevadaLLY]

So first start and break in drive had some minor and major hiccups. First, start it popped right up and built good oil pressure for 20-30 seconds. I then filled coolant and found I cracked an O-ring at the thermostat housing. Pulled things apart and fixed that. Added the rest of the coolant and all looked good. Started up and my new injectors are quite loud compared to before. There’s a pretty good “clatter” which I stethoscope’d to narrow down. A few are quite a bit louder than others. Feeling like that might just be a new injector sound and all was good, went for the first drive and made it about a mile and my hot side boost tube slid out of the boot. No biggie - threw that back on quickly. (Also, of course it had to start raining ) Finally got out on the highway and threw some miles on, everything looked perfect and engine seemed to start running fairly smooth. Still some injector clatter around 2k rpm but quiets right down as I accelerate past 2k. At 70miles - and to my complete surprise - injector line for CY5 BLEW A HOLE in itself! I bought the lines to avoid any issues, but caused one in the meantime. When I bought the new lines, I didn’t know a few of them were reman. These one that burst is a bostech and to me is simply unacceptable. So I was stuck on the highway with no fuel PSI. Grabbed a ride back to the shop and picked up my old lines. Ran back out to the truck and threw my “old” line on and I was back in business. By this time it was 2AM. More break in driving to come today. Power was awesome even in tune 1! I haven’t even gone WOT and you can feel it just ready to sing. PW monitoring on my Autocal looks like somewhere between 500-600 on tune 1.

 

[NevadaLLY]

So first start and break in drive had some minor and major hiccups. First, start it popped right up and built good oil pressure for 20-30 seconds. I then filled coolant and found I cracked an O-ring at the thermostat housing. Pulled things apart and fixed that. Added the rest of the coolant and all looked good. Started up and my new injectors are quite loud compared to before. There’s a pretty good “clatter” which I stethoscope’d to narrow down. A few are quite a bit louder than others. Feeling like that might just be a new injector sound and all was good, went for the first drive and made it about a mile and my hot side boost tube slid out of the boot. No biggie - threw that back on quickly. (Also, of course it had to start raining ) Finally got out on the highway and threw some miles on, everything looked perfect and engine seemed to start running fairly smooth. Still some injector clatter around 2k rpm but quiets right down as I accelerate past 2k. At 70miles - and to my complete surprise - injector line for CY5 BLEW A HOLE in itself! I bought the lines to avoid any issues, but caused one in the meantime. When I bought the new lines, I didn’t know a few of them were reman. These one that burst is a bostech and to me is simply unacceptable. So I was stuck on the highway with no fuel PSI. Grabbed a ride back to the shop and picked up my old lines. Ran back out to the truck and threw my “old” line on and I was back in business. By this time it was 2AM. More break in driving to come today. Power was awesome even in tune 1! I haven’t even gone WOT and you can feel it just ready to sing. PW monitoring on my Autocal looks like somewhere between 500-600 on tune 1.
View attachment 105788View attachment 105789View attachment 105790View attachment 105791

After driving today - the tune 1 and 2 have PW that are a bit too tight. Good for break in but the injector “clatter” is pretty significant and I’m getting quite a bit of smoke, cruising on light throttle like you might expect in a higher tune setting. I’m guessing PW is too tight and/or timing is too tight. Either way, going to go for a tune update. Reading back - sounds like 900+ for the lowest tune. I was seeing 600ish in tune 1. Thoughts?

 

[Josh154]

Could be tuning. Having used a few tuners on my lmm with 369 I noticed a lot of injector clatter with a certain tuner after I switched to 10mm pump. Was told it was just higher rail pressure. Both were running stock injectors. It didn’t bother me and truck ran great.

My lml with 200s and dual pumps is actually very quiet. More quiet than stock injectors and single cp3. Cruising down the interstate I can’t even hear exhaust with the compounds.

 

[Chevy1925]

After driving today - the tune 1 and 2 have PW that are a bit too tight. Good for break in but the injector “clatter” is pretty significant and I’m getting quite a bit of smoke, cruising on light throttle like you might expect in a higher tune setting. I’m guessing PW is too tight and/or timing is too tight. Either way, going to go for a tune update. Reading back - sounds like 900+ for the lowest tune. I was seeing 600ish in tune 1. Thoughts?

your tuning needs tweaking. its not a pulsewidth issue, it could be main injection timing, pilot timing or pilot pulse width causing it. Could even be a rail pressure issue. just going based off noise doesnt help us much, sadly. Id talk with your tuner.

 

[NevadaLLY]

your tuning needs tweaking. its not a pulsewidth issue, it could be main injection timing, pilot timing or pilot pulse width causing it. Could even be a rail pressure issue. just going based off noise doesnt help us much, sadly. Id talk with your tuner.

I ran some logs today, he said about the same thing. Saw MNinjtim at about 8*. I’m not very well versed on EFI live, but seems like pretty tight timing. Rail pressure at idle was hovering about 7-8k, I think is double from stock? Idle was a bit loud but not near as loud as the 1500-2100 rom range. Up above 2200 it quiets right down and power is smooth.