What did you do to your NNBS GMT900 Tahoe/Yukon Today?

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iamdub

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On my way home Monday night, I met up with a guy that had a Marketplace ad for a 5.3 from an '08 Sierra 4WD. The ad was a couple hours old and I was the first to actually plan to meet and follow through. He said he didn't know exactly, but he knows the mileage isn't higher than the 140s. His story is that his cousin bought a truck that needed some repairs and he ended up not being able to get the title. They parted out the truck and made money on it and he kept the engine to put in an OBS he was restoring. He later decided he didn't wanna deal with the wiring, etc., so he replaced the 4.3 with a 5.7 of the same era and let it ride. Now, wanting to clean out his shop, he put the LC9 up for sale with the transfer case from that truck and one from another truck, asking "$800 but make an offer". He seemed like a good 'ol boy, probably mid-50s, a Marine and a mechanic at a local large Chevrolet dealership. He had a really nice shop at his house with two 2-post lifts. Lots of LS and LT engines and parts stored all around and 6-8 GM vehicles parked near the shop and driveway. I didn't feel like I couldn't trust him. I said a partially disassembled pull-out on a stand that can't be ran or even spun over is technically worth "good" core price, which is $250-$400 in these parts. He agreed. I told him I'd feel that offering core price would be a lowball, and I wasn't even sure if I needed an engine so I was already risking a good bit, so I asked if $500 was too low. Thoroughly expecting him to counter with something like $700, I was surprised when he said "that's good". He just wanted to cull the herd. We shook on it and he said "but it's first come, first serve". I hauled ass home to at least pop off a rocker cover. It was around 10PM when I started.


I had a feeling it was the left side, so that's where I started and this is what I found:

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See it yet? Take a closer look. Of course it'd be the farthest one:

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The rocker and push rod appear perfect. Even the seal seems to be unscathed. I used a pen magnet to extract the locks. All cleared, I tried sliding the valve up and down- no dice. I tapped it with the head of a ratchet and it took about the force needed to drive a small finishing nail. So the piston definitely hit the valve and the stem is bent, but not so much that the valve can't move within it's normal range. So there's a chance I could get away with a new valve, guide and spring and buff out the piston. I won't know 'til I have the head off.

I decided that, due to needing it on the road ASAP, I was gonna drop in a known good engine if mine needed to come out. I didn't wanna be forced to settle for something sitting on the ground, under a tree in someone's yard as they tell me it has "about 50,000 miles". So, for $500, I could have an engine on standby. I think I could easily sell it If I didn't need it and get my money back. I told LC9 guy that night via Messenger (cuz it was now after midnight on Tuesday morning) that I definitely wanted it. He replied later that morning saying I was the first serious buyer but he had some others interested. I offered to send him payment to lock it down. I didn't feel it was a risk since I knew where he lived and worked, met his wife, etc.


Luckily, that day (yesterday), I was able to be home in time to unload the rocks from my trailer and toss on a large offroad tire to set the engine on. Garrett came to grab the trailer and me and we went 45 mins west to get the engine.

At one of our stops to check the straps. Yes, those are my old 22s:

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It came with the intake manifold. It wasn't bolted down so we set it in the back of the Tahoe. It's complete with throttle body, MAP sensor, fuel rail and injectors. It's identical to mine, which is FlexFuel. I'd really like to swap the cam and other AFM delete bits to the LC9 so I'd basically be back where I was before the failure, minus the heads. Unless I could get my driver side head fixed quickly enough. But, I don't wanna crack it open. I just wanna clean it, re-seal it and enjoy unmolested reliability. I'd be down about 100 HP, but I'd be able to run 87, which would be nice for my road trip.
 
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Charlie207

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As someone who's never "rebuilt" and engine before, how expensive is it for a basic OEM-spec DIY job? How hard is it (special tools other than engine stand?)

My 5.3 is at 158,*** miles, and I'm sure that's more cost effective than buying a new engine or dealing with a shop.
 

m1dn

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As someone who's never "rebuilt" and engine before, how expensive is it for a basic OEM-spec DIY job? How hard is it (special tools other than engine stand?)

My 5.3 is at 158,*** miles, and I'm sure that's more cost effective than buying a new engine or dealing with a shop.
Interested as well, but based on videos i've seen so far it doesn't look like you need stand at all :shrug:
Looking to take it apart up to lifters and change allll the seats and gaskets
 

iamdub

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As someone who's never "rebuilt" and engine before, how expensive is it for a basic OEM-spec DIY job? How hard is it (special tools other than engine stand?)

My 5.3 is at 158,*** miles, and I'm sure that's more cost effective than buying a new engine or dealing with a shop.

Interested as well, but based on videos i've seen so far it doesn't look like you need stand at all :shrug:
Looking to take it apart up to lifters and change allll the seats and gaskets


IMO, the Gen3 and Gen4 (but especially the Gen3) LS is the easiest engine to work on. It's cleaner due to the dry intake manifold and use of O-ring style gaskets. There's just a few points you have to be precise about, specifically the cover alignments. But, they're more fun than anything if you appreciate them instead of looking at them as a tedious task.

If I were to fully rebuild one, I'd strip it down to the block and let a shop clean, hone and replace the cam bearings. Then the rest is assembly by you that's like playing with a big, clean, metal SnapTite model.

A stand is cheap at Harbor Freight. Or, grab one for even cheaper off Marketplace from someone else that bought it for their one-time use and now wants to offload it. My half-ton model does perfectly fine for what I need. I do have it on a custom-made frame and large wheels for super easy and smooth rolling, though.
 

justchecking

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Hoover Dam!
View attachment 377445InkedIMG_0864.jpg

Got rear ended by an uninsured motorist. As always several mistakes led to this. First there was an accident about a mile ahead in the opposing lanes where a truck had run off the road and people were slowing down to rubber neck, second a few hundred yards ahead of us there was a wide load in the right lane so people were merging into the left lane to go around, third there was a 'hazard ahead' message and I took my foot off the gas to see what was up but I did not brake, third the young man behind us didn't leave enough distance. As I was slowing down I saw a white grill fill my rear view mirror so I pushed ******* the brake so he wouldn't push us into the car ahead of us and BAM! I really think he bent the frame a bit because i have to hold the steering wheel a half inch to the right on the highway now. Any guesses on the cost of this???
Got the Sub back unexpectedly soon today. New hatch ($1300) and new bumper cover ($950) and $2242 in labor and paint for total of $4492. I had to pay $500 since the other guy had no insurance. I also had a free rental for two weeks. Boy, when I got back in the Sub I felt like I was sitting WAY up high. Almost like when I was in the cub scouts and we got to tour the Monon yard and each of us got to sit in the engineers seat of a diesel locomotive. You sit WAY WAY up high.
 

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CaptainAmerica1

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My 4L60E just puked about 2 qts of fluid out of the dipstick tube… temps never got above 130
Well after all the steam dissipated, turned out to be the infamous heater hose and not the trans. The pressure from the hose exploding shot water under my trans dipstick and popped it up… sumbitch broke 300ft from my parking spot, talk about the best bad luck ever!!!
 

Tonyrodz

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Well after all the steam dissipated, turned out to be the infamous heater hose and not the trans. The pressure from the hose exploding shot water under my trans dipstick and popped it up… sumbitch broke 300ft from my parking spot, talk about the best bad luck ever!!!
Easy fix once you get it sorted out. Glad it wasn't the transmission.
Did you go oem or Dorman?
 

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