What did you do to your NBS GMT800 Tahoe/Yukon Today?

[jcarriere]

Just installed my painted upper bumper cap and gave her a wash.

 

[Rocket Man]

Just installed my painted upper bumper cap and gave her a wash. View attachment 358656

Looks good. Did you paint the bumper cap?

 

[jcarriere]

No I had a local shop do it they did the bumper cap, 4 door handles and barn door handle as well as the mirror caps for $400.

 

[Walchit]

I'm no mechanic, but from what I've tried, and what I've read on the internet/watched on YouTube, I'm thinking cam bearings.
Over the last 500 miles it's seemed like it's been creeping more towards 10psi at idle instead of the 20 it Has had. I was thinking about putting a high volume oil pump on there, but I was afraid it would blow all my seals out.
I mean my problem was I had a feeling the dude I bought the truck from was a liar, and instead of telling my wife no, I said I didn't want the truck but it was up to her. Women's intuition wasn't working that day. Come to think of it, it probably never worked or she wouldn't have gotten with me lol

At least Gen 3s are plentiful and cheap! Any idea why she lost blood pressure

 

[iamdub]

I'm no mechanic, but from what I've tried, and what I've read on the internet/watched on YouTube, I'm thinking cam bearings.
Over the last 500 miles it's seemed like it's been creeping more towards 10psi at idle instead of the 20 it Has had. I was thinking about putting a high volume oil pump on there, but I was afraid it would blow all my seals out.
I mean my problem was I had a feeling the dude I bought the truck from was a liar, and instead of telling my wife no, I said I didn't want the truck but it was up to her. Women's intuition wasn't working that day. Come to think of it, it probably never worked or she wouldn't have gotten with me lol

Cam bearings are the first to be fed fresh oil and the first to starve of oil. If they're worn prematurely, that engine has had pressure problems before (failed oil pump, pressure valve or O-ring) or had coolant in the oil (Castech failure?) that wore out the bearings.

What's your plans- Used pullout? Reman'ed long block? Build-up?

 

[Walchit]

Cam bearings are the first to be fed fresh oil and the first to starve of oil. If they're worn prematurely, that engine has had pressure problems before (failed oil pump, pressure valve or O-ring) or had coolant in the oil (Castech failure?) that wore out the bearings.

What's your plans- Used pullout? Reman'ed long block? Build-up?

There was metal spatter welded to the inside of my pan when I changed the o-ring. I didn't know if that was something from the factory but it sure didn't seem like they would send them out like that. I did the motor medic flush like 500 miles ago, because I saw one dude on YouTube who the o-ring didn't work for, use it and then had 40 psi again. There was probably a 3rd video where his shit blew up too,

My dad has a 300k 5.3 in a rolled 06 Silverado. I was wondering if I could pull it out and rebuild it. But he also said it had 0psi while he drove it for like 5 minutes. So idk if between the motor in my truck and the one in his there is at least a good block 2 heads and a set of pistons.

But idk if I can afford to get it machined if the block is messed up, I've never built an engine, but it's looking like God wants me to learn how.

The junkyard this mechanic guy I know uses wants 1100 for a 150k miles motor.

Im for real out of money, so I'm gonna have to do this as cheap as possible. If there are any good videos, threads you guys can point me to I'm ready to start reading and watching them lol

 

[Walchit]

P.S. I went on the guys Facebook page that I bought it from and he has an Escalade he wants 11,500 obo for, and a Silverado for 38,000 obo.
I asked him about the lifetime warranty he told me the motor had after he couldn't find the paperwork for the transmission rebuild. He hasn't responded.

 

[Rocket Man]

There was metal spatter welded to the inside of my pan when I changed the o-ring. I didn't know if that was something from the factory but it sure didn't seem like they would send them out like that. I did the motor medic flush like 500 miles ago, because I saw one dude on YouTube who the o-ring didn't work for, use it and then had 40 psi again. There was probably a 3rd video where his shit blew up too,

My dad has a 300k 5.3 in a rolled 06 Silverado. I was wondering if I could pull it out and rebuild it. But he also said it had 0psi while he drove it for like 5 minutes. So idk if between the motor in my truck and the one in his there is at least a good block 2 heads and a set of pistons.

But idk if I can afford to get it machined if the block is messed up, I've never built an engine, but it's looking like God wants me to learn how.

The junkyard this mechanic guy I know uses wants 1100 for a 150k miles motor.

Im for real out of money, so I'm gonna have to do this as cheap as possible. If there are any good videos, threads you guys can point me to I'm ready to start reading and watching them lol

Here’s a good book on building an LS. It has lots of info. Not sure if it’s what you need but it’s a good start.

 

[Walchit]

That's cutting into my non-existent budget!

 

[Tonyrodz]

Truck is running pretty ****** again. Kind of like when the O2 sensor was getting lazy. Does anyone see anything strange? I just realized I didn't get the other O2 sensor.

Anyone have an idea?

 

[Rocket Man]

Anyone have an idea?

I don’t know much about fuel trims but i would say something there isn’t right. STFT for B1S2 is over 99%?

 

[Fless]

@Tonyrodz

B1S2 (the downstream sensor on the driver's side) doesn't seem to be awake. Is that one new? If the voltage constantly sits around 450mV it's not waking up. Can you see if the truck is going into closed loop? Check the power to the O2 heater circuit.

EDIT: would love to see graphs of the upstream and downstream sensors when the truck is warmed up.

 

[MassHoe04]

Anyone have an idea?

Unplug the upstream O2 sensor and see if it runs better. If it does, the sensor is bad. Replace, if necessary.
If that has no effect, plug it back in and check the top side for possible vacuum/air leaks.

Also... With reading that high, there should be a CEL. What code(s) do you have?

 

[MassHoe04]

@Tonyrodz

B1S2 (the downstream sensor on the driver's side) doesn't seem to be awake. Is that one new? If the voltage constantly sits around 450mV it's not waking up. Can you see if the truck is going into closed loop? Check the power to the O2 heater circuit.

EDIT: would love to see graphs of the upstream and downstream sensors when the truck is warmed up.

That might be something to look at.
But the downstream O2 sensors don't do anything that really impacts the engine running good or not. Upstream sensors have the most significant role in the computer's control over fuel/air.
I would try briefly disconnecting the upstream sensor on that bank, just to see if that makes the engine run better or not. No cost to rule out a bad sensor.

 

[Tonyrodz]

Pretty sure I replaced the ps O2 sensor, which @Scottydoggs helped me to diagnose--actually he diagnosed. My down stream O2's are tuned out, so nothing to worry about there. The only code I have is a maf sensor, P 0103. I've swapped to a known good maf with no change. It's a "soft code". It doesn't light the cel, but it's always there when I scan for codes. Been there since I got it tuned--tuner was an ice hole lol.

 

[Tonyrodz]

@Tonyrodz

B1S2 (the downstream sensor on the driver's side) doesn't seem to be awake. Is that one new? If the voltage constantly sits around 450mV it's not waking up. Can you see if the truck is going into closed loop? Check the power to the O2 heater circuit.

EDIT: would love to see graphs of the upstream and downstream sensors when the truck is warmed up.

How could I tell if it goes into closed loop?

 

[Fless]

How could I tell if it goes into closed loop?

Your scanner should tell you in the menu that displays powertrain values. Your Tech 2 would show it.

Here are the O2 heater fuses to check if you are so inclined (O2A is for front; O2B for the downstream):

 

[Scottydoggs]

Anyone have an idea?

your tech 2 should be able to show you the same things i used to scan the o2's. your looking for the o2's in Mv. and the fuel trims of both banks to really tell.

if the other side went bad i sure hope the bung dont twist out again.

tech two should also be able to tell you when it switched from closed to open. normally thats when it comes up to operating temps, or on its way there.

 

[Tonyrodz]

your tech 2 should be able to show you the same things i used to scan the o2's. your looking for the o2's in Mv. and the fuel trims of both banks to really tell.

if the other side went bad i sure hope the bung dont twist out again.

tech two should also be able to tell you when it switched from closed to open. normally thats when it comes up to operating temps, or on its way there.

I was thinking the same thing. I'm tempted to just take it somewhere to swap out the O2. I don't really want to deal with that again.

 

[Walchit]

The flashing MIL was a random cylinder misfire code.

Been watching cam bearing videos, I guess my first step is buying a cherry picker.