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

[Fless]

Probably quite a few of those in the Upull yards.

 

[hertahoe]

Hope everyone had a great Christmas! Been kinda busy and haven't posted much, but have done a lot to the Tahoe. Finally bit the bullet and purchased a Blackbear tune, front and rear pads and rotors, steering box (didn't fix the inch of play in steering wheel). Along with a t-stat and coolant temp sensor yesterday. It was weird timing that the fans seem to all of the sudden be blasting away after the tune. But once I sent them a follow up log (all data was good). They suggested it could be a t-stat. Then I thought, since I am already working in the area, let's do the valve cover gaskets since they were failing. Of course, my wife's Tahoe didn't have the petcock valve, so I had to remove bottom hose. Fans aren't running now, yes! Even have cold and heat coming from passenger side vents for now. Another item on the list is the blend motor behind vent...

 

[latvius]

 

[viven44]

Did my first oil change on the 02 Yukon, surprised to see it uses only 6 qts.. given that the newer year models use 8 qts.

Prior oil change had been done at 87K miles, I was at 91.5K. Refreshed to see no oil usage at all (I pour a quart or 2 between changes on one of my other trucks with a rear main seal leak, haha), oil color looked about the same or slightly better than Wife's 2024 after 4K miles (GDI and short trips )

6 Qts Walmart SuperTech 5W30 High Mileage Full Synthetic
AC Delco PF46E
Drain plug gasket Fel-Pro 70820

 

[Tonyrodz]

I still haven't had time to look any further into the brake situation. What else would cause a soft pedal that goes almost to the floor?

 

[latvius]

New head gaskets and extracted broken exhaust bolts

 

[clandr1]

I still haven't had time to look any further into the brake situation. What else would cause a soft pedal that goes almost to the floor?

I’m no expert but would have to think there’s either air, or a leak, in the system.

 

[Tonyrodz]

I’m no expert but would have to think there’s either air, or a leak, in the system.

It does have a leak in a rear line, but I'm not completely sure that's the sole reason.

 

[latvius]

It does have a leak in a rear line, but I'm not completely sure that's the sole reason.

Yeah you gotta fix that first, it doesn't make sense to me to troubleshoot further until that is fixed and then test the brakes to see what you have

 

[jfoj]

I still haven't had time to look any further into the brake situation. What else would cause a soft pedal that goes almost to the floor?

If this is on your 2003 and you have all the original steel brake lines, they need to be replaced unless you possibly live in the SW US where it never rains or snows.

Most of the original steel brake lines do not last much beyond 10 years on anything up to about 2006 when they went back to plating/painting the steel brake lines.

 

[Tonyrodz]

If this is on your 2003 and you have all the original steel brake lines, they need to be replaced unless you possibly live in the SW US where it never rains or snows.

Most of the original steel brake lines do not last much beyond 10 years on anything up to about 2006 when they went back to plating/painting the steel brake lines.

Im not sure if all the lines were replaced--I've owned it since 2012--the rears were definitely replaced as I blew them out slamming on the brakes once.
There's no drips of brake fluid under the truck. Only my rear ds.
Solid advice though. Thanks.

 

[mattbta]

Added some more boom booms. I converted to Lux Bose in my 2004 Hoe and last summer put a shallow 8 in a pre-03 factory box in the back so i had that and the oem. Wasn't real happy as the center console sub in luxury outperformed this thing.

So, impulse bought this on Amazon for $130 the other day after being influenced by youtube. Holy crap, it pushes some air. I just did a quick functionality test and will need to tune the amp.

 

[ivin74]

New head gaskets and extracted broken exhaust bolts


View attachment 447313

Replace the knock sensors, valley pan gasket and clean the oil pressure sensor screen since you are already there.

The heater hose T's are easy to change now that there is nothing on the way.

 

[Tonyrodz]

Replace the knock sensors, valley pan gasket and clean the oil pressure sensor screen since you are already there.

The heater hose T's are easy to change now that there is nothing on the way.

The GMT800's don't have an oil sensor screen, that's only the 900's and above.

 

[latvius]

Too late it's already back together

 

[Keviebear86]

I was able to pick up a 5.3 from a 2004 Sierra for free. If its worth rebuilding I will do it completely from pan to throttle body. I'm looking for suggestions on a mild cam and converter that I can use for daily driving/mild power upgrade. I'll have some other bolt on parts (long tubes/y pipe). Any help would be great!

 

[Matthew Jeschke]

I just dumped NaOH aka Lye solution aka drain cleaner into my exhaust. Results yet to be determined. Had a plugged cat figured why not. Disconnected flange to muffler. Shoved highly calibrated orange in there to plug hole (didn't have a potato). Removed both upper O2 sensors and proceeded to fill up with solution. Waited 1 hour removed orange and drained solution from exhaust. Then started up truck which proceeded to spat carbon chunks out everywhere. EGR temps at inlet versus outlet fluctuated dramatically as I drove it and idled it for a couple hours. During driving I made sure to get inlet temp as HIGH as possible by *ahem* rodding the living word I cannot say on here out of it. Got home checked inlet to out let and was right on the 20% delta for a healthy cat (previously output was cooler than input). Need to see if temps remain in check over next few drives. Truck felt MUCH more responsive. Long story short, there maybe something to lye solution as a cheap converter fix! FYI ~ Didn't want to use cata clean as it's base is acetone. Other posts say to put acetone directly in the tank. I feared that's too strong a solvent, which maybe (didn't want to find out) could dissolve engine seals. It would certainly decrease their life a bit IMO, how much? IDK.

 

[Matthew Jeschke]

Im not sure if all the lines were replaced--I've owned it since 2012--the rears were definitely replaced as I blew them out slamming on the brakes once.
There's no drips of brake fluid under the truck. Only my rear ds.View attachment 447339View attachment 447340
Solid advice though. Thanks.

I just replaced mine. HIHGLY recommend Classic Tube steel braided hose kit. It wasn't too much more than OEM rubber hoses.

Classic Tube SBH6057 Classic Tube StopFlex Brake Hose Kits | Summit Racing

Free Shipping - Classic Tube StopFlex Brake Hose Kits with qualifying orders of $109. Shop Brake Hoses, Sets at Summit Racing.

www.summitracing.com

 

[latvius]

Had AC delco TPMS sensors installed in all four tires and rotate/rebalance. The previous ones were cheap knockoffs and one went bad after a year and I didn't want to replace just one at a time.

 

[latvius]

Has anyone looked into replacing your side mirror glass? I can get a set heated with turn signal for $60 or I can get the drivers side with same AND autodimming for $330
I want to keep the autodimming feature but good god