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

DenaliReyes said:

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Fun weekend part 1.
Rad flush and fill
Thermostat replacement.
Passenger side spark plugs.
Valley pan gasket.
4 post coolant hose gasket.
Knock sensors replaced and wire connection spliced and replaced.
Fuel injector o rings replaced, brown and blue.

Tomorrow is the driver side spark plugs, the intake manifold gaskets, the differential cover and drain and fill. Painting the calipers red. And looking for an AC leak.

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There's a lot I don't know. Like what's a valley pan gasket?

But what I do know is many have had the fittings go bad at the heater core. One of yours looked yellowish and it may be something to consider. Just my $.02.

But really...what's the valley gasket?

NoReverseYukon said:

Today, I had a brake pedal that went straight to the floor. Sure enough, a puddle of brake fluid back by the gas tank. Haven't investigated yet, but I do have a complete set of lines waiting to be swapped in; I guess that time is now!

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We've had 3 lines go on vehicles in our house due to rust over the years. I dont understand as much of a safety item the lines are that they arent stainless from the factory. Seems like it should be a requirement???

new2yukon said:

There's a lot I don't know. Like what's a valley pan gasket?

But what I do know is many have had the fittings go bad at the heater core. One of yours looked yellowish and it may be something to consider. Just my $.02.

But really...what's the valley gasket?

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exactly like it sounds it is in the top center of the motor under the intake manifold, it's also where the knock sensors sit.

new2yukon said:

We've had 3 lines go on vehicles in our house due to rust over the years. I dont understand as much of a safety item the lines are that they arent stainless from the factory. Seems like it should be a requirement???

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GM cheaping out to save a $1.

new2yukon said:

There's a lot I don't know. Like what's a valley pan gasket?

But what I do know is many have had the fittings go bad at the heater core. One of yours looked yellowish and it may be something to consider. Just my $.02.

But really...what's the valley gasket?

Click to expand...

Funny you mentioned the yellowing, because it started leaking this weekend after I placed as new thermostat.
Its where the knock sensors sit in. I took it off and changed the gasket. It was the farthest I've been inside an engine. Got to see the cam. Pretty cool.

I finished reinstalling everything g else with new I take gasket. New plugs and wires. Next weekend it's the o ring pick up tube. That's going to be a beachT

DenaliReyes said:

Funny you mentioned the yellowing, because it started leaking this weekend after I placed as new thermostat.
Its where the knock sensors sit in. I took it off and changed the gasket. It was the farthest I've been inside an engine. Got to see the cam. Pretty cool.

I finished reinstalling everything g else with new I take gasket. New plugs and wires. Next weekend it's the o ring pick up tube. That's going to be a beachTView attachment 249058 View attachment 249059 View attachment 249060 View attachment 249061 View attachment 249062

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So....the knock sensors are under the 2 round black covers that have the white wires, correct?

And why would I see oil on the front portion of that flat rectangular cover plate? I did valve covers a couple yrs ago and still get seepage in the middle flat portion under the butterfly.

Edit: ok. Saw YouTube video. How many estimated shop hours for the valley and intake gasket?

new2yukon said:

So....the knock sensors are under the 2 round black covers that have the white wires, correct?

And why would I see oil on the front portion of that flat rectangular cover plate? I did valve covers a couple yrs ago and still get seepage in the middle flat portion under the butterfly.

Edit: ok. Saw YouTube video. How many estimated shop hours for the valley and intake gasket?

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I would use some engine degreaser and pressure wash the entire area (from a moderate distance) and then see if it leaks fresh

i broke down and ordered 4 new window regulators. they all screech some, and the back pass side is now doing the herky jerky.

also set a code for the fuel tank pressure sensor. bought one of them as well.

so ive got a few things to fix. 4 reg's, tank drop and p/s the rear blend door actuator, had that part for months now, and still need to replace the wiper fluid pumps grommet. and with that im sure more plastic line will break and need to be patched up again.

new2yukon said:

So....the knock sensors are under the 2 round black covers that have the white wires, correct?

And why would I see oil on the front portion of that flat rectangular cover plate? I did valve covers a couple yrs ago and still get seepage in the middle flat portion under the butterfly.

Edit: ok. Saw YouTube video. How many estimated shop hours for the valley and intake gasket?

Click to expand...

Yes, I went the cheap way and bought 2 connectors to splice with the existing wiring. I just cut off the old.ones, they were brittle and broke as soon as I touched them. The knock sensors were originals I think, old and rusty. Bought all new parts from Rockauto.

It could mean your intake is taking in oil from the vacuum line of the pcv stem off the driver side valve cover. Mine was doing exactly that. Then it started to white smoke at start ups. I changed the intake manifold gaskets and it also added an oil catch can and that solved the smoke and the oil.

I changed the valley pan gasket because I'm already in there. Might as well change everything I can whilst the intake is off.

I broke the oil pressure switch like a dumbass I over tighten it. Snap. Cheap aluminum. Luckily the father in law came to the rescue and delivered one I just bought off oreillys.

Its slot of work I think but if you like doing your own mechanics. It will be cake. Easy. Take your time and do it right. I had my book with me just incase.

Sorry for the long story, but I would say it would take about 5 -6 hours. If you take everything off. Unplug all wires, remove gas line, vacuum lines, fuel injectors, coil packs, intake manifold, knock sensors, and then cleaning it all up. U might as well since u got it all off. Then put everything back together to spec. Yeah, it's a fun time. Enjoy! I did.

This is my second attempt .

Scottydoggs said:

i broke down and ordered 4 new window regulators. they all screech some, and the back pass side is now doing the herky jerky.

also set a code for the fuel tank pressure sensor. bought one of them as well.

so ive got a few things to fix. 4 reg's, tank drop and p/s the rear blend door actuator, had that part for months now, and still need to replace the wiper fluid pumps grommet. and with that im sure more plastic line will break and need to be patched up again.

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Are you sure you don’t want to just replace the fuel pump assembly while you have the tank dropped? That sensor comes as part of that assembly. Guess it depends on how many miles are on it.