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

[wjburken]

I installed drop spindles and during the process on the first side I must have been too rough and the wheel sensor must of got damaged. So I had to pull that side back apart again to install a new one and all was fine. I did the other side this weekend and was SUPER gentle with that sensor. But it still threw the code again. So I was super pissed off. I got another new one and installed that today. Ok in the driveway so far, test drive later will confirm. So super aggravating to have to dig back into both sides again after all the spindle work.

Then Saturday night it went into limp mode and got stranded 20 miles from home 10 oclok at night. I plugged my scanner in and got the P2135 code. This happened a few months ago one night too. I scanned and got that code and messed with the the plug on the throttle body and gave a couple of good slams to the throttle pedal and it went away. Until it happened again this night. Same code, did the same hail mary techniques. Fired up fine. When I went back under the hood as soon as I touched the harness plug it shut off. Gave it another "wishful wiggle" and started and ran fine. Drove home fine.

Just to clarify it only showed that one code during the initial stranding Saturday night. And I did not clear it.

Today after installing the new speed sensor I pulled the intake snorkel off to remove and check the TB sensor plug and wiring. I can not find anything wrong that stands out. I used compressed air to blow out the connection and plugged it back in tightly. The throttle body assembly was replaced around 40K miles ago with a Pep Boys unit.

When I fired it up after checking that plug all seemed fine on the dash board. I ran the scanner to clear the code and now found I have 3:

P1516
P2101
P2135

I cleared them all and will test drive tonight. Didn't look up the other codes yet because I am getting my ass kicked by this truck and everyone else and their fkng problems. So that is where I am at right now.

I have an appointment Tuesday to get this heap aligned and tires rotated and speed balanced. I told them I want before and after alignment readings so I can share here for your viewing pleasure. I took all my PPV center caps, bolts and spacers off so they don't f them up or loose them.

So…….Other than that Mrs. Lincoln, how was the play?

 

[iamdub]

Thanks for all the info dub, doub, and j91!

1 day sounds damn good. I will try and find the leak definitively before i go any further. If i can't find the leak by tomorrow morning, I might buy the UV dye.. it was only $10 but $30 for the UV flashlight..

yep it must be a tiny tiny leak..

As much as I would love to do the AFM delete, 1 day and $30 of headgasket I dont mind putting it off.. But getting it done would feel nice...

I forgot to factor in the cost of the head bolts, intake manifold and exhaust manifold gaskets. At Summit, bolts are only about $20 for the set for one side, exhaust gaskets are under $20 for a set and intake manifold gaskets are around $40. So, under $150 (with coolant and oil) and a day's work if it's just a gasket. I have mostly relevant pics and descriptions in my build thread if you need references.

But, it still may not even be a leaking head gasket. @Geotrash mentioned, them coolant Ts are a common suspect. When you park for the night, wrap a plastic grocery bag around 'em as sealed as possible and check 'em in the morning for coolant. Sometimes just stuffing paper towels in the suspected leak points works. But, if it's a really small leak, it'll just evaporate out of the paper by morning. Should have a smell on it either way.

 

[iamdub]

I installed drop spindles and during the process on the first side I must have been too rough and the wheel sensor must of got damaged. So I had to pull that side back apart again to install a new one and all was fine. I did the other side this weekend and was SUPER gentle with that sensor. But it still threw the code again. So I was super pissed off. I got another new one and installed that today. Ok in the driveway so far, test drive later will confirm. So super aggravating to have to dig back into both sides again after all the spindle work.

Then Saturday night it went into limp mode and got stranded 20 miles from home 10 oclok at night. I plugged my scanner in and got the P2135 code. This happened a few months ago one night too. I scanned and got that code and messed with the the plug on the throttle body and gave a couple of good slams to the throttle pedal and it went away. Until it happened again this night. Same code, did the same hail mary techniques. Fired up fine. When I went back under the hood as soon as I touched the harness plug it shut off. Gave it another "wishful wiggle" and started and ran fine. Drove home fine.

Just to clarify it only showed that one code during the initial stranding Saturday night. And I did not clear it.

Today after installing the new speed sensor I pulled the intake snorkel off to remove and check the TB sensor plug and wiring. I can not find anything wrong that stands out. I used compressed air to blow out the connection and plugged it back in tightly. The throttle body assembly was replaced around 40K miles ago with a Pep Boys unit.

When I fired it up after checking that plug all seemed fine on the dash board. I ran the scanner to clear the code and now found I have 3:

P1516
P2101
P2135

I cleared them all and will test drive tonight. Didn't look up the other codes yet because I am getting my ass kicked by this truck and everyone else and their fkng problems. So that is where I am at right now.

I have an appointment Tuesday to get this heap aligned and tires rotated and speed balanced. I told them I want before and after alignment readings so I can share here for your viewing pleasure. I took all my PPV center caps, bolts and spacers off so they don't f them up or loose them.

It seems you've possibly narrowed it down at least to one area. Now you gotta see if it's the TB or the harness or plug. Or maybe it's not the current issue and you just stumbled across another, somewhat related one.

 

[j91z28d1]

I installed drop spindles and during the process on the first side I must have been too rough and the wheel sensor must of got damaged. So I had to pull that side back apart again to install a new one and all was fine. I did the other side this weekend and was SUPER gentle with that sensor. But it still threw the code again. So I was super pissed off. I got another new one and installed that today. Ok in the driveway so far, test drive later will confirm. So super aggravating to have to dig back into both sides again after all the spindle work.

Then Saturday night it went into limp mode and got stranded 20 miles from home 10 oclok at night. I plugged my scanner in and got the P2135 code. This happened a few months ago one night too. I scanned and got that code and messed with the the plug on the throttle body and gave a couple of good slams to the throttle pedal and it went away. Until it happened again this night. Same code, did the same hail mary techniques. Fired up fine. When I went back under the hood as soon as I touched the harness plug it shut off. Gave it another "wishful wiggle" and started and ran fine. Drove home fine.

Just to clarify it only showed that one code during the initial stranding Saturday night. And I did not clear it.

Today after installing the new speed sensor I pulled the intake snorkel off to remove and check the TB sensor plug and wiring. I can not find anything wrong that stands out. I used compressed air to blow out the connection and plugged it back in tightly. The throttle body assembly was replaced around 40K miles ago with a Pep Boys unit.

When I fired it up after checking that plug all seemed fine on the dash board. I ran the scanner to clear the code and now found I have 3:

P1516
P2101
P2135

I cleared them all and will test drive tonight. Didn't look up the other codes yet because I am getting my ass kicked by this truck and everyone else and their fkng problems. So that is where I am at right now.

I have an appointment Tuesday to get this heap aligned and tires rotated and speed balanced. I told them I want before and after alignment readings so I can share here for your viewing pleasure. I took all my PPV center caps, bolts and spacers off so they don't f them up or loose them.

out.. that's brutal.

these fly by wire throttle body's have wasted so much of my time over the years. I truly dislike them.

one of my buddies has a c7 zo6. it's on its 2nd aftermarket larger ridiculously expensive one. and I honestly think his current issue is the Tb again.

 

[mikez71]

But, it still may not even be a leaking head gasket. @Geotrash mentioned, them coolant Ts are a common suspect. When you park for the night, wrap a plastic grocery bag around 'em as sealed as possible and check 'em in the morning for coolant. Sometimes just stuffing paper towels in the suspected leak points works. But, if it's a really small leak, it'll just evaporate out of the paper by morning.

Thanks, for the tips.

Heater t's were removed and heater plugged off, but not the rear aux lines. I dont think its from those lines, but will look for 1/2" caps or saran wrap it maybe.

Will pressurize this sucker once it cools down and leave it overnight.

 

[j91z28d1]

I seem to have lost that catch can thread. without actually walking out and looking haha. where are you guys plumping them I'm?

 

[mikez71]

Can't pressurize the cooling system! I pump and pump and no pressure.

Seals on tool look good. I can plug the air hole on the tool with my finger and build/hold pressure.
I can see coolant in the tank moving from the airflow (the corner by the cap).

I dribbled soapy water on the seams of the tank and the small hose to radiator, and all around the tool attachment.
can't find the leak but I didn't have a sprayer for the soapy water..

Not pushing water out, so I think it's leaking somewhere in the top air part of the reservoir.
When I remove the cap with engine warm (After cooling a bit), air rushes. I think it's vacuum, perhap the leak seals with vacuum.

I have a new tank and cap on the way, will probably get a couple of the small hoses as well.
I wanted to pull the small hoses and plug the reservoir, but I don't have any caps in that size.

Let me know if I'm doing something wrong!

 

[iamdub]

I seem to have lost that catch can thread. without actually walking out and looking haha. where are you guys plumping them I'm?

Easy there, jdpber.

I assume you're asking where we're plumbing them in. There's a rigid plastic pipe connected to a port at the rear of the driver's side valve cover, runs forward about 8" then makes a 90° curve to go to a port on the top center of the intake manifold. You'll have to pop off the beauty cover to see it.

The catch can goes inline in this circuit. So, in terms of flow, instead of going out of the valve cover and into the intake manifold, it goes out of the valve cover and into the catch can. Then, out of the catch can and into the intake manifold. How you connect the catch can to this pretty much doesn't matter as long as you have the flow correct. That plastic port on the intake manifold is very brittle and can easily crack off if you move it much at all. Safest method is to cut the plastic pipe where it makes that 90° turn a couple inches in each direction from the bend. So, you're basically removing that bend so you're left with two straight pieces of plastic pipe- one coming from the back of the valve cover and the other from that fitting on top of the intake manifold. Then, slip the hoses of your catch can over those short lengths of pipe and secure them with hose clamps.

IMO, the best location for the can itself is on the side of the alternator, bolted to that accessory bracket. It's easy to reach for draining and doesn't interfere with anything else.

 

[iamdub]

Can't pressurize the cooling system! I pump and pump and no pressure.

Seals on tool look good. I can plug the air hole on the tool with my finger and build/hold pressure.
I can see coolant in the tank moving from the airflow (the corner by the cap).

I dribbled soapy water on the seams of the tank and the small hose to radiator, and all around the tool attachment.
can't find the leak but I didn't have a sprayer for the soapy water..

Not pushing water out, so I think it's leaking somewhere in the top air part of the reservoir.
When I remove the cap with engine warm (After cooling a bit), air rushes. I think it's vacuum, perhap the leak seals with vacuum.

I have a new tank and cap on the way, will probably get a couple of the small hoses as well.
I wanted to pull the small hoses and plug the reservoir, but I don't have any caps in that size.

Let me know if I'm doing something wrong!

Have bolts you can screw into the hoses? You can do the same with the nipples on the reservoir, just wrap some electrical tape around a bolt to make it a plug.

 

[j91z28d1]

Easy there, jdpber.

I assume you're asking where we're plumbing them in. There's a rigid plastic pipe connected to a port at the rear of the driver's side valve cover, runs forward about 8" then makes a 90° curve to go to a port on the top center of the intake manifold. You'll have to pop off the beauty cover to see it.

The catch can goes inline in this circuit. So, in terms of flow, instead of going out of the valve cover and into the intake manifold, it goes out of the valve cover and into the catch can. Then, out of the catch can and into the intake manifold. How you connect the catch can to this pretty much doesn't matter as long as you have the flow correct. That plastic port on the intake manifold is very brittle and can easily crack off if you move it much at all. Safest method is to cut the plastic pipe where it makes that 90° turn a couple inches in each direction from the bend. So, you're basically removing that bend so you're left with two straight pieces of plastic pipe- one coming from the back of the valve cover and the other from that fitting on top of the intake manifold. Then, slip the hoses of your cartch can over those short lengths of pipe and secure them with hose clamps.

IMO, the best location for the can itself is on the side of the alternator, bolted to that accessory bracket. It's easy to reach for draining and doesn't interfere with anything else.

perfect.

thank you.