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

[Geoffsfas10]

Well... i think my motor is on its way out. Theres a new noise that started today at idle thats loud and belt or pully sounding but it was sounds much more metallic and might be coming from the drivers side. Which is also where the ticking comes from when it hits the right RPM range..... so neighbor and I are going to look into it wednesday. if it is lifter time, hopefully i can get parts and get it fixed before thanksgiving when we're supposed to take it to PA

 

[Geotrash]

Well... i think my motor is on its way out. Theres a new noise that started today at idle thats loud and belt or pully sounding but it was sounds much more metallic and might be coming from the drivers side. Which is also where the ticking comes from when it hits the right RPM range..... so neighbor and I are going to look into it wednesday. if it is lifter time, hopefully i can get parts and get it fixed before thanksgiving when we're supposed to take it to PA

Feel free to grab a video and post it up on YouTube, linking it back here.

 

[Geoffsfas10]

Feel free to grab a video and post it up on YouTube, linking it back here.

Yeah Im going to take one tomorrow when I have a chance and post it here. I might go into the engine forum so I can discus it more and keep easier tabs on the info.


Its odd, it makes enough noise that i can really only hear it when the windows are closed otherwise wind noise over powers it. I have no misfire, no lose of power, no glitter in oil, no CEL, nothing...still switches between v8/v4 modes smooth on the high way.....im so confused.

 

[iamdub]

Yeah Im going to take one tomorrow when I have a chance and post it here. I might go into the engine forum so I can discus it more and keep easier tabs on the info.


Its odd, it makes enough noise that i can really only hear it when the windows are closed otherwise wind noise over powers it. I have no misfire, no lose of power, no glitter in oil, no CEL, nothing...still switches between v8/v4 modes smooth on the high way.....im so confused.

You're 100% sure it's not an exhaust leak? The manifold at the head is the usual culprit, but you can't forget about the other end of the manifold at the Y-pipe.

Set your DIC to the screen that shows V4/V8 mode. Get in a position where you can hear it clearly while cruising. When in V4 mode, press on the pedal just enough to make it engage V8 mode and see if there's any corresponding change to the noise.

 

[Doubeleive]

6 speed 6l80e
SO... I had to drive an hour in very heavy rain, flooded roads and accidents galore, at the end of my trip I had to stop by wally world the rain had let up a little bit so I punched it from a light and the shift got a little herky-jerky with me like 2-3 3-4 around there, no codes or anything but seems like maybe something got wet or saturated?
when I got home I hooked up the tech2 and poked around, I was just looking and now I am wondering is the 109psi in park, normal? googled but didn't find diddly.
maf and intake was dry but could maybe need to be cleaned

 

[gooffeyguy]

6 speed 6l80e
SO... I had to drive an hour in very heavy rain, flooded roads and accidents galore, at the end of my trip I had to stop by wally world the rain had let up a little bit so I punched it from a light and the shift got a little herky-jerky with me like 2-3 3-4 around there, no codes or anything but seems like maybe something got wet or saturated?
when I got home I hooked up the tech2 and poked around, I was just looking and now I am wondering is the 109psi in park, normal? googled but didn't find diddly.
maf and intake was dry but could maybe need to be cleaned
View attachment 353630

@swathdiver he was asking about trans pressures a while back in a post and I hooked up my Tech2 and took some screen shots but don't have them anymore. I think it was around 109 in park though

 

[Geoffsfas10]

You're 100% sure it's not an exhaust leak? The manifold at the head is the usual culprit, but you can't forget about the other end of the manifold at the Y-pipe.

Set your DIC to the screen that shows V4/V8 mode. Get in a position where you can hear it clearly while cruising. When in V4 mode, press on the pedal just enough to make it engage V8 mode and see if there's any corresponding change to the noise.

See that was my initial thought because i feel like to started to notice this after i had the code for a bad o2 sensor. i replaced it and its on the same side that I replaced the sensor but its very much a metal on metal noise. But IMO, its WAY to quiet/inconsistent for a rod knock

Here's the other thing thats super confusing, on the highway in 6th gear, i sit at 1500 rpm at 60 ( 3.08 gears ) and it doesnt make the sound. If i down shift into 5th to go up a hill and i get to 2k rpm, no sound. going up a BIG hill hill it will go to 4th and i will hear what sounds like an exhaust leak at 2500ish to about 3k but thats all the longer i generally stay in it, it shifts back up and gets quiet. There is no audible difference it switching back and forth between 4 and 8 mode, only difference i see if the tach drops maybe 100-200 rpm.

 

[swathdiver]

@swathdiver he was asking about trans pressures a while back in a post and I hooked up my Tech2 and took some screen shots but don't have them anymore. I think it was around 109 in park though

Yes, all of us run 109 psi in the main valves and the other two fluctuate depending on gear and load.

 

[BG1988]

See that was my initial thought because i feel like to started to notice this after i had the code for a bad o2 sensor. i replaced it and its on the same side that I replaced the sensor but its very much a metal on metal noise. But IMO, its WAY to quiet/inconsistent for a rod knock

Here's the other thing thats super confusing, on the highway in 6th gear, i sit at 1500 rpm at 60 ( 3.08 gears ) and it doesnt make the sound. If i down shift into 5th to go up a hill and i get to 2k rpm, no sound. going up a BIG hill hill it will go to 4th and i will hear what sounds like an exhaust leak at 2500ish to about 3k but thats all the longer i generally stay in it, it shifts back up and gets quiet. There is no audible difference it switching back and forth between 4 and 8 mode, only difference i see if the tach drops maybe 100-200 rpm.

disable he v4 mode should fix the issues with a chip

 

[Doubeleive]

Yes, all of us run 109 psi in the main valves and the other two fluctuate depending on gear and load.

IN PARK? when I put it in drive the other solenoid went up to 109 (#2 i think) and in reverse another solenoid (#5 i think) went up to 109, back to park and #3 stays at 109?
it's been pouring rain here for over 24 hours straight when it quits I will take a look at the harness or take it by the transmission shop and have them take look, I think maybe
something is just wet. I am right in the dark red spot by SF