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

[the_tool_man]

I got to practice my tire changing drill this morning on the way to work. It's a good reminder to cycle the winch occasionally to keep it from seizing, and to check the spare tire pressure. Thankful for TPMS so I could pull over before the tire was damaged.

 

[Geotrash]

We bought a Tiffin Phateon a couple years back…so that whole “deciding it was too much” idea went out the window when purchasing a diesel pusher. We do however have to ensure to use truck stops and never use gas stations. There’s not nearly enough room with a toad attached, plus you can’t back up either.

Those are really nice. How many miles can you go between fuel stops?

 

[Geotrash]

and I wouldn't be having it done now if I wasn't going on a trip thru places where there is nothing around, I think the expected life is actually 165k is when they are known to start failing, i think @swathdiver has a running list
the gmt800's were rated for 100k, dealer told me they don't know what the rating is for the gmt900's but it seems to happen as stated, hell the thing could go 300k you never know. I just don't want to get stuck with my pants down. I already had planned to do it so a pinch of salt in a wound and carrying on. lol

That was a wise decision, although the one in my '07 went 215K before it started talking (fuel pressure regulating problems), and another 5K before I figured out what was happening and had it replaced with an OEM one. Shop only charged me $300 in labor. I was pleased.

Would love to see that list! Should be a sticky.

 

[wjburken]

That was a wise decision, although the one in my '07 went 215K before it started talking (fuel pressure regulating problems), and another 5K before I figured out what was happening and had it replaced with an OEM one. Shop only charged me $300 in labor. I was pleased.

Would love to see that list! Should be a sticky.

My 2007 was at roughly 230K when I started having issues with mine. It would leak down fuel pressure as it sat so I had to try and start it twice. Once to get it almost up to pressure, then the 2nd time to actually start. Was able to time it to when I had an almost empty tank and do it in my driveway.

 

[Doubeleive]

That was a wise decision, although the one in my '07 went 215K before it started talking (fuel pressure regulating problems), and another 5K before I figured out what was happening and had it replaced with an OEM one. Shop only charged me $300 in labor. I was pleased.

Would love to see that list! Should be a sticky.

historically 160k or after is the point when some things start to go goofy, die, malfunction. This doesn't mean it will happen to everyone all at the same time
it's just a "average" of sometimes individual things like alternator, hubs, water pump, sensors, throttle body, knock sensors, seals and gaskets, calipers, etc.
and it's not just gm it's all brands and it is a reason why you will see cars in the junkyard starting with 160k (or more) but a lot of them are around 160k and is unusual to see them with less than that and it is a reason why people will sell them at that point because they do not want to spend the money to maintain them because they feel it will just become a money pit or maybe it is.
Maybe things have changed in the last decade but I used to go to junkyards a lot there are several around me in almost any direction and you could walk around and pretty much knock on wood that most cars out there had at least 160k on them.
I am not trying to be a alarmist or tell anyone to go replace a bunch of stuff, it's just an observation I have seen and have even asked the "old guys" at the yards
if you want to go buy a used engine at a junkyard that's not one that pays for the "fresh" vehicles, then a lot of the engines are going to be around 160k or more with mileage and if they have something with less it's going to cost more.
I am at 160k on the yukon and it is in pretty good shape I maintain it well and I have driven it hard and have already done a lot of things but I know I can expect some things to start going in the future like door lock actuators, window regulators, hatch motor, misc sensors, switches. who knows but I won't be surprised
some people baby their cars never push the pedal hard, never tow, just cruise and hardly nothing ever fails
that is the advantage of buying from a old person that has been gentle on there vehicle.

 

[swathdiver]

and I wouldn't be having it done now if I wasn't going on a trip thru places where there is nothing around, I think the expected life is actually 165k is when they are known to start failing, i think @swathdiver has a running list
the gmt800's were rated for 100k, dealer told me they don't know what the rating is for the gmt900's but it seems to happen as stated, hell the thing could go 300k you never know. I just don't want to get stuck with my pants down. I already had planned to do it so a pinch of salt in a wound and carrying on. lol

No, I don't have a concensous on our fuel pumps but several of us have been reporting our fuel pump trims to compare their conditions to one another. Mine used to be rock solid at 43.5 psi all the time, even at WOT. Then one day it slipped a psi while accelerating and came back up and now waffles around while driving but only 2 psi.

The trim is in the 1.5s now and there is a new one sitting on my shelf in the garage. Soon as the weather cools off it's going to get changed before we head west to Monument Valley.

Will also be changing out all of my u-joints too. Almost 190K and nothing wrong but now have the press and tools do it at home properly and don't want any issues on that 5K mile trip.

 

[swathdiver]

I think I'll stop by the dealer and have them check the cap part number. had to believe the online stuff saying 20psi.

 

[Doubeleive]

View attachment 402994

YA weird I thought it was 15psi, but looks like it is 20psi

 

[swathdiver]

YA weird I thought it was 15psi, but looks like it is 20psi

I couldn't remember either and looked it up real quick!

 

[j91z28d1]

View attachment 402994

nice.. yeah that's crazy high sounding.

I'm going to replace it for the heck of it when I do the T's.

 

[j91z28d1]

No, I don't have a concensous on our fuel pumps but several of us have been reporting our fuel pump trims to compare their conditions to one another. Mine used to be rock solid at 43.5 psi all the time, even at WOT. Then one day it slipped a psi while accelerating and came back up and now waffles around while driving but only 2 psi.

The trim is in the 1.5s now and there is a new one sitting on my shelf in the garage. Soon as the weather cools off it's going to get changed before we head west to Monument Valley.

Will also be changing out all of my u-joints too. Almost 190K and nothing wrong but now have the press and tools do it at home properly and don't want any issues on that 5K mile trip.

are you seeing the psi moving around on a scanner or a real. gauge? are all these the returnless type? so much stuff is different on these hybrids, I'm always left wondering what's normal and what's not haha. I should probably take a look at mine


my experience with my 96 tahoe and my old camaro days u joints is replacing never worked out 100%. I would buy new drive shafts from gm (or junkyard for the camaros) or I always had a vibration at high speeds even when a drive shaft shop took me back and showed me their balancer said it was fine.

 

[swathdiver]

are you seeing the psi moving around on a scanner or a real. gauge? are all these the returnless type? so much stuff is different on these hybrids, I'm always left wondering what's normal and what's not haha. I should probably take a look at mine


my experience with my 96 tahoe and my old camaro days u joints is replacing never worked out 100%. I would buy new drive shafts from gm (or junkyard for the camaros) or I always had a vibration at high speeds even when a drive shaft shop took me back and showed me their balancer said it was fine.

I use the data from the Torque Pro app on my phone or the Tech-2 for the fuel pressure. I have had my Tech-2 connected to two GMT900 hybrids and they also ran at 43.5 psi like mine.

Haven't changed a u-joint in decades as we'd been driving FWD minivans until I bought the truck. Never had a problem back then.

A common problem is that folks will buy a Spicer 1350 and jam the retainers into place which causes binding issues. We run AAM 1355 joints which Spicer also carries but too many get the wrong parts and have issues.

I'll try to remember to photograph or video us changing them and what to look out for when we do it.

 

[Doubeleive]

are you seeing the psi moving around on a scanner or a real. gauge? are all these the returnless type? so much stuff is different on these hybrids, I'm always left wondering what's normal and what's not haha. I should probably take a look at mine


my experience with my 96 tahoe and my old camaro days u joints is replacing never worked out 100%. I would buy new drive shafts from gm (or junkyard for the camaros) or I always had a vibration at high speeds even when a drive shaft shop took me back and showed me their balancer said it was fine.

return line systems were done away with years ago probably around 2002/2003 as far as I know

 

[Life_Of_TC]

It's white powder. Everything works better with the white powder... for a few months anyway.

Yeah then you gotta work a 12 step program after

 

[gooffeyguy]

Getting ready for a camping trip with the 2012 towing mule later this week and thought I’d change the oil. Talk about pulling a string. Noticed that my oil cooler lines have gone from a seep to a steady, slow drip. Wait… is that an orange stain below my drivers side motor mount? Fuuuuuuck.

Buttoned up after the oil change and went for a drive. Strange noises coming from my left front wheel. Got home, jacked up that side and sure enough, play in the bearing. Good lord.

So I decided to get it done. Replaced the wheel hub, swapped the motor mount with the Hummer mount I’ve had waiting for this, and installed new cooler lines. All from my new parts stash. 6 hours later and it’s time for bed!

View attachment 396563
View attachment 396564
View attachment 396565

I know it's been a couple months since you did this, but I have a couple questions.

My oil lines are seeping and I have a small leak above the oil filter. I was thinking of changing these lines out when I change out the exhaust manifold bolts and gasket. I already installed the Hummer mount a couple years ago.

Did you remove the wheel well liner and do this from the side? Did you have to unbolt the front driveshaft u-joints and lower the shaft to get to the oil cooler bolts? And finally, with me already having the smaller Hummer mount, do you think I'll have to remove it for line clearance?

 

[Geotrash]

I know it's been a couple months since you did this, but I have a couple questions.

My oil lines are seeping and I have a small leak above the oil filter. I was thinking of changing these lines out when I change out the exhaust manifold bolts and gasket. I already installed the Hummer mount a couple years ago.

Did you remove the wheel well liner and do this from the side? Did you have to unbolt the front driveshaft u-joints and lower the shaft to get to the oil cooler bolts? And finally, with me already having the smaller Hummer mount, do you think I'll have to remove it for line clearance?

Yes, I removed the liner and worked from both the top, side and bottom. Couldn't have done it with the liner in, I don't think. And yes, I think you will also need to remove the motor mount temporarily to get enough clearance to maneuver the hard lines out/in. :-(

 

[j91z28d1]

return line systems were done away with years ago probably around 2002/2003 as far as I know
View attachment 403013

noticed the hybrid has to have a different rating lol. 50-75 key on because of course they do lol. why you'd need all this extra fuel pressure and oil pressure in a system designed to run the engine as little as possible.

crazy truck.. but it keeps me interested at least so far. I'll have to see if I have a fuel pressure pid on torque next time.

 

[gooffeyguy]

Yes, I removed the liner and worked from both the top, side and bottom. Couldn't have done it with the liner in, I don't think. And yes, I think you will also need to remove the motor mount temporarily to get enough clearance to maneuver the hard lines out/in. :-(

Oh, did you use OE GM replacement oil cooler lines, and did it come with the gasket? When looking on RockAuto it doesn't show or say if it does

 

[Geotrash]

Oh, did you use OE GM replacement oil cooler lines, and did it come with the gasket? When looking on RockAuto it doesn't show or say if it does

Yes, I did, and yes it does.

 

[89Suburban]

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.

This hit me again last night. Had to limp home. Had to hoof it to work this morning. Gonna borrow the F-150 work truck for the weekend while I try to attack this. Plan is to replace the pedal sensor assembly and go from there.