What did you do to your GMT today? [Part II]

BrianF

Member
Jul 24, 2013
1,185
West central Sask.
My wife tells me that the AC in the Trailblazer has died. Last year she says it was weak but we never really drove anywhere with it so never noticed.

Well no cold air. Fan works, checked fuses and swapped relays. Nothing. Did a rip down the road to increase airflow, no dice. Jumped low pressure switch.... no dice. Clutch is not engaging. So over the next few days I'll dig in further as I read into the system more.
 

Mooseman

Original poster
Moderator
Dec 4, 2011
25,177
Ottawa, ON
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BrianF

Member
Jul 24, 2013
1,185
West central Sask.
Moose, great post!! Thanks for that!! I have to ensure I'm getting voltage so I will check the fuse block and even jump the relay. Then move onto the unit itself.
 
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azswiss

Member
May 23, 2021
853
Tempe, AZ
Rather than wait for RA to send the missing exhaust valve stem seals I went to the local dealership and bought the kit. Yeah, it was nearly double the price but at least I was able to start working. Temps are 10-15degF lower than normal so I opted for comfort over cost. First couple of seals, both intake and exhaust, showed significant wear when compared to the new AC Delco OEM replacements. Had a little excitement when one of the valve keepers jumped and I could not find it right away; subsequently found it so all now good.
 
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sashainwy

Member
Nov 7, 2022
29
Wyoming
Bumper fascia was long overdue to be secured better on mom's TB. Years ago an impact left the bumper fascia hanging on the driver side, and loose on the passenger side. She had her handyman do a quick fix with a couple of stainless self tapping screws on each side. It's held all this time, but the gap on the driver side was over an inch, and everything was loose.

Removed it. Fashioned a replacement brace for the driver side, added some screws to the underlying plastic mounting point that's near each turn signal to eliminate their wobble. Reinstalled, tightened everything, and now we're good.


brace missing (at red arrow)
tbfacia02.jpg

passenger side brace
tbfacia00.jpg

driver side homemade brace
tbfacia01.jpg

kind of visible, not a big deal
tbfacia04.jpg

straight and firmly secured, gaps look good now
tbfacia05.jpg
 

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azswiss

Member
May 23, 2021
853
Tempe, AZ
Finished replacing the valve stem seals. Called it quits for the day just as the happy hour gong sounded; will button everything back up tomorrow. Out of curiosity, I compared the old vs. new seals using a go/no-go test with drill bits. The new seals were a firm go at 19/64" (.2968") and no-go at 5/16" (.3125"); the old seals were a loose go at 5/16" (.3125") for a difference of at least 1/64" (.0156"). The new seals have a lip at the inner edge of the seal face that wipes against the valve stem; that lip was gone on all of the old seals. Time will tell if this is the root cause of the oil consumption.

20230506_171017.jpg
 
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Blckshdw

Moderator
Nov 20, 2011
10,654
Tampa Bay Area, FL
CEL came on solid during the evening commute. I was dreading a P0305 again, but there was no hesitation or missing. Pulled up Torque at a red light to see this... :confused:

Screenshot_20230516_194217_Torque.jpg

I know I had replaced my IAT years ago, and I wanna say it's an aftermarket from AZ or something. Pulled up the live data and the temp readings were all over the place. HU wouldn't record, so waited until after I got home to record from my phone. Video was taken after the truck was parked for an hour, so that's why the coolant temp isn't at closed loop.


When I unplug the sensor, temp drops to -40 and stays there, so a new OEM IAT has been ordered.
 

TJBaker57

Member
Aug 16, 2015
2,892
Colorado
CEL came on solid during the evening commute. I was dreading a P0305 again, but there was no hesitation or missing. Pulled up Torque at a red light to see this... :confused:

View attachment 108293

I know I had replaced my IAT years ago, and I wanna say it's an aftermarket from AZ or something. Pulled up the live data and the temp readings were all over the place. HU wouldn't record, so waited until after I got home to record from my phone. Video was taken after the truck was parked for an hour, so that's why the coolant temp isn't at closed loop.


When I unplug the sensor, temp drops to -40 and stays there, so a new OEM IAT has been ordered.

I would check all associated wiring and terminals for a loose or mildly corroded connection.
 

Blckshdw

Moderator
Nov 20, 2011
10,654
Tampa Bay Area, FL
I would check all associated wiring and terminals for a loose or mildly corroded connection.

Yep, did check the wiring, nothing burnt or melted, although the loom had seen better days and that section coming off the coil pack bundle will need to get replaced. Connection was pretty solid when disconnecting and reconnecting the pigtail.

Truck seems to still drive fine, although my MPGs took a hit on this tank. I thought it may have been because I ran the AC during a few evening commutes, which I don't usually do. But if the air temp readings have been all over like this, I'm sure the PCM has felt like a frustrated parent with a bad ass child running around. :rotfl:
 

Blckshdw

Moderator
Nov 20, 2011
10,654
Tampa Bay Area, FL
New OEM IAT sensor (on the right) showed up today, popped it in and temps held steady as you'd expect. Almost time to fill the gas tank, so will be interested to see if my MPGs improve before the next time. :undecided:

20230518_183429_resize.jpg
 

northcreek

Member
Jan 15, 2012
3,295
WNY
Replaced the fuel filler assembly on the Nox. (Hard to believe that a 2015 could get this rusty) trying to chase down the cause of the PO442 code. Couldn't find any leaks pressure testing but, it probably would have leaked soon. Couldn't believe "made in USA"... :2thumbsup:
DA81FC57-CFC6-43C6-B986-0A460456EA3C.jpeg993E6C44-05D3-4B06-9CDE-BC97CF418F1B.jpegACC442A9-1FB0-41C8-8A28-0BFE0546B501.jpeg680792B1-BA84-40B2-921D-919B81F66854.jpeg
 

Mooseman

Original poster
Moderator
Dec 4, 2011
25,177
Ottawa, ON
The TB developed the usual noise in the front left. So ordered and got a hub from work. Once it came in, turned out to be an ACDelco Advantage. Took it anyway as the noise is pretty bad. And as luck would have it, my manager let me go early today because this week was a shit show, despite being only 4 days long, and I pretty much kept our dept going.

So got home, jacked it up and confirmed the noise:


I won't bore you with pics of the hub job however it did take me only 35 minutes from jack up to jack down.

However, during that job, found something else that will need attention:

IMG_20230526_153746_resized6443929304827023500.jpg

Looks to be the low pressure return line however I will replace both. In the meanwhile, I put some 75w90 gear oil, as recently suggested in another thread, to slow down the leak until I can get it done. It did quiet down the pump.
 

Mooseman

Original poster
Moderator
Dec 4, 2011
25,177
Ottawa, ON
Driving the Sierra to work today, got a low pressure warning on the RR tire. It was low but not dropping. Got it into the shop and there was a nail. Patched up fine. Good thing I found this out before the weekend and able to get it done at work for half price. Love this aspect of working at a dealership :2thumbsup:

I also ordered a tranny cooler thermal bypass "bypass" for the Sierra. The tranny runs a bit on the hot side, especially anytime while stopped. This will provide continuous full flow of fluid to the cooler. And if that doesn't cool it enough, I'll add fans to the 4"x33" cooler or add an aux cooler with fan. PPE also has a beefier cooler to replace the stock one but dang! it's expensive. I'll try other stuff first.
 

northcreek

Member
Jan 15, 2012
3,295
WNY
In chasing down the PO446 or better said throwing parts at it. I believe I found the culprit. Did a forensic on the replaced Purge sol/valve and found a ruptured valve membrane. Even with all the parts still only about $150.00 and some swearing.34D88DD6-5BFB-4EB4-9BE0-F45F50EB0A8F.jpeg562007E9-2AA2-4DE7-9DF3-1291F32CDEDB.jpeg
 

Matt

Member
Dec 2, 2011
4,009
In chasing down the PO446 or better said throwing parts at it. I believe I found the culprit. Did a forensic on the replaced Purge sol/valve and found a ruptured valve membrane. Even with all the parts still only about $150.00 and some swearing.View attachment 108522View attachment 108523

If it doesn't involve swearing, did you actually do anything?
 

northcreek

Member
Jan 15, 2012
3,295
WNY
Funny thing about this hunt/repair was that my wife started micro managing by saying things like “don’t put the new part in yet, let’s see how long it takes for the cel to come on”. Reminded me of the Seinfeld gas gauge episode with Kramer…lol
 

TollKeeper

Supporting Donor
Member
Dec 3, 2011
8,027
Brighton, CO
Hoping to pull the Envoy into the garage to reset the blend door motor. It was operating correctly, and its new last year, than I reset the battery, and it started clicking. I am thinking I installed it incorrectly, and never did a Recalibrate of the HVAC. And then when the battery got pulled, it auto-recalibrated.
 
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flyboy2610

Member
Aug 24, 2021
456
Lincoln, Ne.
In chasing down the PO446 or better said throwing parts at it. I believe I found the culprit. Did a forensic on the replaced Purge sol/valve and found a ruptured valve membrane. Even with all the parts still only about $150.00 and some swearing.View attachment 108522View attachment 108523
I replaced that on my wife's '06 TB last year when I had it torn apart to replace the valve cover gaskets. She'd been getting a CEL for emissions, and since the part was right THERE I replaced it.
 
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TollKeeper

Supporting Donor
Member
Dec 3, 2011
8,027
Brighton, CO
Blend for actuator reseated, and working perfectly!
 

azswiss

Member
May 23, 2021
853
Tempe, AZ
500 mile checkup on the oil level after replacing the valve stem seals. What a difference! Previously, I was seeing 1 Qt loss in 1000 miles (or less!) so I could expect to see ~ 1/2 Qt low at 500. Not any more; I am now seeing way under 1/4 Qt (more like 1/8 Qt). Looks like oil consumption is now in the range of 1 Qt per 3000 miles. Yeah boy!!
20230610_110929.jpg
 

Mooseman

Original poster
Moderator
Dec 4, 2011
25,177
Ottawa, ON
Replaced the passenger mirror with the one I bought from work.

Went from this: PXL_20230610_154630529_resized3919353645269378232.jpg To this: PXL_20230610_154637613_resized5310739507164074046.jpg

And I modified the driver side lower convex mirror to allow it to tilt higher. Just had to trim some plastic to allow more movement inside the ball socket.

And then did the oil change on the TB. Had been two years and 10k km, OLM at 20%. Was dark but not black. Opened the filter and it looked OK but kinda sludgy.
 

northcreek

Member
Jan 15, 2012
3,295
WNY
I replaced that on my wife's '06 TB last year when I had it torn apart to replace the valve cover gaskets. She'd been getting a CEL for emissions, and since the part was right THERE I replaced it.
Yeah, we're all good now, took a week for the evap monitor to reset, that seems to be the toughest one to get a reset on. Ready for the annual inspection now... :2thumbsup:
 
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Mooseman

Original poster
Moderator
Dec 4, 2011
25,177
Ottawa, ON
Motherf*cker! I treat it nice with a new mirror and this is what I get!

PXL_20230610_235858359.jpg

P0073. Ambient Air Temperature Sensor Circuit High
At least it's still under warranty. I'll bring it in to the shop on Monday.
 

Mooseman

Original poster
Moderator
Dec 4, 2011
25,177
Ottawa, ON
So took the Sierra and the light was now out. Didn't bother to get it checked as I just would get the "we can't check it if it ain't doing it" shtick. We shall see.
 

sashainwy

Member
Nov 7, 2022
29
Wyoming
Rust prevention completed. Mom's 2008 trailblazer spent most of it's life in Texas, then 4 years in Wyoming. Starting to see a teeny bit of surface rust here and there. She's about to move, so before I send her on her way with the TB, I did the undercarriage thing. Powerwash. RustKutter. FluidFilm. I'm new to this, and it's harder than it looks without a lift. Went through a gallon of FluidFilm. Didn't get the inside of the frame like I would have liked, but good enough for now. I'll get the inside of the frame more thoroughly next year when I visit.

A couple hours after powerwashing.
front-ff1.jpg

A couple of days after RustKutter.
front-ff2.jpg

And lastly the FluidFilm.
front-ff3.jpg

I'll start doing it yearly. I did a ton of maintenance to the TB, and hope to keep it in the family for another 10 years, or till the wheels fall off. ~s
 

northcreek

Member
Jan 15, 2012
3,295
WNY
Put new low beam bulbs in the Nox ( wife got pulled over by trooper, one was out ) never had to pull wheels/fender liners to change bulbs before.... :hissyfit:
 

TollKeeper

Supporting Donor
Member
Dec 3, 2011
8,027
Brighton, CO
Try changing a battery on a PTCruiser!
 

Mooseman

Original poster
Moderator
Dec 4, 2011
25,177
Ottawa, ON
Got a sweet deal on a pair of tubular running boards for the Sierra for $150. Saw some others that were asking up to $400. Contacted her and she even brought them to the restaurant we were at for Father's day. They looked good, a few little nicks and scratches but absolutely no rust. 6 bolts were missing to hold one tube to the brackets. Take the old crusty driver one out and put the new one in and... the rear bracket isn't far back enough. These must be for an extended cab, not the crew cab :mad: . So mount the rear bracket to the truck and mark the tube to drill new holes. Seems like all my drill bits were dull :frown: . Luckily I can access the inside of the tube via the plastic step cover so I can use some nuts instead of rivnuts. Turned out good and I have better ground clearance. I'll see if anyone would be interested in buying my old ones, which are fine except that the paint is peeling.

PXL_20230618_182426360_resized1613322253158602431.jpgPXL_20230618_192617399_resized8641964540397415656.jpgPXL_20230618_193212729_resized6240174837186997653.jpg
 

northcreek

Member
Jan 15, 2012
3,295
WNY
Finished installing a backup camera in the motorhome which was long overdue. Went with the old cable system which have really got reasonable since most go the wireless route. Got a smokin' deal on a open box kit.
I can see why people like the wireless kits after snaking cables under carpets, showers etc. but, it's in and works great ... :2thumbsup:
s-l1600.jpg
 

Mooseman

Original poster
Moderator
Dec 4, 2011
25,177
Ottawa, ON
Not mine, but my son's 11 Silvy. He asked that I bring my A/C stuff to the campground to fix his that stopped working. Hooked up the gauges and it just had a hair of pressure in the system. Vacuumed it to 30mm/hg and it held for over 30 minutes. It's probably just very slow seepage and is likely the first time it needed a recharge. Filled it with the proper amount and was blowing cold again. The went over it with the leak detector and couldn't find anything so we're calling it good for another 12 years.
 

6716

Member
Jul 24, 2012
821
Fresh headlamp assemblies!

Man, they look sharp. It's nice to do an appearance upgrade. A new front end rides nice but doesn't look any different. Now I want a fresh grille.

I got the TYC from O'Reilly. With the discount and free shipping they were like $0.80 cheaper than Rock Auto, and 2 days faster. Somewhere along the way I managed to lose the rubber covers for the headlamp ports, and I'd replaced one of the low beam connectors and it was kinda spliced a little ugly, and I was too lazy to try to buff the old ones out.


20230624_163826.jpg
 

6716

Member
Jul 24, 2012
821
I went from a $5 maintenance task to $130 in about 10 minutes.

Had a brake light out. Could have just spent $5 for one incandescent, but no. At the store I thought "LEDs are cool. I'll get those."

The assembly where the bulb was out was in pretty good shape for 18 years old. But since I got the cool LEDs, I gotta do both sides, right? The other side was a mess, one screw didn't have any bite left, where the assembly held another screw was cracked, and then two screws were corroded enough that they stripped out and didn't want to back out. I mean I probably could have made it work, but whatever.

So, replace the one assembly, right? But if I am going to replace the one side, I am going to replace the other side. Gotta balance. Except honestly after one dusty trail I don't know that I or anyone would have noticed one was new and one was not. The difference is not super dramatic like the headlight assemblies were. Oh, well.

The super white LED reverse lights are pretty cool, though.

I kept the incandescent turn signal bulbs that came with the assemblies, since the LEDs at the store didn't have the extra resistor bit and I didn't like the hyper flashing. I suppose I could pop for the LEDs with the extra resistor I found on line but the disclaimer says "these get hot, don't mount near plastic" and I'm like "but the whole assembly is plastic?"
 

Blckshdw

Moderator
Nov 20, 2011
10,654
Tampa Bay Area, FL
I kept the incandescent turn signal bulbs that came with the assemblies, since the LEDs at the store didn't have the extra resistor bit and I didn't like the hyper flashing. I suppose I could pop for the LEDs with the extra resistor I found on line but the disclaimer says "these get hot, don't mount near plastic" and I'm like "but the whole assembly is plastic?"

I mean, you COULD spring for an LM487 flasher relay to replace the OEM one under the dash. Would be plug n play, that'll fix the hyper flashing issue, and no resistors to get hot anywhere. Then you could really go all out and put LEDs in the front too while you're at it! :cool:
 

Mooseman

Original poster
Moderator
Dec 4, 2011
25,177
Ottawa, ON
Today was the day to replace the power steering lines in the TB and we all know how much fun that is! The pump had started whining as it lost most of the oil again. So I line it up to get it up on ramps and figured I'd put in in 4lo to make it easier. She goes into 4hi no problem, but then, when I put it in 4lo, the light flashes and goes out, but no service 4x4 light :confused:. Try all sorts of stuff, and on top of that, the transfer case is in neutral! Fack! Get the Tech 2 and I can control the brake and the disconnect but nothing to control the encoder motor itself. Anyway, it looks like a dead encoder motor. Pull it out and test it on the bench, the motor is toast. Find the spare I had from my old '02, tests good, put it in and had issues getting it timed right but eventually get it working.

Now on to the power steering lines. Pulled the fan for extra room and the R&P crossmember. Tried to pull them intact so I can figure out how to get them back in. Nada, broke both of them. Getting the long pressure line in took a while but figured to feed it from the back near the brake master and twisting and turning it. The low pressure line, being shorter, took less effort. Getting those cup seals out of the rack was a b!tch. Pried them out using a 90deg pick tool. I pre-punched those seals so I didn't have to try to push the lines to punch them. Got them in using the 8mm socket and extensions and hammer. Still took a bit of work with a pry bar to get the lines in and bolting the retainer using the 8mm socket and long 1/4" extensions. While I had the system open, I finally installed that Dorman PS cooler I picked up from the U-Pull. Was able to do it without having to remove the bumper. I muscled the old rusty one out and was able to get the new one in by basically inserting the lines backwards and then flipping it down and around and under (they said it couldn't be done :biggrin: ).

Buttoned everything back up, filled it, bled it with the wheels still in the air and heard the air gurgling out, topped it off again and started. The pump whined like a mofo so I moved the steering some more side to side, didn't help. Get it back on the ground and there is no power steering at all and the pump is smoking. Looks like the gear oil I used may have damaged it so I don't recommend this to anyone.

We have a saying in French, "Jamais deux sans trois". Never two without three. First was the lines, then the encoder motor, and now the pump. Checked Amazon and I can get a new pump with reservoir by tomorrow, which is good since most businesses here are closed as the Canada Day holiday was pushed to Monday. Might have to run around to find some more power steering fluid maybe at a gas station.

It was hot and humid out, horrid wrenching weather. I'm getting too old for this shit. The TB is really trying my patience.
 

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