What did you do to your GMT today? [Part II]
- Thread starter Mooseman
- Start date
MD_Envoy_Driver
Member
I plan on replacing the thermostat, water temp sensor and right side CV diff gasket/seal this weekend, but I found it was cheaper to order an entire crow-foot ratchet box end set than getting a single one! RockAuto keeps getting my business for a reason.
MD_Envoy_Driver
Member
Just did this on my 4.2, but managed to knock the shift linkage around enough so it pop off two days later. Man, that is one annoying fix to have to limp home after throwing it into DRIVE while the SUV is running.
Thanks Dorman for making good replacement parts here.
It looks like the cross-pipe has already been cut and welded. I don't know why that clamp needs to be there? I remember doing it on my Saab, it was tight but doable.
Leave it to GM engineers to put a hot exhaust pipe right under the tranny pan to bake the fluid.
Carfax show exhaust repair work done in 2021, I wonder this may not be oem config.It looks like the cross-pipe has already been cut and welded. I don't know why that clamp needs to be there? I remember doing it on my Saab, it was tight but doable.
Leave it to GM engineers to put a hot exhaust pipe right under the tranny pan to bake the fluid.
I have become the next guy they screwed up with didn't I? lol
Why they choose to skip drain plug for pennies is beyond meIt looks like the cross-pipe has already been cut and welded. I don't know why that clamp needs to be there? I remember doing it on my Saab, it was tight but doable.
Leave it to GM engineers to put a hot exhaust pipe right under the tranny pan to bake the fluid.
Last edited:
Update: I wonIt looks like the cross-pipe has already been cut and welded. I don't know why that clamp needs to be there? I remember doing it on my Saab, it was tight but doable.
Leave it to GM engineers to put a hot exhaust pipe right under the tranny pan to bake the fluid.
Blessed by Odin, my trusted hammer once again aids me during the most difficult time.
I was able to get the cover in, replenish fluid, start the car, run all the gears and feel the engagement. Just need a test drive to relearn.
ps: I find the breath hose for my rear diff with seized fill plug. Have anyone tried filling the diff by taking off the hose and add from breath port? If my cover is seized as well, I plan to add maybe half a quart and call it a day, see if there is any improvement. Right now it has a wine noise on highway.
pps: Would like to emphasis the importance of PPE. Please Wear It! From safety goggles, gloves, face masks, protective cloth to redundant vehicle lift protection. I was lazy and didn't use my goggles last night, and a splash of used transmission oil almost get into my eye. Luckily I wear regular glasses so get spared from a trip to ER. Shortcut PPE does not worth it.
Last edited:
I got it. I bought one bag of valvoline gear oil and two quart bottles as refill. Just squeeze the bag and I can hear the sound of fluid dropping into pan.
No oil change for my diff since 2009. oil is glidder and the steel pan is jet black, full of clutch material. Truck drive better afterwards. First time overhaul a vehicle and I'm proud of the progress.
The fresh oil is when I am experimenting with adding fluid from vent hole. It's jet black inside with sparkles and clutch material all over the place. It is a tough diff! I will taking proper care of in the rest of its life span.
With that said, this is the final chapter for my first stage restoration. No more work for a while!
PS: I cross thread one bolt. Will a new bolt fix it, or I need to put down new thread in the hole?
My 2005 Yukon 5.3 has an exhaust crossover that just barely prevents removal of the pan also. I just needed a smidge more. So I ran a 2x4 across and used some blocks to the frame rails and then a ratchet strap to pull that pipe down just a tad.
Matt
Member
- Joined
- Dec 2, 2011
- Posts
- 4,056
flyboy2610
Member
The handyman's REAL secret weapon: ratchet straps!
They also work good for getting the rear axle moved back over when you unbolt the shocks and track bar for a spring replacement!
... we, uh, will be spared from this when just replacing the shock, won't we?The handyman's REAL secret weapon: ratchet straps!
They also work good for getting the rear axle moved back over when you unbolt the shocks and track bar for a spring replacement!
The handyman's REAL secret weapon: ratchet straps!
They also work good for getting the rear axle moved back over when you unbolt the shocks and track bar for a spring replacement!
Useful for all manner of things. I prefer the one piece models.
After a 1200 km trip towing the RV trailer, I did an oil change on the Sierra at 33% OLM and about 8k km. Taking a hint from GM with their 6.2 debacle, I put in Castrol 0w30 European formula for gas/diesel engines. I no longer felt comfortable running the watery 0w20 GM specifies during summer months and towing. If increasing viscosity to 0w40 in their exploding 6.2 is good to help prevent damage, then it should be good in my little diesel. I might lose 0.1MPG though 
I was thinking of going to Rotella T6 0w40 but figured it was too much of a jump in viscosity and is an older formulation. Did see a couple of guys online that switched to 0w30 with great results. I do have a stockpile of ACDelco 0w20 that I will use during winter months and switch to 0w30 for the summer towing season.
I did see that 2019 and 2020 saw issues with chain stretch on the 3.0L diesel and my 2021 has the updated timing chain so I dodged that bullet. Still debating replacing the valve body in my 10 speed tranny to a modified one for over $1000USD. GM do have an extended warranty on the issue however are just using their own parts that still have the same defects. I'll continue doing my 50k km tranny fluid and filter changes. I'm at 88k km now.
I was thinking of going to Rotella T6 0w40 but figured it was too much of a jump in viscosity and is an older formulation. Did see a couple of guys online that switched to 0w30 with great results. I do have a stockpile of ACDelco 0w20 that I will use during winter months and switch to 0w30 for the summer towing season.
I did see that 2019 and 2020 saw issues with chain stretch on the 3.0L diesel and my 2021 has the updated timing chain so I dodged that bullet. Still debating replacing the valve body in my 10 speed tranny to a modified one for over $1000USD. GM do have an extended warranty on the issue however are just using their own parts that still have the same defects. I'll continue doing my 50k km tranny fluid and filter changes. I'm at 88k km now.
Which brand of 0w-40 you using Mooseman? And Euro spec oil cause no problem for us GM vehicle?After a 1200 km trip towing the RV trailer, I did an oil change on the Sierra at 33% OLM and about 8k km. Taking a hint from GM with their 6.2 debacle, I put in Castrol 0w30 European formula for gas/diesel engines. I no longer felt comfortable running the watery 0w20 GM specifies during summer months and towing. If increasing viscosity to 0w40 in their exploding 6.2 is good to help prevent damage, then it should be good in my little diesel. I might lose 0.1MPG though
I was thinking of going to Rotella T6 0w40 but figured it was too much of a jump in viscosity and is an older formulation. Did see a couple of guys online that switched to 0w30 with great results. I do have a stockpile of ACDelco 0w20 that I will use during winter months and switch to 0w30 for the summer towing season.
I did see that 2019 and 2020 saw issues with chain stretch on the 3.0L diesel and my 2021 has the updated timing chain so I dodged that bullet. Still debating replacing the valve body in my 10 speed tranny to a modified one for over $1000USD. GM do have an extended warranty on the issue however are just using their own parts that still have the same defects. I'll continue doing my 50k km tranny fluid and filter changes. I'm at 88k km now.
Styling upgrade for the radio antenna and change the rear lower control arm. I can feel the performance improvement, rear end is much tighter now.
Have a lot of fun trying to align the control arms. Eventually I used brake compression tool on one end and push the bolt as hard as I can while running impact drive to align the holes and push in. Not sure why it’s so hard on one side but not the other!
I used 0w30 Castrol Euro gas/diesel formula in my '21 Sierra with the 3.0L diesel. It's not a huge jump in viscosity and the zinc content is good for diesels. The only time zinc can be an issue is for vehicles with cats. Higher viscosity can be an issue with variable cams however the 3.0L does have a 0w30 version of oil for areas with higher temps.
Replaced the battery. After a marginal start last night I had it on the charger for 12 hours only to have it peak out at 12.4V and another marginal start. Got 3+ years out of this last one so no complaints (they really don't like the heat; typical life here in the desert is ~24 months). AAA Roadside came to the house and swapped in the new one all in for less than sticker price at AutoZone.
The front bumper plastic corner bracket had broken off and the bumper was flopping around. While taking off the two top bolts, they broke. Once I got it off, I then saw the bracket was completely gone and the bumper looked like it got hit with a scrape and a crack in it.
Ran to Kenny-u-Pull to get another one and also picked up a rubber cup holder liner that was missing in mine. While there, I saw an '06 that was horribly modified with a front rack that was booger welded to the front frame and a winch as well as e-fans. I guess the owner drank that Koolaid.
Used some 5 minute epoxy to glue the bracket onto my bumper and added some to the other bracket that was still there. While that was hardening, I decided to install the front tow hooks I had been hoarding ever since I scrapped my '02 EXT. Just cleaned the rust off a bit and painted them with some semi-gloss black rust paint.
For those two broken top bolts, while trying to center punch, I punched out the the weld-nut from the frame. Decided to punch out the other one and use plastic push retainers instead of bolts, which one was already in use in the middle. The bumper went back on no problem.
Then went to reinstall the grill and the right side "wing" broke off. This was the original grill from my '02 which I had Plasti-dipped black. I still have the original chrome one, I just have to find it and Plasti-dip it too. Most of the metal clips are also in bad shape.
Didn't get a lot of pictures as it was a 4H day (Hot, Humid, Hazy and Hot) and didn't think of that too much. If I can find the grill, I'll post an update.
Ran to Kenny-u-Pull to get another one and also picked up a rubber cup holder liner that was missing in mine. While there, I saw an '06 that was horribly modified with a front rack that was booger welded to the front frame and a winch as well as e-fans. I guess the owner drank that Koolaid.
Used some 5 minute epoxy to glue the bracket onto my bumper and added some to the other bracket that was still there. While that was hardening, I decided to install the front tow hooks I had been hoarding ever since I scrapped my '02 EXT. Just cleaned the rust off a bit and painted them with some semi-gloss black rust paint.
For those two broken top bolts, while trying to center punch, I punched out the the weld-nut from the frame. Decided to punch out the other one and use plastic push retainers instead of bolts, which one was already in use in the middle. The bumper went back on no problem.
Then went to reinstall the grill and the right side "wing" broke off. This was the original grill from my '02 which I had Plasti-dipped black. I still have the original chrome one, I just have to find it and Plasti-dip it too. Most of the metal clips are also in bad shape.
Didn't get a lot of pictures as it was a 4H day (Hot, Humid, Hazy and Hot) and didn't think of that too much. If I can find the grill, I'll post an update.
- Joined
- Apr 9, 2012
- Posts
- 1,046
Did a tune up on the Envoy (noticed MPG was dropping, and she felt a bit sluggish), driver side plugs were oil fouled. Seems like I may need to consider replacing the driver side valve steam seals to see if that helps. Plugs had about 50k on them since I changed it last, passenger side looked excellent with regular wear. However, shortly after the tune-up she developed a low-idle miss......and it can definitely be felt. Took about a week before she threw the CEL for #2 (P0302). Since the misfire timing coincides with the spark plug change, I must've damaged the plug from dropping it on the frame, or I screwed up the iridium tip/gap. I had completely blocked out of my mind, how much it sucks trying to get at #2. Ordered another plug, and set of wires to play it safe in the off chance I mangled either trying to re-install them.
I also need to crawl under, and pull the inspection cover on the bellhousing to see if the Rear Main is my confirmed leak. The spot in my garage and drive way has grown considerably over the last few months, so I'm beginning to wonder if the rear oil pan seal is the main culprit or the VLOM is leaking at the rear of the block and I just can't see it.
I also need to crawl under, and pull the inspection cover on the bellhousing to see if the Rear Main is my confirmed leak. The spot in my garage and drive way has grown considerably over the last few months, so I'm beginning to wonder if the rear oil pan seal is the main culprit or the VLOM is leaking at the rear of the block and I just can't see it.
- Joined
- Apr 9, 2012
- Posts
- 1,046
It looks like the cross-pipe has already been cut and welded. I don't know why that clamp needs to be there? I remember doing it on my Saab, it was tight but doable.
Leave it to GM engineers to put a hot exhaust pipe right under the tranny pan to bake the fluid.
Definitely a poor repair job, maybe my eyes are deceiving me....but I circled this part of their picture. The pipe leading off the cat looks like its was pounded in (circled it) for it to make that curve. Maybe its the lighting but that whole inside facing portion looks "flat" going into the bend.
I'm wondering if that was yanked off a regular GMT-800 and hacked to fit under there, something is way off with that setup....even for aftermarket.
Attachments
Took me a while to realize it is MY Saab lol. Yuck I hope it's not the case, although very likely. A muffler shop did work in 2021 but carfax report didn't show shop name...
I got new control arm bushing arrived, so when I work on that I will double check. Thanks!
- Joined
- Apr 9, 2012
- Posts
- 1,046
Yeeeep. Accessible through the wheel well while the strut is removed, or you remove the washer fluid reservoir/pull it out of the way to get access from the top. Top side isn't bad if you got small enough hands, otherwise I found a 5/8 spark plug socket with a hexagonal head to wrench it in/out to work well enough but its still a bear. Even worse when trying to seat the plug boot onto.
As much as I love the V8....I absolutely hate how cramped it is under the hood.
- Joined
- Apr 9, 2012
- Posts
- 1,046
Worked on the Envoy, and I was correct. I must've dinged the ground electrode, or it was already bent and I didn't notice it. Either way, the gap was way off causing the misfire. As a preventative measure, I had ordered 8 new BWD fuel injectors off RA and replaced the factory originals. Also added new Delphi ignition coils. What a difference, the idle is almost as smooth as the I6.
Changed out the brake booster check valve, and the pedal is nice and firm. Not as firm as the full size trucks, but it feels much better and the spongey feel is gone. Oh and I fixed the A/C! The culprit with my issue from last year, was a failing high pressure switch. Put a new one in, and at cruise I'm getting 38* F out of the vents (outside temp was 83 F at 80% humidity. Would blown 45* prior ), and the compressor is no longer cycling every 10 seconds especially when cruising.
Only thing left now is to finish my overhaul on the cooling system, already have the new radiator with a new T-Stat and hoses in addition to the trans cooler I need to add.
Changed out the brake booster check valve, and the pedal is nice and firm. Not as firm as the full size trucks, but it feels much better and the spongey feel is gone. Oh and I fixed the A/C! The culprit with my issue from last year, was a failing high pressure switch. Put a new one in, and at cruise I'm getting 38* F out of the vents (outside temp was 83 F at 80% humidity. Would blown 45* prior ), and the compressor is no longer cycling every 10 seconds especially when cruising.
Only thing left now is to finish my overhaul on the cooling system, already have the new radiator with a new T-Stat and hoses in addition to the trans cooler I need to add.
Attachments
Last edited:
On Friday, I replaced the grill on the TB as talked about in the last post. The old one had a broken wing. I found the original and it was still in good condition except it was chrome and I had already taken all the clips off so I ordered some from Amazon. More on that later.
Taped it up and since the bow tie was still in good condition, decided to keep it as-is. Put three coats of PlastiDip.
Here's from the previous post where the left and right bolts broke and I replaced them with plastic retainers. Seems to hold fine.
After drying, went to use the clips from Amazon and they don't fit. The hole where the grill's standoffs go into aren't wide enough. I wound up grinding then standoffs to make them fit the clips. I was afraid that doing this would weaken them and would break off the next time I would pull the grill but they are so weak that some pop off by themselves. I git them to stay in but I may have to spread them out more to make them hold better. Negative review of those clips already left.
Taped it up and since the bow tie was still in good condition, decided to keep it as-is. Put three coats of PlastiDip.
Here's from the previous post where the left and right bolts broke and I replaced them with plastic retainers. Seems to hold fine.
After drying, went to use the clips from Amazon and they don't fit. The hole where the grill's standoffs go into aren't wide enough. I wound up grinding then standoffs to make them fit the clips. I was afraid that doing this would weaken them and would break off the next time I would pull the grill but they are so weak that some pop off by themselves. I git them to stay in but I may have to spread them out more to make them hold better. Negative review of those clips already left.
I add a new backup key to my 9-7x. It is mind blowing that we can program key fob with door lock and immobilizer without special tool and hundreds of dollars service fee. One more negative view about modern car!
PS: I didn't know programming mode will wipe all previous stored key, so I found out master key no longer working after adding spare key, change master key battery, reprogrammed master key, then wondering why spare key not working, so program spare key again, then find out master key not working... lol lol! But all good now.
PS: I didn't know programming mode will wipe all previous stored key, so I found out master key no longer working after adding spare key, change master key battery, reprogrammed master key, then wondering why spare key not working, so program spare key again, then find out master key not working... lol lol! But all good now.
I think gmt360 has a stock trans cooler? May I ask which aftermarket ones your recommand?
- Joined
- Apr 9, 2012
- Posts
- 1,046
It does, the cooler is part of the radiator. I'm actually looking into adding one myself, when I take my radiator out to replace it. Hayden was recommended around here in the past, but your best bet is to make a thread or search older ones. I'm sure someone with experience having one can chime in.
Bad news, the exhaust is a hack job. Multiple places are hammered. Almost every turn has a flat spot. To the point that I have no idea how the exhaust actual works ok on my truck!
- Joined
- Apr 9, 2012
- Posts
- 1,046
Damn! Here I thought it was just the angle of the pic/light. I'm glad you were able to confirm it, but wow...
I'm actually shocked you aren't experiencing any kind of decreased performance (or if it already feels bogged down) from the restriction. Are you planning on gutting the exhaust, and putting a properly fitting one in place?
Had to have the Suburban towed home this morning. As I was leaving the neighborhood I thought I detected a little bit of slippage, nothing too bad, or so I thought. Two miles later as I was getting onto the freeway and accelerating down the ramp the slipping was undeniable. I was able to get to 60-65 but if I gave it any gas the revs went from 1500 to 4000 with no change in speed. Since I was only going another 2 miles I continued on to my destination and then called AAA for the tow back. The vehicle is an '03 and the trans is original with 192K miles on it.
This was a rapid onset issue; no problem yesterday, problem today. Will attempt some basic diagnosis work tomorrow to see if I determine anything specific. While I would love to find out it is something easy like a servo or a shift solenoid my gut says this is likely something internal and much more substantial.
This was a rapid onset issue; no problem yesterday, problem today. Will attempt some basic diagnosis work tomorrow to see if I determine anything specific. While I would love to find out it is something easy like a servo or a shift solenoid my gut says this is likely something internal and much more substantial.
It’s very weired, I don’t feel lack of power or extra loud exhaust. In fact I’m enjoying it like a bachelor visiting Amsterdam! My previous daily drive is an atkinson cycle hybrid, and boy what night and day. Gone are the days that I stuck on long uphill with no power nor torque. Now I downshift to third, let the rpm rise over 3k and feel the truck transforms into a rocket lol!
Of course, eventually new exhaust will goes in with new cam, lifter kits, rebuilt transmission & engine…
But that’s my 10-year road map. Right now I’m no issue and all smile
- Joined
- Apr 9, 2012
- Posts
- 1,046
Been driving the Envoy the last few days with the new plug in, so far so good. She still has a "slight" rough idle during the initial cold start, and it pretty much goes away after a few minutes or when shes slightly warmed up. May pull the PCM/BCM fuses, and let her sit overnight to see if it needs to just clear itself and relearn everything. Whle doing the injectors, I did swap the MAF and throttle body (TB kept making an odd noise, like it was sticking on opening/closing). If that doesn't do it, then I'm thinking the coolant temp sensor could be screwing with something. The original failed sometime after getting the Envoy, and I went with whatever Advanced had (might be a duralast sensor, I can't recall). I snaggd a Delco/Delphi stamped one to see if it makes any difference.
- Joined
- Apr 9, 2012
- Posts
- 1,046
Welp scratch that, the problem is back on #2 Cylinder. Broke out the VXDiag that has the Tech 2 emulation, and I'm seeing a misfire showing on #2, only under load. Idle it stays 0, small tap of the pedal and it starts counting (about 2-4 reporting). If the Weather permits, I'm going to try getting back under the hood and start diagnosing it. Ignition Coil was ruled out when I swapped it, so it leaves me wondering if the issue is the plug wire itself. So I'm gonna try swapping wires and see if the misfire follows to the next cylinder, if not, then I need to grab a compression test kit and see if maybe its a valve issue.
Welp my headlight washer pump stop working! I can see the nozzle pop out but no spurting. That probably means the relay and PCM is good, either the nozzle clogged or pump died. I always use orange Rain X washer fluid but on the 9-7x I went cheap and put in supertech washer fluid. Hope that's not what's cause the issue 