Unique issues to the GMT3x0 platform (break / fix / troubleshoot)

[Reprise]

A couple of weeks ago, I had seen a post that @The_Roadie contributed to where he mentioned things 'unique' to our platform (from a 'mechanical' perspective, not 'appearance').

While looking for that (which was just a mention w/ no specifics), I came across a post with more details as to what he was talking about (posted here for reference, although most of us know all about the items he brings up.)

My question - what other items (if any) are '3x0-specific' ? Not looking for a breakdown by subplatform, just relative to other GMT platforms.

If there are enough things that get listed here, perhaps this can be moved to the FAQ, for old / new members alike.

Here's Roadie's input:

Welcome! Nobody ever guesses right off the bat that:

1) A battery disconnect or discharge can cause HVAC issues

2) A battery disconnect can cause fluctuating idle that sometimes stalls the engine, but goes away when the AC is off, that you can fix for $4 worth of throttle body cleaner

3) Deteriorating motor mounts can cause a 10 Hz vibration at idle that's worse in DRIVE but goes away in NEUTRAL

4) GM would leave a red wire with a ring lug hanging in mid air near the fuse block with ZERO documentation what it does

5) That a scan tool failure can be caused by front fuse #13 that runs the accessory outlet

6) You have to change your transfer case fluid every 50K miles or you're looking at a world of $$ hurt

7) A numbnutz can try to jump start you, use attractively positioned studs with RED and BLACK wires near the battery, but they're really both 12V and the idiot just blew your 125A megafuse that takes out your radio and interior lights, but lets you start the engine when they jump start you properly to the battery terminals

8) Putting LED lamps in backwards can blow a stupidly named fuse (TBC) under the rear seat that will take out half of your interior lights

9) That a cold start might leave you with only 11V from the battery to run your vehicle for up to 30 seconds before the alternator takes over with a rush and gives you the 14V you're expecting

10) A HVAC blower component can fail in a way that your blower runs on after you take the key out of the ignition, and you have to search for the right fuse to prevent this from draining your battery in a few hours

11) You have essentially a NOISY-ASS shop vac under the driver's seat (on the frame rail) that runs for 30 seconds on a cold start, and it it fails, it will honk off the check engine light

12) Thermostats often fail in the open position, leaving you running too cold, and if left unfixed, can cost you a $500 catalytic converter

There are more - this is just the highlights of the GMT360 platform.

 

[Bow_Tied]

These rigs are so poor quality I don't know that you could ever list them all.

-Exhaust stud failures / ticking (I guess this is actually a lot of platforms)
-V8 DoD lifter failure trashes engine
-'05/06 V8s if you use the block heater when it's warmer than -19C the ECM code has a bug that loses track of the system variables. The truck starts and runs fine cold but thinks it hasn't warmed up when it has and gives a hard restart that mimics a failed coolant temp sensor unless you let it sit until it's cooled off again.
- rear air springs eventually get small leaks causing the rearend to sag overnight.
- there is a little fan thingy in the driver's B pillar that will squeak
- the bulbs in the HVAC and steering wheel buttons fail
- the steering wheel position sensor fails setting off the service stabil track light
- some models the oil pressure gauge is fake but others it works properly (but either are prone failure).
- if you are over 5'11" you will hit your head on the fully open tailgate.

fingers too sore to type more.

 

[Capote]

These rigs are so poor quality I don't know that you could ever list them all.

I'd have to respectfully disagree with you on that one. You gotta remember how old these trucks are now and most people experience only a handful of things listed, whilst they own the truck.

 

[Matt]

- some models the oil pressure gauge is fake but others it works properly (but either are prone failure).

That's a 4.2 issue, switch not a sensor. 5.3 has the proper sensor.

 

[littleblazer]

Sway bar end links...

 

[Sparky]

These rigs are so poor quality I don't know that you could ever list them all.

-Exhaust stud failures / ticking (I guess this is actually a lot of platforms)
-V8 DoD lifter failure trashes engine this is a 5.3L only thing, and only affects some, but yes, can be an issue
-'05/06 V8s if you use the block heater when it's warmer than -19C the ECM code has a bug that loses track of the system variables. The truck starts and runs fine cold but thinks it hasn't warmed up when it has and gives a hard restart that mimics a failed coolant temp sensor unless you let it sit until it's cooled off again.
- rear air springs eventually get small leaks causing the rearend to sag overnight. this is common on all airbag systems as they get old
- there is a little fan thingy in the driver's B pillar that will squeak
- the bulbs in the HVAC and steering wheel buttons fail this is pretty universal across many makes and models
- the steering wheel position sensor fails setting off the service stabil track light
- some models the oil pressure gauge is fake but others it works properly (but either are prone failure). 4.2L has the switch, 5.3L has a sensor. Can fail, but not constant.
- if you are over 5'11" you will hit your head on the fully open tailgate.

fingers too sore to type more.

Just some input.

I can' say they are that poor of quality rigs. My 02 made it to 215k without any major issues, aside from the rust that killed it. It had a failing fan clutch but it was original, so...

 

[Bow_Tied]

Thanks I didn't know those items were more common.

True Delta stats don't do these rigs any favours for reliability ratings. Maybe I am bringing the average down or maybe it's just 2006s. But I haven't yet had the exhaust manifold bolt or ignition switch issues which are nearly certain eventually it seems and my trans failed at 70k miles, steering rack around the same time, fuel sending unit and recently oil pressure sender... I am at the highest point of $ earning in my life and I can't keep up to the repairs on this thing. just about to roll 100k miles, Just my luck I guess; can't say I'll buy another GM product of this vintage again regardless of platform. But when it just happens to be working right, it is a great rig that looks, sounds, and pulls nice.

 

[JimInRadfordVA]

I've owned my 2005 TB LS I6 4x4 for about two years. It has about 120k miles on it. Aside from eating headlight relays (I can't believe that nobody has mentioned this yet), I have had no problems with it outside of normal maintenance. I love this truck so much, I'm already looking for one to stash away and replace this one when the wheels eventually fly off.

The positives for me (I'm handicapped) are: a)fuel fill on driver's side, and b) rear glass opens independently of rear hatch--allows me to access rear compartment without hassling with my wheelchair lift.

 

[Bow_Tied]

Oh yeah, sway bar end links. I have those to do too.

Just some input.

I can' say they are that poor of quality rigs. My 02 made it to 215k without any major issues, aside from the rust that killed it. It had a failing fan clutch but it was original, so...

I am honestly happy for you and others that have had few issues with these rigs. They might aged now. Compared to my '02 Pathfinder - the Envoy I have has had waaaay more problems in the first 3 years (same mileages for both) than the pathfinder had in over 7.

Looks like I am not the only unlucky one



I don't mean to be a gloomy gus, but this platform does not rank highly overall. That said, with good maintenance and some good luck they can be great vehicles that tick a lot of boxes other platforms can't.

 

[Reprise]

I appreciate everyone's replies - keep them coming!
While the listing of frequent / common problems is good, and there's a place for them - people can find those fairly easily, via search. And I know that not 'all' 360s will exhibit a specific problem. FWIW, I'm also more on the side of Sparky - things I've fixed, I knew needed to be fixed, and I haven't had 'new' issues crop up (except my trans, which was my fault, anyway). Maybe I just got a 'good one', but my LWB is a pretty solid vehicle, IMHO.

To clarify - I'm looking for things that GM may have introduced with the 360s, that most people probably don't know about (and especially things that also died during the 360 production run, so they won't be found on any other platform.)

I think (-?) the needed programming of certain new parts (digital HVAC control heads, etc.) falls into this category, and I'm sure there are others. Those are the things I was really thinking about for this thread.
Found another irascible Roadie reply (still not the one I was looking for) that may clarify further:

I would predict they wouldn't, because the evil design team on the GMT360 platform made as many things as possible incompatible with every other platform GM made. And then the team's parents discovered them missing from the nursery and came and took them all back home, so they could never commit the same insanity to another platform.

Again, thanks for the contributions so far!

 

[Bow_Tied]

Reprise, I am sorry for swaying your thread away from the original intent.

 

[littleblazer]

Oh yeah, sway bar end links. I have those to do too.



I am honestly happy for you and others that have had few issues with these rigs. They might aged now. Compared to my '02 Pathfinder - the Envoy I have has had waaaay more problems in the first 3 years (same mileages for both) than the pathfinder had in over 7.

Looks like I am not the only unlucky one

View attachment 83322

I don't mean to be a gloomy gus, but this platform does not rank highly overall. That said, with good maintenance and some good luck they can be great vehicles that tick a lot of boxes other platforms can't.

The other thing a lot of people overlook is that gm sold about a quartermillion of these things a year in the trailblazer trim alone. Pretty sure that Nissan didn't do nearly as well. It's not so much that the platform is bad it's that when you take a polling size a lot more people probably have experience with the platform. Opening that up also means a larger amount may have had problems. If the sample size is the same the percentages could be larger. I seem to recall reading that when new there was something like 1 in 120 had some issue and similar for the explorer. For BMW it was something like 1 in 90. (One of the reasons I'll never touch a BMW again... but that's a story for another day) nothing is really better or worse. I will say that Nissan builds one hell of a car. The 360 ended up being the test platform and option rolled into the full size later. It left me stuck once (fuel pump 150k) and that's it. Overall no really bad for the abuse I put it through. I understand where you're coming from though. We can all agree that dodge is just junk though right?

 

[Reprise]

Reprise, I am sorry for swaying your thread away from the original intent.

No need for an apology! I figured I wasn't clear enough when I started this thread, and wanted to correct that.

BTW, your third item about the block heater on the '05-'06 V8s - that's exactly the type of thing I'm talking about. No harm done!

 

[smt 59]

End links are a common fail or ware part on all vehicles that have them, I have owned mine since new and had minor issues but overall extremely happy with it. Although I am always tinkering with it and she is very well maintained. I have other manufactures in my personal fleet as well as the work fleet I maintain and overall our platform is better than most for the vintage of them. In general trucks are always higher maintenance than a car or crossover especially if they are 4WD. Btw I’m 5’10” and fit under the lift gate just fine but she does have a 3” lift and bigger tires. 😝

 

[littleblazer]

End links are a common fail or ware part on all vehicles that have them, I have owned mine since new and had minor issues but overall extremely happy with it. Although I am always tinkering with it and she is very well maintained. I have other manufactures in my personal fleet as well as the work fleet I maintain and overall our platform is better than most for the vintage of them. In general trucks are always higher maintenance than a car or crossover especially if they are 4WD. Btw I’m 5’10” and fit under the lift gate just fine but she does have a 3” lift and bigger tires. 😝

The 03 escalade and 07 sierra both are north of 200k and both are on their factory set of endlinks.... The straight through traditional styled ones are much better... they went to the 360 in 07?

 

[Sparky]

I still blame Isuzu's influence for the screwball wheel bolt pattern!

Any of the ball joint style end links wear faster regardless of brand. Just the nature of those things. The straight through bushing style ones do last longer. And they're easier to chop off when they do need replaced and the nut is seized up.

 

[littleblazer]

I still blame Isuzu's influence for the screwball wheel bolt pattern!

Funny you say that, our rodeo was 6 x 5.5 for 95...

 

[northcreek]

This might be of some interest:

 

[Reprise]

Wow...they actually *recommended* it...must be GMTN members Noted that the featured rig in the video shots was the TBSS - probably the scarcest of all.

Wonder how the '05 forward got the bump in crash test ratings - the '02-'04 were 'marginal' *with* the (then) optional side bags. We know the structure / sheet metal didn't change...

 

[Sparky]

05+ got side curtain bags instead of the in-seat side bags. Not sure what else would have changed to improve the offset impact though.