Stop sale on 6.2l vehicles

rusty503 · November 30, 2020

I went to my local chevy dealer for an oil change on my Silverado on Friday. While there I noticed a new Camero and a new Silverado idling at a fairly high rpm outside the service bays. There were running floor fans pointed at the radiators. A service advisor told me later that all vehicles with the 6.2 engine had a stop sale on them until they had run the engines for 4.5 hours. He said it had something to do with the valves. I guess it has to do with the valve springs?

econometrics · November 30, 2020

Wow, that would be a real PITA if that was a GM order for the dealers. I haven't heard of this yet.

HK_Crew · November 30, 2020

This is a known issue for several months know.

https://gmauthority.com/blog/2020/09/new-service-bulletin-addresses-valve-spring-issues-in-gm-v8-engines/

newdude · November 30, 2020

Yep. Valve spring failure test for 6,000 vehicles with a 6.2 engine. N202319660 Valve Spring Failure

Techs are instructed to hook up a laptop and via GM GDS2 set the throttle to 2,000rpm and leave it running for 4.5 hours, checking it every 25 minutes or sooner. During the test, they have to watch for any leaks, misfires, abnormal valve train noise and check engine light. If it fails during the test, they have to call GM TAC to proceed with what to do to fix it. If it passes the 4.5 hour run, they then take it on a 10 mile test drive in manual mode, keeping the engine at 2000-3500rpm. If that passes, change the oil and ship it/put it back on the lot.

econometrics · November 30, 2020

2 hours ago, newdude said:

Yep. Valve spring failure test for 6,000 vehicles with a 6.2 engine. N202319660 Valve Spring Failure

Techs are instructed to hook up a laptop and via GM GDS2 set the throttle to 2,000rpm and leave it running for 4.5 hours, checking it every 25 minutes or sooner. During the test, they have to watch for any leaks, misfires, abnormal valve train noise and check engine light. If it fails during the test, they have to call GM TAC to proceed with what to do to fix it. If it passes the 4.5 hour run, they then take it on a 10 mile test drive in manual mode, keeping the engine at 2000-3500rpm. If that passes, change the oil and ship it/put it back on the lot.

Wow. What a PITA.

BluegrassMotorsport · December 1, 2020

Mine was produced right at the very beginning of the timeline in question. I'm 5,000 miles in with no issues yet so I feel like I'm alright. Definitely a crappy situation.

bjr2020 6.2 · December 6, 2020

Yea same here mine is a 6.2 July 2020 USA build with 4,600 miles no issues so far. Occasionally something sounds alil loud at idle but i think it’s possible the high pressure fuel pump under the intake. Only issue I’ve had with mine is after you give it throttle and it drops down a gear it doesn’t like to upshift right away seems to hold that gear to long. Maybe there’s a update?

Edited December 6, 2020 by bjr2020 6.2

BluegrassMotorsport · December 6, 2020

7 hours ago, bjr2020 6.2 said:

Only issue I’ve had with mine is after you give it throttle and it drops down a gear it doesn’t like to upshift right away seems to hold that gear to long. Maybe there’s a update?

I've noticed the same with mine. If I downshift to pass someone or take a "spirited" trip up an on-ramp, seems like it takes it forever to shift down. It likes to hold gears for a pretty long time which for me is less annoying than upshifting too soon - something my K2 with the 6spd was obsessed with.

Edited December 6, 2020 by BluegrassMotorsport

bjr2020 6.2 · December 6, 2020

1 minute ago, BluegrassMotorsport said:

I've noticed the same with mine. If I downshift to pass someone or take a "spirited" trip up an on-ramp, seems like it takes it forever to shift down. It likes to hold gears for a pretty long time which for me is less annoying than upshifting too soon - something my K2 with the 6spd was obsessed with.

I hear you there spot on to what I’m talking about mine doing. Up shifting to quick would be annoying but mine holds the gear for to long when I’m hard on the throttle. I wonder if gm has a update to help? One thing I don’t want is to update and go backwards lol. Thanks for sharing your thoughts too.

DemonWorks · December 7, 2020

I've done the recall on some trucks, it's very interesting, to say the least.

I wouldn't want one of these trucks after the recall was performed ... just my opinion.

It appears that the springs break extremely early in the life and if you make it past a few hundred miles , you are fine.

I have a ZL1 that fell into this recall timeframe and I have made it to 1300 miles so I am assuming my springs are fine.

Tjeli · December 7, 2020

18 hours ago, bjr2020 6.2 said:

I hear you there spot on to what I’m talking about mine doing. Up shifting to quick would be annoying but mine holds the gear for to long when I’m hard on the throttle. I wonder if gm has a update to help? One thing I don’t want is to update and go backwards lol. Thanks for sharing your thoughts too.

This is completely normal behavior. The TCM holds the gear during "spirited" acceleration until it knows what your intentions are. It saves having to upshift and then downshift right away again.

bjr2020 6.2 · December 8, 2020

9 hours ago, Carbon said:

I've done the recall on some trucks, it's very interesting, to say the least.

I wouldn't want one of these trucks after the recall was performed ... just my opinion.

It appears that the springs break extremely early in the life and if you make it past a few hundred miles , you are fine.

I have a ZL1 that fell into this recall timeframe and I have made it to 1300 miles so I am assuming my springs are fine.

That’s wishful thinking I hope your right for both of us. I’ve posted before but my 2015 ltz 6.2 broke one at 59,000 miles sadly. This gen motor appears to be more prone to failures I guess maybe?

bjr2020 6.2 · December 8, 2020

9 hours ago, Tjeli said:

This is completely normal behavior. The TCM holds the gear during "spirited" acceleration until it knows what your intentions are. It saves having to upshift and then downshift right away again.

Is that something they started on these newer T1’s or the 10 speeds? My 2015 6.2 8 speed didn’t do this.

KARNUT · December 8, 2020

So, the computer is trying to anticipate what your intentions are? ( In the old days) my on board computer would manually down shift if needed. Usually the computer is trying to up shift as fast as possible for fuel mileage. As far as possible bad valve springs. Just drive. If they break get them replaced. That’s probably just too obvious.

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Tjeli · December 8, 2020

10 hours ago, bjr2020 6.2 said:

Is that something they started on these newer T1’s or the 10 speeds? My 2015 6.2 8 speed didn’t do this.

I believe this programming is more aggressive in the new 10 speed. Put it in sport mode and drive it hard. It REALLY holds gears then. I have other vehicles with ZF 8 speed transmissions and they both do this as well. They will also use grade logic to decide when to shift. Ever notice it will hold gears longer when you are going up an incline?