03-21-2017, 12:36 PM | #1 |
Drives: 2019 GMC Sierra 1500 AT4 Join Date: Nov 2011
Location: Orange, TX
Posts: 740
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Surging at high RPMs
My car is a 2017 2SS M6. 100% stock, no performance mods.
I've noticed at high RPMs and WOT it surges 1-2 times. Usually at around 5200 and 6000 or so RPMs. This happens in 2nd and 3rd every single time at those RPMs and WOT. It almost feels like pulled timing, but it's very short duration (fractions of a second) and the power comes right back. When it does it in first gear I assume its due to traction control since that light pops up every once in a while. I highly doubt traction is the issue in 2nd gear, and no way the tires are getting loose in 3rd on a straight and 80* temps. It does it in tour, sport, and track modes regardless of whether ARM is enabled. Anyone else notice this? I really dread having to bring it to the dealer and have some random tech beat on it to replicate the conditions.
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2019 GMC Sierra 1500 AT4
Summit White 6" Lift, 37x13.50R24's |
03-21-2017, 01:02 PM | #2 |
マスタング = 遅い
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I assume you have tried this with traction control off, and it does the same thing?
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03-21-2017, 02:30 PM | #3 |
Markoon13
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The dealer isn't going to beat on it lol. They will probably just plug in a computer and try to diagnose the problem. I would go
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03-21-2017, 02:33 PM | #4 |
Drives: 2SS & GT Premium Join Date: Jan 2017
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Going by this statement I am lead to believe you haven't tried turning off the TC yet? I mean that can't be possible, as I am sure you would do that before asking on a forum...
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03-21-2017, 03:25 PM | #5 | |
Drives: 2019 GMC Sierra 1500 AT4 Join Date: Nov 2011
Location: Orange, TX
Posts: 740
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Quote:
I'll give that a try. Don't know why it didn't occur to me to try that already.
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2019 GMC Sierra 1500 AT4
Summit White 6" Lift, 37x13.50R24's |
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03-21-2017, 04:31 PM | #6 | |
Drives: 2019 GMC Sierra 1500 AT4 Join Date: Nov 2011
Location: Orange, TX
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Quote:
Same thing regardless of traction control, stability control, competitive mode, or all fully off. 93 octane gas from 2 different stations so doubtful it's bad gas. Guess I'll bring it up to the dealer since no one has chimed in saying it's normal.
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2019 GMC Sierra 1500 AT4
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03-21-2017, 08:01 PM | #7 |
Drives: 1969 Mustang MaCh1 Join Date: Nov 2015
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As an alternative, you could throw it on a dyno to see if power really changes at those RPM's. Could be pulling timing on some false knock, It would be obvious on a dyno. On top of it, you'll get a nice baseline dyno sheet.
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03-21-2017, 09:03 PM | #8 |
Drives: 2019 GMC Sierra 1500 AT4 Join Date: Nov 2011
Location: Orange, TX
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Both the tach and speedometer hang a bit during these surges.
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2019 GMC Sierra 1500 AT4
Summit White 6" Lift, 37x13.50R24's |
03-21-2017, 09:04 PM | #9 | |
Drives: 2019 GMC Sierra 1500 AT4 Join Date: Nov 2011
Location: Orange, TX
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Quote:
Thanks. Great advise.
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2019 GMC Sierra 1500 AT4
Summit White 6" Lift, 37x13.50R24's |
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04-04-2017, 08:30 AM | #10 |
Drives: 2019 GMC Sierra 1500 AT4 Join Date: Nov 2011
Location: Orange, TX
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Update on this. The problem seems likely to be related.
Got a CEL. Onstar said "variable valve timing problem" when they read the code. Car bucks and surges at all RPMs during acceleration and constant speed driving. Almost feels like a big cam with a bad tune. Dropped it off at the dealer this morning. Will post the resolution when I find out. Sent from my iPhone using Tapatalk
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2019 GMC Sierra 1500 AT4
Summit White 6" Lift, 37x13.50R24's |
04-04-2017, 09:14 AM | #11 | |
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04-04-2017, 03:57 PM | #12 | |
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04-04-2017, 05:16 PM | #13 |
Drives: 2019 GMC Sierra 1500 AT4 Join Date: Nov 2011
Location: Orange, TX
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Yep. Phone call from the service department this afternoon. "Sorry we didn't have time to look at it today. Hopefully we can get to it tomorrow, but we're booked solid to Thursday. We're very sorry that you're without a ride to and from work. After we diagnose the problem, and if GM approves, we can put you in a rental for $38/day. Until that happens we have shuttle that can take you to and from the dealership." I'm pretty far from happy about it. Is this the normal warranty repair experience?
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2019 GMC Sierra 1500 AT4
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04-04-2017, 05:37 PM | #14 | |
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