Brandon_210TX
New member
Just recently I’ve started to here a slight metallic rattle/clinking when slowing down. Doesn’t happen when accelerating but happens when slowing down just before coming to a complete stop. Anyone else having this issue?
21 AT4- Metallic clinking/ rattling noise when slowing down….
- Thread starter Brandon_210TX
- Start date
Yes, I’ve had the same thing and noticed it starting right around 5,000 or so miles. I’m at 6,700 now and it’s still doing it. As odd as it may sound, if it is the dreaded lifter issue I’d rather it happen sooner than later so I can get it fixed under warranty.
Fightnfire
Member
I've experienced an issue, noise, like this. Not only coming to a stop but also when maintaining speed with very little accelerator pressure, minimal RPM. I've had it in for the dealer to diagnose and no luck.
Brandon_210TX
New member
On the way home again, almost between 11 mph and 20mph while slowing down, there it was again. As if someone dropped the tiniest screws in a metal cannister and shook it for a split second. I think I’ll wait till my first service to bring it up at the service department. At 2.5k miles ….still brand new…. Just annoying. @Bblack almost in the same boat…..with it being still under warranty. @debo4x4 worth a try but don’t think that’s a lasting solution.
I hear you. I’m not one to buy extended warranties usually but I did buy one for this truck considering it was a $60+ purchase. If I use it once it will pay for its self. Actually taking it in today because I got a “service 4WD” message when I put it in auto when the roads were slick. The drive train indicator turned from white to orange as it went into auto. It seemed to still work as I tested it by putting my foot into it a couple times at a stop light. Still, shouldn’t have a service message with 6700 miles on it. Going to have the dealer look at that tic too. I’ll post what they have to say about it but assume if there is no misfire error it’s not a lifter. @debo4x4 - I’ve had it in L9 a couple times and I do notice less tick at slower speeds however I figure if the lifters go bad I’d rather have them replaced sooner rather than later and drive the truck like it’s meant to be driven.
Brandon_210TX
New member
Any news/word on the clinking or what was wrong with your 4wd message from the service department?
The dealer said the engine was fine, normal even. The service 4WD was because a rodent they say chewed on a wire that caused the service message. I live near orange groves here is Florida and it’s not uncommon for fruit rats or mice to chew on electrical wires. Not under warranty but was a cheap fix.
Gabed23AT4
New member
Curious if you’ve had any new developments or worsening of symptoms?
I have a 2021 AT4 that has a vibration or grinding sound very noticeable especially when slowing down or under 18 MPH.
Local dealer inspected & claims all normal?
chaos
Member
I've got what sounds to be similar. 3600 miles. There's a article on gm-techlink about a shudder condition when coasting to a stop. Mine is most noticeable on decel from about 18 to 13 MPH.
Link to article published Sept 2021 with some details - https://gm-techlink.com/?p=15387
I have the dealer flash the ECU when I take it in for first service at around 5k. Hopefully it'll fix it. If nothing else, it'll be documented as a complaint and that way when I complain again they'll see it wasn't fixed the first time.
Link to article published Sept 2021 with some details - https://gm-techlink.com/?p=15387
I have the dealer flash the ECU when I take it in for first service at around 5k. Hopefully it'll fix it. If nothing else, it'll be documented as a complaint and that way when I complain again they'll see it wasn't fixed the first time.
Pb82 Ronin
Well-known member
Subbing. Curious myself.
MGoodwin19AT4
New member
I have the same annoying shudder when coasting to a stop. My wife thought I was crazy. It absolutely has something to do with the DFM. When i drive in L9 the shudder goes away. Thinking of taking mine into the dealer based on the info in the link you provided but wish i didn't have to remove my catch can and intake to do so.
chaos
Member
I'm in the same exact boat. Have to pull my catch can when I take it in for service. Probably the worst part of owning the catch can.
Someone on another thread said with the upgraded intake, you don't have to pull the intake and it's all right there easy to get to. I'm tempted to order the upgraded intake just to make it easier to pull the catch can hoses for service when required.
MGoodwin19AT4
New member
I just put an S&B intake on and It is much easier to access the catch can hoses. My only worry is the dealer trying to tell me the issues with the shudder are a result of the aftermarket intake.
chaos
Member
I guess that's a benefit of running the GMC performance intake - they can't claim it's the intake's fault then. I'm a mechanical engineer and the incompetence of dealer service managers and techs is sometimes scary. If you are lucky, there may be one guy who knows what he's doing, but otherwise all they know is how to change tires and do oil changes.
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