[Briannafaith97]

I have a 2012 GMC Acadia that just hit 113k miles. Recently, I have heard a rattle noise almost like if you were to take screws and shake them in an empty plastic bottle. It doesn’t happen every time I accelerate but it usually occurs if the car hasn’t been driven in a day or two. No check engine lights or any other signs of what it could be. It happens from a complete stop and eventually goes away after a few seconds. Any ideas?

 

[JayTee2019]

I have a 2012 GMC Acadia that just hit 113k miles. Recently, I have heard a rattle noise almost like if you were to take screws and shake them in an empty plastic bottle. It doesn’t happen every time I accelerate but it usually occurs if the car hasn’t been driven in a day or two. No check engine lights or any other signs of what it could be. It happens from a complete stop and eventually goes away after a few seconds. Any ideas?

Take it to one of those chain auto supply stores or call several and see if they will do a free scan of any pending pr permanent engine codes.
To me, off had without hearing it, I'd say it may be engine knock which could have several causes like timing is off or even carbon build up in the upper cylinder and piston tops.
If the later, you could try some high PEA gasoline additive in a tank or two at fill up and then run each down to near empty. That may help. I would go with something like Gumout On-N-Done which has a high PEA content and is the stuff that works to clean engine deposits.

But for sure, take the Acadia in and have codes read maybe even by a good shop.

 

[speleos]

... It happens from a complete stop and eventually goes away after a few seconds. Any ideas?

Could be a loose heat shield.

 

[Briannafaith97]

I drove it today fully warmed up and didn’t hear the rattle once so I think it may be the heat shield after some research. I’m going to take a look underneath and see if it looks loose or damaged

timing chain I would hear just about every time, correct?

 

[JayTee2019]

I drove it today fully warmed up and didn’t hear the rattle once so I think it may be the heat shield after some research. I’m going to take a look underneath and see if it looks loose or damaged

timing chain I would hear just about every time, correct?

Yes. . . and would not usually occur every time or only when you accelerate .

 

[Briannafaith97]

Well heat shield is definitely cheaper than timing chain so I’m hoping that’s my fix, lol. I only noticed it about a month or two ago and it occurred randomly so it had me stumped

 

[JayTee2019]

Well heat shield is definitely cheaper than timing chain so I’m hoping that’s my fix, lol. I only noticed it about a month or two ago and it occurred randomly so it had me stumped

Yeah, those heat shields can get damaged from rust or loose mounting bolts and even having been removed, bent and reinstalled too many times for service work. Usually the ones that are around or near the exhaust manifolds get that way. Sometimes the bolt holes get rusted and the "tabs" with the holes in them just disappear. LOL

 

[Grantv]

Yeah, those heat shields can get damaged from rust or loose mounting bolts and even having been removed, bent and reinstalled too many times for service work. Usually the ones that are around or near the exhaust manifolds get that way. Sometimes the bolt holes get rusted and the "tabs" with the holes in them just disappear. LOL

In the many years we owned my wife's Rogue, I now recall one thing did go wrong with it; a rusted muffler heat shield clamp in exactly that location.
2014, bought it in '17 IIRC, traded it in a couple months ago. Not much prior there was a rattle under the car, mostly just under acceleration. First thought of... a heat shield. Get it up on ramps, yep, there she is. $4 later for a muffler clamp, 5 minutes of work, she good.

 

[J.Brasi]

I thought I was the only one with that same problem I've been looking for post's with the same issue. I have a 2016 Acadia, the engine always been taken care of every 3000 mile oil change Valvoline with Lucas, 3 transmission flushes also Valvoline w/lucas every 30,000 miles, new spark plugs, and all fluids have been flushed and filled with new, full tank of gas with lucas injector cleaner or lucas octane booster every Friday, and of course cold air intake filter always cleaned. It has been running great with no problems luckily since I see all these different problems everyone been having
but recently if I'm coming to a complete stop and slowly take off you can hear a vibration/ rattle like a dust plate or heat shield is loose but it doesn't always happen. I have OTC scanner but no codes I asked a buddy of mine who's a mechanic and he thinks it might be the flywheel getting loose. So that's my next step since I do my own labor.

 

[JayTee2019]

- - - - cell phone post. Too many run on sentences really, if you want most people to read and communicate back. Just sayin'.
And. . yes. . using too much Lucas. More is not always better plus it is costly. . . IMO

 

[Grantv]

I thought I was the only one with that same problem I've been looking for post's with the same issue. I have a 2016 Acadia, the engine always been taken care of every 3000 mile oil change Valvoline with Lucas, 3 transmission flushes also Valvoline w/lucas every 30,000 miles, new spark plugs, and all fluids have been flushed and filled with new, full tank of gas with lucas injector cleaner or lucas octane booster every Friday, and of course cold air intake filter always cleaned. It has been running great with no problems luckily since I see all these different problems everyone been having
but recently if I'm coming to a complete stop and slowly take off you can hear a vibration/ rattle like a dust plate or heat shield is loose but it doesn't always happen. I have OTC scanner but no codes I asked a buddy of mine who's a mechanic and he thinks it might be the flywheel getting loose. So that's my next step since I do my own labor.

Well first, I'd look for a loose anything under the car. Get it up on ramps, look and feel all along the exhaust and anything in the area for anything loose. Then have someone get in and rev the motor lightly at the RPM's you think you hear it. Then stop using Lucas additives every 5 minutes. OK, you can do the latter if you wish I guess... (although I wouldn't)

 

[divotdug]

Sounds like they need some Lucas flywheel tightener

 

[speleos]

Sounds like they need some Lucas flywheel tightener

Does Lucas sell VtT punctuation marks and sentence shortener, too?

 

[J.Brasi]

My bad I should've mentioned that I get Lucas products for free. But your right I should stop using Lucas since this is my first problem with 110,000 miles that for the tip. But fixed it already, all it needed was a new tampon your box rattling stopped immediately..thanks good looking out. I remember to ask you first for next problem👍

 

[Grantv]

...But fixed it already, all it needed was a new tampon your box rattling stopped immediately..thanks good looking out. I remember to ask you first for next problem👍

Uh, glad it got fixed...

 

[J.Brasi]

Thanks, Appreciate it bro. All I'm saying is all you have to do is ask and tell me where to send you some free Lucas products. Don't get mad just because of what I use. In other words don't hate, participate and I got you

 

[Grantv]

Nobody hating. Just saying I'm not really a believer of additives unless something calls for it.

 

[JayTee2019]

Yeah .. . can't do anything about someone who wants to put it on everyone else and label them a hater.

 

[Briannafaith97]

Definitely a loose heat shield. It was barely hanging on. Thanks for the help! It’s fixed and no rattle.

 

[Grantv]

Definitely a loose heat shield. It was barely hanging on. Thanks for the help! It’s fixed and no rattle.

That's great! We were a bit worried about my wife's Rogue, as we were about to trade it in. Having a 5 minute fix is a big relief.