Hello all. New member here looking for some insight. I have a 2016 Stingray 3LT convertible that we have owned for a few years. Last year we noticed a "rattling" sound when the car was lugging. Doesnt matter if its at highway speed or just running around town. If the car is lugging at low RPM, it seems to make the noise. I had the dealer look at it and they could not pinpoint the source of the noise. They ended up not charging me any diagnostic time as they couldnt find it which was great... but bad news is i still have the noise. I have attached a video in the hopes that someone out there has had some sort of a similar issue and can point me in the right direction. You have to turn the sound up to hear it, but it starts about the 3.5 second mark.

 

I can't hear it, but it may be my computer, it's old.

 

I couldn't hear it, either.

 

Couldn't hear it either. Maybe move your phone around different areas of the car to see if it can be picked up any better

 

How about on this one....I can hear it better in this one, but i also know what i'm listening for. Sounds like a rattle. In this video its almost through the entire length of the video

 

Wierd part is it seems to not occur if you drive in manual shift mode rather than automatic, which doesnt make a lot of sense i know

 

We have the same set up - 2016 Z51 Convert. Have (had?) a noise like a riff shuffle of playing cards. Never in all V8 mode - in other words using the "M" mode. Only heard when car seemed to just enter V4, and only hear noise for small time intervals during transition. Applies to a 2014 tech bulletin which blamed the tensioner. It seems they (GM) thought the belt was singing like a guitar string when the load on the engine changed. We JUST had the tensioner replaced and will report if the noise is gone. Tensioner had an oil ring around the seal and the belt looked OK. Some guys say the belts can have a cord loose on the belt edge which makes a flutter noise also. Whatever the cause, the fact that we never hear it when in all v8 mode seems a pretty clear clue if you try to run it down. We promise to report in a week or two as to whether the tensioner fixed it. Again, key noise is like a deck of cards riffleing, transient and never in V8 mode.
BTW, tech bulletin mentions horsing around with the exhaust "flapper" valves and the control system for that feature. Seemed like a lot of screwing around to me.

 

That is great feedback and that would make sense if it is only in v4 mode. The noise can be occuring and if you drop transmission into manual mode it goes away. My car doesnt have the exhaust valves at the tailpipe (if those are the ones you are referring to) so I guess it shouldnt be those. Do you happen to have the part numbers they replaced in your vette? I'll go ahead and get mine replaced (or maybe it would be cheaper to buy a programmer and just tune out the v4 mode )

Thanks again

 

Keep in mind I haven't yet confirmed the tensioner fixed the noise. The part number was: 12686272 (S), now, this may be the belt number, as the bill may have left off one of the part numbers, or listed it somewhere else. We haven't taken a car in nearly ever, as I do my own work, so reading a modern repair bill is confusing. The belt number may be: 12651112 (S)

 

So given the similiarity to my situation, i went ahead and ordered Genuine GM replacements from Rock Auto. Got them installed tonight and whether or not it fixes the noise, that tensioner was definitely an issue or about to be an issue. I replaced it and took the car for a quick spin and i couldnt reproduce the noise so here's hoping it fixed the issue. I'll drive it a little further tomorrow so should know for sure if that was the culprit.

 

You can see in the above video, the one bushing is completely gone....

 

Whether that fixes the noise or not, that was definitely in need of replacement. Don't think I've seen one that bad on here before