My step dad bought a 2018 Colorado diesel a little over a year ago which he loves, but I was in it a few weeks ago and noticed an odd noise when the truck is stopped in gear (like at a stop light). It sort of sounds like something vibrating under the truck or in the engine compartment but not exactly. It’s kind of hard to describe, but it does not sound normal. As soon as you let off the brake or put the transmission in neutral, the noise stops. Has anyone else experienced any similar noises? He asked the dealership to look into it, and of course, they were of no help. I’m going to see if I can find anything, but I’m hoping maybe someone has dealt with this before and can point me in a direction on where to look. Thanks guys!
Strange noise at idle in gear
- Thread starter JoshH
- Start date
It’s tough to describe, and it’s been a while since I heard it. From what I recall, it’s sort of a hollow thumping sound with a slight metallic rattle to it. I’ll try to get a video and peek around for something obvious.
My brothers lml has a similar noise. Could have swore it was a heat shield, but it is the belt. It only happens at idle in drive. New belt and tensioner and it still does it. It’s just loud enough to be crazy annoying.
Based on that, Dylan, could it possibly be a pulley out of alignment, like how we used to have to deal with the PS pulleys back on the LB7s?
It didn’t look like it at a quick glance. The belt is “wagging” and making a vibration noise. I can just set my finger on it and it stops. We haven’t looked too closely at it.
i wasnt even going to attempt to make those noises over the phone :roflmao:
what year and how many miles on it Luke?
my 2020 hasnt made any weird noises other than what sounds like a bbq igniter going off every sec or so in the exhaust under the cab.
I have a 2018 canyon with the 2.8l and I have had a similar thumping noise and vibration intermitenly. It's more pronounced in reverese but I can also feel and hear it in drive. In park it pretty much goes away.The vibration feels like its coming from right under the driver side floor board. I'd really like to figure this out aswell. Its been to the dealer twice but it acts up while they have it. This is on my 2018 canyon with the 2.8L duramax.
I did a little more digging into it yesterday trying to find the source, and I took a short video that I uploaded to youtube. The noise goes away as soon as you put the trans in neutral or raise the RPM slightly (you can hear it come and go in the video). In the video you can hear it go away as soon as he gives it just a little throttle. The noise is actually a lot louder than it sounds in the video, but I couldn't hear it outside the cab over the engine noise. I felt around the back of the motor trying to find something rubbing, but I had no luck. We also put the trans in reverse, and we couldn't hear it. It seems to only make the noise while in drive. No comments about my white legs! 
:rofl:
[youtube]IYch99tKwDY[/youtube]
:rofl:[youtube]IYch99tKwDY[/youtube]