‘16 Odd Sound from floor

So my ‘16 Limited that I’ve had over just a year with approx. 60k miles during acceleration has this odd sound that sounds like it’s coming from below my feet. I will confirm rpm tomorrow. It’s also something that only is during the colder weather that can be heard - so it basically just started again as it’s getting colder.

if I had to describe it, it’s sounds like as it’s ramps up on speed/rpm from a stop it leaks exhaust? Like a growl but it’s not mechanical/drivetrain related. I thought it was the BFGs KOs and road noise when I get the rig once it got cold but I’ve since swapped those out for other tires and same thing.

Any of the experienced members hear or know of something similar?


Besides that vehicle drives great, solid no vibrations etc. There appears to be a windshield creek (right above the rear view mirror) that also occurs when cold and driving faster that I’m chasing but that’s for another days story.

 

Not far from your feet area is the crossover pipe for the exhaust. For what you are describing that’s where I would look.

 

My aftermarket armor will sometimes resonate a little at slow speeds. I recall stock armor sometimes made noise if pebbles got in.

 

What do you mean by armor?

 

Skid plates, if you have any.

 

this is a stock limited, so whatever is stock I got for skids.

 

So what @McSpazatron was saying was you might have some loose pebbles or such on top of the stock skid plates, possibly causing the issue. There are a couple of plates under your engine.

 

Yes, that’s what I meant, sorry about not being clear.

Besides an errant pebble bouncing around behind a skidplate, sometimes a bolt might be slightly loose, or there is a missing bolt that allows the skids to resonate. They may even be rusted out, or incorrectly installed in a way that causes them to vibrate. It might be worth checking those out, especially if you’re not the one that does the oil changes on it. Hope you can figure this one out!

 

I do my own changes, just has the skid plate off not even a month ago for a change so I doubt there isn’t anything in there. Are there other skid plates in the area I’m referring to that could be culprit?

Is that cross over pipe bolted somewhere down there or is it a continues piece?

I know the siennas had a TSB on a drone rattle at cold and low rpm due to the fastener loosening up that joins the exhaust pipes together.

yah I’ve had those off and on a few times since ownership for oil changes.

 

There is the front skid that comes off to get at the oil filter, and the one behind it that has the removable door for the oil drain plug. Noise travels in weird ways when it’s a resonance, so the noise isn’t always perfectly traceable to exact location. Did you torque the 4 bolts of the rear skid, or just the oil drain door?

the crossover is a solid exhaust pipe from the drivers side cat until it joins the passenger side pipe behind the cat. It crosses over behind the transfer case. The joint is held together with sprung bolts…they probably dont loosen up if they are not decayed by corrosion. If they’re solid they can take a fair bit of physical abuse without getting loose.

There are some heatshields over the cat on the drivers side. That could make tinny noise if it’s corroded.