Any rattling noise issues when accelerating in your Hyundai?

Hey guys, so my 2009 Sonata V6 has started making this weird rattling noise near the engine when I step on the gas. It’s only happening when the car’s in drive, not in Neutral or Park. Any idea what could be causing this?

Appreciate the help!


I’ve got a 2009 Sonata too, and I’ve been dealing with that same annoying rattle when I accelerate. My hunch is it might be a loose plate in the catalytic converter or muffler. Since it was a used car with low mileage, there could’ve been a lot of water in the exhaust. I’ve tried banging on the exhaust pipes to see if I can pinpoint the sound, but no luck so far.

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Yeah, I’m dealing with that too on my 2009 V6. Took it to the dealer recently for an oil change, and they thought it might be the heat shields rattling, but they checked and said everything was tight.

Then they suggested it could be the baffles in one of the mufflers, but that turned out to be a dead end too. Now I’m thinking it might be the flex pipe somehow. It’s weird because the noise comes and goes, and it’s more noticeable when I’m going uphill. I’ve been trying to track it down, but no luck yet.

There are a few possible reasons why your 2009 Sonata V6 is rattling:

  1. Look for any loose elements in the exhaust system.
  2. Engine Mounts: When driving, noisy mounts could be the result.
  3. Low fluid levels or malfunctioning parts may cause transmission issues.
  4. Check for wear or damage on belts and pulleys.

For a precise diagnosis, a mechanic’s inspection is advised.

The flex pipe or another exhaust part can be the problem. A problem that changes with engine load may be the cause of intermittent noises that get worse uphill. Proceed with your exhaust area investigation and get a second opinion.

I’m having the same noise as you Flippa described, sounds like chittering between 1.5-2k rpm, I had the car looked at and nothing at all was found… Even by Scanning, I hard to take it to my mechanic to look at it

I understand your frustration with the annoying Sonata rattle. Dealing with vehicle noises can be vexing. Your hypothesis about a loose catalytic or muffler component is reasonable. Water in the used low-mileage exhaust is a plausible factor. Banging on the pipes to locate the rattle is a good troubleshooting step, though it hasn’t worked. I hope you resolve the issue soon.

Hey there!

I can certainly understand your frustration with the strange rattling noise in your 2009 Sonata V6.

Possible causes include loose engine/transmission mounts, worn exhaust components, or issues with the drivetrain.

I’d recommend having a mechanic inspect it to isolate the source.