Help: What's something that spins only when moving AND supplying gas?

WestCoastWagon · Post by **WestCoastWagon** » 17 Dec 2023, 19:02

Hi all,

I'm looking for assistance diagnosing a noise coming form the engine bay:

It's a cyclical "chh-chh-chh" noise that only appears with foot on the gas while moving (it doesn't happen when revving in Park or Neutral at a standstill) and it doesn't disappears when coasting. Its frequency increases with speed. It seems to go away at higher speeds, but it may just blend into a constant noise with the rest of the normal car noises. No noticeable performance issues.

My problem is I can't find the source because it only occurs while moving (with foot on the gas)...

Any leads would be appreciated!

Thanks all.

Post by **chrism** » 17 Dec 2023, 19:24

It could possibly be an exhaust leak, like a manifold gasket or turbocharger connection, etc.
Can you duplicate the noise when at a stand-still by firmly holding the brake pedal down, putting it in gear, and giving it some throttle? (Increasing engine load)

Post by **jonesg** » 18 Dec 2023, 04:14

in mine it was a bent dust guard behind the brake disk.
i found it by putting the front wheels on jackstands, disabling the rear by removing the haldex fuse, start engine, put in drive and let the wheels spin. if its in the drivetrain you should be able to track it down.

Post by **volvolugnut** » 18 Dec 2023, 07:53

jonesg wrote: 18 Dec 2023, 04:14 in mine it was a bent dust guard behind the brake disk.
i found it by putting the front wheels on jackstands, disabling the rear by removing the haldex fuse, start engine, put in drive and let the wheels spin. if its in the drivetrain you should be able to track it down.

This is good method to trace the noise.
volvolugnut