Loping sound at warm idle - 2014 Acura TSX K24

[cammyfive79]

I've noticed this for a couple of months at least and the car drives great with good power and fuel economy but this sound at idle doesn't seem normal to me or I have not noticed it in the previous two TSXs of the same generation. I would try to describe it as a wompwompwompwomp sound in the background. I only hear it after driving the car for a while and its up to full operating temperature and I've come to a full stop. I've tried putting it in park, reverse, neutral, and drive, as long as I'm stopped it's there. I don't feel any excessive vibration at idle and rpms hold consistent in the 700-ish range.

Car has very low miles (30K) being 10 years old so I did all of the usual stuff due to age - filters, fluids, pcv vavle, plugs, etc. No idea what is causing this sound. The "clatter" at the forefront sound is normal for this engines, but not the backround womp-womp sound. Video was recorded in the pharmacy drive thru that hopefully catches the sound.

 

[michaelluscher]

Belt tensioner or pulley?

 

[cammyfive79]

Good thought. Recently had just the drive belt replaced and I noticed it before then too. How would I go about doing a cursory check to see if it's either the tensioner or pulley?

 

[LWood]

You can open the hood and look down and see if the belt seems to be running true as in no wobble etc,not familiar with your engine but perhaps you can see if the tensioner is pulsing.
Of course as always when close to a running engine be mindful of your hands and loose clothing for safety sake.
That being said, to my old ears it sounds like an exhaust sound, possibly a blown manifold gasket or the exhaust pipe is partially disconnected. It's always difficult to diagnose by video sound.
Larry

 

[Ownster]

I've noticed this for a couple of months at least and the car drives great with good power and fuel economy but this sound at idle doesn't seem normal to me or I have not noticed it in the previous two TSXs of the same generation. I would try to describe it as a wompwompwompwomp sound in the background. I only hear it after driving the car for a while and its up to full operating temperature and I've come to a full stop. I've tried putting it in park, reverse, neutral, and drive, as long as I'm stopped it's there. I don't feel any excessive vibration at idle and rpms hold consistent in the 700-ish range.

Car has very low miles (30K) being 10 years old so I did all of the usual stuff due to age - filters, fluids, pcv vavle, plugs, etc. No idea what is causing this sound. The "clatter" at the forefront sound is normal for this engines, but not the backround womp-womp sound. Video was recorded in the pharmacy drive thru that hopefully catches the sound.

It's more than likely the tensioner on the belt going out, common issue on honda of all makes that use one.

 

[cammyfive79]

It's more than likely the tensioner on the belt going out, common issue on honda of all makes that use one.

Thanks. I actually watched a couple of youtube vidoes on that issue last night so I'll try to check it out today.

 

[melk]

Does the noise change in relation to throttle?

 

[cammyfive79]

Does the noise change in relation to throttle?

With any application of throttle I can no longer hear it. Doesn't mean it's not there, its that the normal noise of the engine overshadows it.