Can be heard under the hood and in the cabin. My buddy and I swore it was the tensioner pulley because it sounded like it was coming from that area, but I changed it, and it was still there.

There seems to be no rhyme or reason...idle, neutral, parked, a/c on or fan, fan on or off. Car runs great, no codes, no leaking fluids. I cannot track it down and haven't seemed to come across it on the forums yet.

It is faint in the videos, but it's there, headphones might work best.

Too large to attach, link below to google drive:
1) https://drive.google.com/open?id=1pH...RZ-3wKIKn-MGJa
2) https://drive.google.com/open?id=1oY...gnWWIudslWEKZ5

Thanks!

 

Really tough to make out in the videos. Are you able to get audio from under the hood, and possibly better pinpoint where it's originating?

 

It’s even harder to get audio under the hood with all of the accessory sounds. Like I said, at first glance it sounded like it was coming from the tensioner pulley area. So much so that I replaced it.

I’ve been under the hood with a mechanics stethoscope and just can’t pinpoint it. It’s so sporadic by the time I hop out of the car it’s not doing it.

 

What is the cadence like? High frequency rattle or more of a ticking sound? One item that is somewhat common for your age/mileage is wear in the turbo actuator bolt. That would be a rattling sound when letting off the throttle that isn't noticeable at idle or under normal driving/cruising. Eventually a code is thrown, but in my case I noticed the noise for quite some time before my check engine light actually came on. But again, with the videos so far it's just really difficult to make anything out for certain.

 

its sounds like a gruunnnt, is that it?
like the sound of an old engine when you shut off and doesnt right away. is that it?

 

I can’t hear anything in that video...check the compressor/clutch assembly that might be on its way out. Then check the catalytic converters heat shield for rusting/missing bolts.

 

To close the loop on this, anyone who has a strange rattling, knocking, noise coming from the dash area; listen to the video, full volume, with earbuds in, you will hear it.

I recently took the 'ol girl in for a valve lash adjustment and new plugs and now the noise is gone. Correlation versus causation. Did the work fix it, or did he do something else while he was in there???

Either way, do this service! Holy smokes! Car has 105k miles and feels brand new. I am amazed at the difference it has made. Idle, sound, power delivery, everything.