Click and “Puff” Noise on Engine Shutdown

[jlglr4]

Wondering if anyone can shed some light on what causes this noise in the SCV6 engine, and whether it’s normal: About 5 seconds after shutting off the engine, there is a click followed by what sounds like a puff of air. In the attached short video, the click is heard at about 8 seconds, but the “puff” sound is not picked up. Sounds like pressure being released, or something under tension being decoupled. It seems to be coming from the area of the supercharger, but tough to tell for sure. I mentioned it to the dealer on the last visit, and the technician came out and listened - thought it was normal and that it was a computer controlled actuator of some kind, but didn’t know exactly what actuator.

The only fault code I’m seeing is U0241-00 (2C) “Lost communication with the headlamp control module A“ which I assumed to be unrelated, but now I’m wondering if the sound could be from the adaptive headlight control.

Any advice appreciated.

 

[Strizzo]

Mine makes the same noise, and I also had the headlight lost communication code, however my adaptive headlights work fine and I didn’t have it the previous time I scanned for codes so I figured it was just a random code.

when I shut the truck off and get out it usually makes a few self leveling adjustments right after I lock the doors

 

[TrinidadLR4]

Might be air suspension leveling itself. Mine does this too.

Sent from my HD1905 using Tapatalk

 

[scott schmerge]

Air suspension. Totally normal operation

 

[jlglr4]

Thanks for everyone's input. I'm quite sure it's not the air suspension I'm hearing. My air suspension levels after shutting off the ignition, but that's a completely different sound - more of a distinct hissing of air. The sound I'm talking about is more of a thud or "puff" sound - no hissing. I'll try to get a better sound file.

 

[pluckerman]

I'm curious about this as well. Did you ever figure it out?

 

[jlglr4]

I think its just the throttle body shutting down. I just never noticed it so much in other cars I’ve had.

 

[DallasLoneStar]

My ram 1500 has a crazy amount of noises if I turn it off and stay inside. Its all the HVAC ducts closing up. Perhaps it may be something related to that?

I have heard the hiss in the LR4 after shutting down and figured it was the air suspension leveling after my fat rear end got out of the truck haha.

 

[jlglr4]

Yeah, the air suspension releases some air after passengers exit. This is different. About 3 seconds after shut down, just a mechanical click accompanied by a kind of a thud or “puff” noise. Pretty sure it’s the throttle body. Definitely not the suspension or HVAC.