Groaning Sound at First Start (1 Viewer)

[Colin Yankee]

Looking for some help with a new issue (video attached). After sitting for a few hours, my 2019 LC200 has a groaning sound with some vibration that seems to come from behind the center console when it first starts up. After that initial start, the sound goes away. If I shut it off and restart it, it doesn’t make the sound again . . . it only makes the sound after sitting for a bit. I am in Tennessee, so it isn’t extremely cold. Battery checks out, it drives normal and I haven’t picked up on any other issues. Only new thing in the vehicle is a new wire passing through the driver side firewall grommet for the Dometic DC hardwire kit. That wire is connected to my second battery with a Redarc BCDC. The sound doesn’t do it justice, but you can hear the difference between the initial start and the second start in the video. Thanks for any insight!

 

[Colin Yankee]

Video Link
Link to video

 

[bloc]

FYI no video..

Maybe see whether it’s related to the cold air injection pumps located in front of the passenger front tire.. possible a resonance is going through the chassis?

Normally I’d guess the nav unit fans for a center console groan but personally that sounds very unlikely on something as new as a 19.

 

[Colin Yankee]

FYI no video..

Maybe see whether it’s related to the cold air injection pumps located in front of the passenger front tire.. possible a resonance is going through the chassis?

Normally I’d guess the nav unit fans for a center console groan but personally that sounds very unlikely on something as new as a 19.

Thanks. Having some trouble getting the video to upload

 

[bloc]

The short, loud sound? Strongly reminds me of an ABS module activation. It is built into the brake master cylinder and can vibrate the firewall. There aren’t any motors or things large enough to make a sound like that within the console. And my initial mention of cold start injection pumps.. definitely not.

If you have any helpers available, try it again with a hand placed on the brake master cylinder in the engine bay. If you feel vibration there.. it’s something going on. To my knowledge that wouldn’t be part of the usual start up procedure. Find someone with techstream or an advanced code reader to see whether there are any codes stored within ABS/VSC system.

 

[Colin Yankee]

I "solved" this shortly after posting it . . . but wanted to close it out in the forum. When I got a helper to start it after sitting, I was able to figure out where the groaning/vibration was coming from. Well, in an embarrassing, but also relieving, moment, I realized it was my ARB compressor. It is under the hood, and so is the switch. I had left it on, so every time it would sit for a period of time and then the vehicle was started, it would fire up briefly. I flipped the switch off, and no more noise. Silly, I know, but glad it wasn't something more serious.