I completely understand that it's impossible to diagnose the issue with limited knowledge and no recording of the noise, but since I'm completely lost - maybe someone can give at least an educated guess.

My GS F (2018) was parked on the 4th floor of a parking garage for roughly 4 days. It's on the 4th floor because it's pretty much always empty, and I don't have to worry about someone dinging it with the door. When I started the car, I heard some loud noise outside, initially I thought it's some construction or something else, but when I stepped out from the car I quickly realized that it's coming from my car. I jumped in, turned the engine off - noise stopped. I popped the hood, and started the car again, and it still made that noise which sounded like when a paper gets stuck in the vacuum or something like (but much louder). I looked at the dash - no error messages, jumped out and once I reached the front of the car - it stopped. Drove the car for ~5km, no issues, no lights... inspected the engine compartment - everything seemed OK.

Car feels fine atm, but I'm trying to figure out what might have caused it, and whether it means that something is wrong with the car (or if whatever that caused that sound might have damaged the car).

The (unlikely) things I thought about:
1) Loose hose or smth - doesn't make sense since drove fine when I parked it and not something that would fix itself?
2) Some rodent got in the engine compartment, and either jammed something with seeds/**** or got itself stuck somewhere
3) Someone tampered with the car

I would appreciate any guess, no matter how wild. Thanks.

 

Paper stuck in a vaccum? You mean like a cold start? Idk man, youtube GSF cold start to see if that's the sound you're referring to.

 

It's hard to describe the noise, and I can't believe that there is a video on YouTube about a paper stuck in the vacuum, but:


It's pretty close to the sound...

 

Yesterday I heard what sounded like a pop followed by what sounded like a tin can full of pennies being rattled about. Freaked me out. Turns out that my wife was doing some gardening and left a pile of debris on the edge of the driveway that meets up my garage. There's about a 1 inch cracked where they meet that got filled w dry leaves and crap she failed to clean up. The noises ended up being that crap vibrating due my exhaust. 100% sounded like the vacuum/ paper description. Blew the crack out w the leaf blower and is well. If you can't duplicate the sound or find anything wrong I'd bet something was lingering on the ground out back and when you started your car. And......in a parking garage the sound would be more intense w all the echoe effects a garage induce.

 

There is a module for the braking system near the booster that can make some noise at first-almost sounds like a compressor. It’s completely normal.

Steve

 

What conditions cause this? I've never heard it on either of the F cars in normal operation, but I can simulate it with Techstream by actuating the ABS motor and valves.

 

Great question. I'm not sure. I don't hear it on the GS-F, but I have heard it on the wife's Land Cruiser. I need to look at the manual for that vehicle.


Steve

 

lol.....it's safe to say that the land cruiser has nothing to do w the GSF.

 

Looking at the braking system, they look like they both have that module.

Steve

 

Could be low pressure fuel pump. Record the noise with your phone and post it here.

 

Just wanted to update that I've had longer commutes after it and have really pushed the car hard without any problems nor any similar issues... guess it was something environmental like Jerry suggested.