Tried searching but not sure I've read anything about my issue. I bought my 2024 4Runner new and it's almost a year old. I parked in the garage and was standing beside the 4Runner about 5 minutes later when the truck started sounding like someone was releasing air from a balloon that had been blown up really tight. It was a high pitched sound that went up and down somewhat for a few seconds. I'm thinking it was from the engine bay but not 100% sure. I've owned multiple 4Runners and never heard this before. It's not the evap sound you hear several hours later. This was 5 to 8 minutes after cutting the truck off. I cranked it back up then cut it off to see if I could duplicate it but no luck. And suggestions?

I believe I've had my 2023 do the same thing on a few occasions. I figured it was some electrical or other system that just does its stuff on occasion.

It's probably the fuel/EVAP system, perfectly normal. It's mentioned in the manual.

Thanks for the reply but it's not the evap. The evap cycles 5 hours after shutting the engine off and I'm very familiar with the sound it makes. this is a completely different sound and occurred about 5 minutes after the truck was turned off.

It's been a month and thought I would ask one more time. I just heard the same sound again. Does anyone have a suggestion?

the certified internet mechanics have failed its probably best to take it to the dealership or trade it in for a new one

Do you have an vehicle alarm system that could be malfunctioning? Were you in same spot when it activated?
Purchase a trail cam -like hunters use- and set it to watch your truck 24/7 and see if there is a pattern.

No alarm. It does it like 5 to 10 minutes after cutting the vehicle off. And it doesn't do it every time. It lasts for a few seconds and that's it.

This will be of absolutely no help whatever, but I had a 1st Gen Taco that would intermittently, randomly make a sound like a heavy coil spring unwinding. Sometimes when running, sometimes when off. Did it the whole time I owned it. Never did figure it out. One of the mysteries of life.

I'm guessing the air injection pump and am hoping it's normal. Was hoping it was something others had noticed!

I like my four runner like most of you guys and gals, but I gotta say. I don't sit in it for 15-20 minutes coddling the steering wheel to see if she moans and groans.

My wife has a 2019 RDX with what sounds like the same issue. The cause was a faulty AC expansion valve. I don’t know anything about AC systems, but it could be something to look into.

Apparently you didn't read my original post. Nobody is coddling anything. I simply got out of my vehicle and was still in the garage when I heard a strange noise coming from my vehicle. But thanks for your helpful post.

Now and again my evap system near the fuel tank will make noise only 5-10 minutes after shutting down. The noise only last a few seconds.

Yes, I have read the manual regarding the 5 hour evap purge and have even heard it at around 5 hrs.

However, this noise comes from the same area and is definitely not 5 hrs after shutting down. It takes me 5-10 minutes to change my clothes and shoes and get everything ready to go mountain biking.

Maybe that's what it is. I've also heard the ABS pump can also make noises after cutting the car off and that it's normal.

I appreciate the responses!