Weird Noise After Shutting Off Engine

S

Stockton

New member
Right after I park my 4Runner, the engine makes a somewhat weird noise, almost like a jet engine letting out it's last breath or, another way to describe it, it sounds like a robotic/mechanical decompression noise. It doesn't sound bad but was curious to see if anyone else has experienced this and if anyone knows what this noise is and where it is coming from.

I never experienced this on my prior Toyotas.

Thanks!


2014, LE, 4X4, Nav, Silver
 
Register to hide this ad
It's the new emissions stuff in the '13 & '14's. It's coming from that thing in front of the air intake where a secondary battery would go.
 
Gabex35 said:
It's the new emissions stuff in the '13 & '14's. It's coming from that thing in front of the air intake where a secondary battery would go.
Click to expand...

OK, I remember reading about the 2nd battery space that disappeared .... interesting that these new emissions parts are making a peculiar noise. So, (off topic), what is a typical reason someone might want to use a 2nd battery on a 4Runner or any vechicle?

Thanks Gabex35!
 
Stockton said:
OK, I remember reading about the 2nd battery space that disappeared .... interesting that these new emissions parts are making a peculiar noise. So, (off topic), what is a typical reason someone might want to use a 2nd battery on a 4Runner or any vechicle?

Thanks Gabex35!
Click to expand...

The answer is in this thread http://www.toyota-4runner.org/5th-gen-t4rs/63923-noise-comming-rear-my-4runner-limited.html and all the 5th gens make that noise.

2nd battery can be handy for expedition rigs that run a lot of accessories that constantly draw current even when the truck isn't running, like a fridge. That way the battery that starts your truck should never (in theory) be too drained to turn it over.
 
Intruder said:
The answer is in this thread http://www.toyota-4runner.org/5th-gen-t4rs/63923-noise-comming-rear-my-4runner-limited.html and all the 5th gens make that noise.

2nd battery can be handy for expedition rigs that run a lot of accessories that constantly draw current even when the truck isn't running, like a fridge. That way the battery that starts your truck should never (in theory) be too drained to turn it over.
Click to expand...

Appreciate the info Intruder - thanks for being nice to a noob!
 
This is a feature you can thank the feds and the left wingers in California for. The noise is caused by the air induction pump or AIP. The AIP reduces start up emissions for the EPA and doesn't impact engine performance but can make you fail emissions because the check engine light will appear if it is not functional. Tundra owners have reported early repairs costing thousands of dollars out of warranty due to early failure. So yeah that is the noise.
 
Wonderful secondary air injection pump, surprising that the 4runner just was inflicted with this POS a couple years ago. Some of my other vehicles have had them back to the 90s. Just be glad yours doesn't have rivets that have loosened from vibration and sounds like a rape whistle for 90 seconds every time you start the vehicle.
 
gm4life said:
This is a feature you can thank the feds and the left wingers in California for. The noise is caused by the air induction pump or AIP. The AIP reduces start up emissions for the EPA and doesn't impact engine performance but can make you fail emissions because the check engine light will appear if it is not functional. Tundra owners have reported early repairs costing thousands of dollars out of warranty due to early failure. So yeah that is the noise.
Click to expand...

I wonder if we are talking about the same noise. Because I only hear this odd noise right after I shut off the engine and it only lasts about 3-4 seconds. The other thread mentioned above seemed to talk about a noise from the rear of the vehicle. This noise is definitely coming from the engine bay. I'm going to record the noise and post it up on youtube and share the link...
 
Stockton said:
I wonder if we are talking about the same noise. Because I only hear this odd noise right after I shut off the engine and it only lasts about 3-4 seconds. The other thread mentioned above seemed to talk about a noise from the rear of the vehicle. This noise is definitely coming from the engine bay. I'm going to record the noise and post it up on youtube and share the link...
Click to expand...

Similar noises, two different culprits. In the 5th gens prior to the AIP ours will make a noise from the rear of the vehicle (gas tank letting out pressure, yours will do the same)...in vehicles with the AIP you will get a noise from that system in the engine bay as well.

Everything is working as it should.
 
Will the AIP in 4Runners self destruct like it did in the Tundra, and then Toyota will refuse to honor the warranty?

Is this like a smog pump older trucks had, except that it only runs for a short time at start up and shuttown?

I remember having to gut the smog pump or finding an idler pulley to take its place on my FJ60.
 
Stockton said:
Yes, that sounds about right. Here is the youtube link of the noise for good reference:

4runner Weird Engine Noise - YouTube
Click to expand...

I didn't hear anything in that video. The AIP noise is an electronic spinning type noise for about 1 sec just as you turn off the engine. At 13,000 miles, mine is starting to make a loud clicking noise at the end of the spinning noise, so I wounder if it is starting to go out.

Luckily All of the parts are pretty accessible, so when it does fail it won't be too hard to replace. The V8s that have the AIP, have it mounted under the intake manifold, which has to be completely removed to replace the failed AIP
 
Mine makes the same noise you hear in the video. It is faint, and at the very end for 2 sec but it sounds all too familiar. Thanks for posting that video.
 
My '14 LE makes the same noise. Thanks for posting the video, OP. I was going to take it back to the dealer and ask what the hell the noise was.
 
Just picked up a 2015 Limited and heard this. Seems like I am having the same noise, just doesn't sound like something you would expect to hear every time you turn the car off. I took a video in my garage that you can pretty clearly hear it.

http://youtu.be/FyZZMvAry4A
 
You must log in or register to reply here.

Members online

Total: 419 (members: 3, guests: 416)

Forum statistics

Threads
278,310
Messages
3,554,079
Members
248,016
Latest member
Advally Service

Share this page

Trending content

Back
Top