2013 4.0L mooing on shutdown

I'm still pretty new to these gen2 vehicles and their newfangled equipment.

My 4.0 moo's when I switch it off. My friends FJ with a 4.0 does the same, but louder.

He says this is normal for these engines, but I want to know... what the heck is it?
Why does it do this? I have to assume there's some sort of equipment in there designed to do a function, but it sounds like that.

Where's the cow?

 

The sound you are hearing is the shutdown purge of the SAIS system. Essentially blowing out any moisture through the air valves. Its normal.

Look into the Uni Filter mod for the sais system so your foam filter doesnt degrade and mess everything up.

 

I agree. And be glad you are hearing it.
The year model before yours didn’t do this, which leads to a SAIS failure. Expensive.
I’d start worrying if you DON’T hear it.

 

Ah ha, a keyword to search!
Thanks for the quick info!

"The secondary air injection system is for emissions control as it sucks more air in. It only runs at startup and shutdown"

Emissions- figures...

"Toyota decided to use crappy foam filters for the secondary air injection systems, for 2012 to 2015 Tacomas. The side effect of this is how the foam filter degrades. The foam filter can disintegrate and be sucked into your intake, causing potential damage."

Oh lovely- more work to un-do the "upgrades" caused by emissions.
Guess I've got another project to add to the list of things to fix caused by adding too many plastic parts and garbage standards to trucks.

Got to love all the upgrades on these newer trucks...

 

Nearly All false. Its the REAR cats are what is stolen out of our trucks (and 3rd gens), front cats are not easy to cut out on either models.

Toyota Only put the SAIS on the v6 in 2012 due to epa changes, the single vvti 1GR v6 found in 4 runners since 2003 (and tacomas since 05) has literally the same exhaust manifold / primary cat dimensions as the 2012+ with the sais - yet never had an issue with temps.

The SAIS only runs for a function of emissions on startup when the engine is BELOW operating temp - read COLD MOTOR and exhaust. The SAIS has NOTHING to do with temperature control of the primary cats. The shutdown purge is just that, a purge of air to get rid of moisture build up in the air valves.

 

It's like a cows opinion. It's moo.

 

relax.


You're right, I'm thinking tundra 5.7s for primary cats. I'm mixed up there.

I'm loose with info, I'll fix it.

Sorry to get you so bent out of shape over this.

 

Hmmm...I'm a bit jealous that my 3rd Gen doesn't Moo.

 

You’ve got to milk them every so often or the teets get swollen.

 

Glad I have a pre-cattle model Tacoma.

 

Emissio-cow

 

My 99 doesn't moo

Sadly, I'll be selling her soon... the 2013 has survived a few months of abuse so I think I'm ready to trust it. The mooing just makes me uneasy.

 

So, the '99 is going out to pasture. ;-)

 

Curious- why are you selling the ‘99?

 

With any luck, it's going to give someone else another ten years of excellent service.

I'm up in Maine- it's incredibly hard to find rust-free vehicles around here. I brought that one up from florida and have been spraying the underside, frame inside and out, every fall with fluidfilm (lanolin) - it's the least rusty truck I've ever touched. 225k miles and in tenish years all I've had to replace is the alt, front ball joints, and a bunch of plastic bits that were cooked from its life in florida.
maybe I'll make a post in the Gen1 forum about her today.

 

STOP- you need at least 50 posts to sell here! You’ll get the Ban Hammer, maybe a warning and post removal.

I’m up in Coös County NH- just as hard on vehicles.

 

2 min fix.
https://m.youtube.com/watch?v=uG87HzkNzCI

 

Err- thanks for the heads up!
I didn't realize there was a post requirement... or that I didn't have 50 posts.
I made this account years ago for that truck, but it was so problem-free I guess I never really had to post much

 

You’re welcome! Hang around for a few days and you’ll get there.

 

thanks!

I'll order in the part today.