Well here's something new - to me...

Cabin vent filters? Knew about the filter behind the glove-box but had no clue about the vents behind the rear wheels. Yup, that's a no-pooper, they are there and all you have to do is remove the rear bumper to service them..

Here it is: https://www.srqfabrications.com/store/10-5th-Gen-4Runner-Four-Cam-Cabin-Vent-System-p419133896



Found this on another forum. Maybe it's common knowledge but was new to me..

 

Yep, discovered mine when I pulled the rear bumper last weekend to replace my damaged bumper trim. Never knew they existed before that.

 

Welp mine will never get changed.

 

The first time I saw it was on that same page.

 

These are common and “hidden” on all vehicles. They are baffled one way pressure vents that allow the the increase in air pressure to escape when you shut the vehicle doors.
Otherwise you'd have to slam the hell out of the doors to shut them. Additionally as HVAC continues to pump in air they regulate the cabin pressure for that too….

they are for air escape only. Not “filters”. Air flow out only. Rubber baffles close off air flow the other direction.

Know this how???… I worked in vehicle body engineering development for years…

 

I have to slam the hell out of my doors on my '22 4Runner, but not at all on my '19 (I bought it new). Has there been a change?

 

Is be surprised if they changed. They are engineered based in cabin size and air pressure spikes from doors shutting and hvac. None of that has changed in any appreciable way.
Id suggest your door latch striker needs adjusted. In rare instances the baffle could stick but highly unlikely.

 

It's on all of the doors on my '22. It's like it's air tight.

 

Well, this explains why I hear so much road noise coming from the rear.

 

Same here. I find myself closing the door three times to get it shut tight because I'm used to closing my other car doors softly.

 

Yeah. This is why they are always at the rear down low to try and mitigate/hide as much noise As possible.

@thatbadassguy-
That sucks. Getting to them to check function is a bitch.
Another way to test- If you leave one door open and shut another is it still a bitch? If it is it aint the vent and something else. Like striker placement, door adjustment, seal compression

 

Also, as the vehicle ages the door seals will take a bit of a set. Toyota may be compensating for that but thats a complete guess.
The test above will tell you if its the vent which as i said- unlikely…

 

obviously doesn't need servicing. if so, my dealer would be charging $100/side every 10k miles

 

I was suspecting something along these lines. So basically, the product linked is a solution in search of a problem?

But this brings up a question. Have you all noticed that the rear window sucks major wind when it’s open? Im imagining that when the rear window is open, those vents get pushed open. I wonder if allowing these to remain shut would help cabin air to get drawn out the open rear window, instead of pulled in. The amateur aerodynamicist in me says the only real solution is tons of vortex generators along the rear of the roofline and the side of the vehicle at the back, but that would look stupid.

 

I’ve seen those types of vents on other cars. Similar concept to outflow valves on pressurized aircraft except not actually controlled by a pressurization controller.

 

Interesting point on the rear window. It surely does suck in a crap ton of debris. Even with it closed Ive noticed the back of the Runner gets nasty fast…. Aerodynamics of the vehicle cause this…

As for that product shown- yeah that is inventing a problem to solve. These valves are one way flow which is out not in. Its a rubber membrane typically.
So to put a filter on it doesn’t compute unless Toyota’s pressure vent is doing more than typical… which dunno what that could be as it would make zero sense to be drawing in air, dirty air, from the rear of the vehicle and then to do what with it?

 

If you're talking about driving with the rear window fully open, then yes, you'll get wind, rain, dust, etc. coming into the vehicle. If I want flow-through, I open the rear window maybe 1/2" or so.

 

Yes.

True! Even with it shut, the hatch collects a ton of dust on dry gravel and dirt roads.

 

Not to mention exaust fumes!!

 

Correct me if I'm wrong but this would be more beneficial for one who has aftermarket rear bumpers where the vents are more exposed?

 

As previously stated their purpose is to relieve cabin pressure when the doors are closed with all windows in closed position. This probably helps to keep fixed glass from popping out on hot days when there is a sudden pressure change. OEM looks pretty wimpy but I guess that beats listening to a plastic or metal flap moving about.

 

How would they be more exposed? They would be covered by the steel bumper, instead of the stock plastic bumper cover. They wouldnt suck in any more air, because the whole thing isnt meant to let air in at all.

The more I think about it, the more puzzled I am that someone would make or even offer something like this for sale. The only reason that part would need a filter is if someone was particularly dirty and wanted to protect the environment from things that are escaping the vehicle.

Or the rubber flap is so stiff that it doesn't close any more. At which point, you’d just order a new one.

 

Ive wondered also why. What they came up with does not look cheap.
Idea that struck me— wonder if those who extreme off road and water cross—- is there possibly situations this cabin vent would be under water and make its way into the vent due to water forces and such. The factory ones are not designed for those conditions, im confident.

However, at a depth like that wouldnt water just come in the doors and hatch though i then thought which led me back to so whats the point shits flooded inside anyway…

 

Even though Elon Musk creeps me out for various reasons, it’s fascinating to listen to him in interviews where he talks shop about engineering and production (related to spaceX).

A big principle he sticks to is simplification and reducing part count. If one part can can do the job of two, then get rid of one of them. If it can’t, then ask if one can be redesigned to eliminate the other part.

This might look like it’s flimsy, but it only has to do one thing in life, which is simply get out of the way when air wants to leave the vehicle. If a rubber membrane can puff out of the way, and return under it’s own weight…mission accomplished.

Somebody else might want to design it with a solid plastic flap, with a spring push it closed, and an actuator to and air pressure sensor to trigger it. Or an external cover when it is already covered by the bumper cover, or an air filter for escaping air…. But that just seems a bit overlycomplicated

 

they are air vents , when you close your doors the air preasure needs somewhere to go and that is where. don't clog them up. it will be hard to close doors.

 

My understanding is that is that these things aren't that important for doors closing... since the interior volume isn't being decreased, and any air "pushed" into the cabin by a closing door is more than able to be handled through the open HVAC duct work, etc...

...The reason you need these large vents for pressure relief is for accidents and particularly airbag deployment. In those instances the interior volume of the vehicle is decreased not just by a larger margin, but also incredibly fast. That's when you need these types of vents otherwise you run the risk of over-pressure injuries (to eardrums, etc).

 

Makes sense…

 

Just noticed this yesterday

 

Hmmm, now Im thinking. Perhaps this is another aftermarket opportunity to cater to the well-provisioned overlander? Pressurization kits might come in handy. Im sure we could get a 4runner to hold an 8000ft cabin while scaling the Andes.

 

That’s right - there just ain’t enough 4runners accessories out there…