The flaps, because of the design, tend to open and remain open in the air current.
So just disable the vacuum to their actuator and they will remain open.

sure? I read on the tech manual and it seems that swirl flap are normally closed..

See below...
The phrase "the vacuum required for port de-activation" means that vacuum is needed for closing of the flaps.
And the flaps are only closed at idle.
So, no vacuum, no flaps closed and they will stay open, as I've said, by design.

Maybe I'm wrong but I read the opposite....

Port de-activation (opening of the filling ports) requires the vacuum...so no vacuum no opening

"Port de-activation (opening of the filling ports) only occurs when the coolant temperature is greater than 10°C, and under the following conditions...[blabla]....The vacuum required for port de-activation is supplied from the engine mounted vacuum pump."

Each intake path is considered a port. Port deactivation means the closing of that port.
There is a typo there, on my document posted above. It should be "closing of the filling ports"...
By closing the port, the air flow through the other one is more turbulent, the exact desired effect, for a better combustion, at idle (below 1000 rpm).

But you don't have to believe me. Go out there and experiment...

Hi Alex

checked again the tech manual and [copy+paste] "....The
filling port is normally closed, and is only opened during certain engine operating conditions by the ECM."

So disabling the vaccum the flaps don't move and the filling port ( the upper one) remains close

I think the only way to operate on swirl flaps is to take the manifold out, and the only way to save them from deterioration is to blank the EGR

Yes, that normally closed is done by using the vacuum. And they will open by cutting the vacuum.
According to your theory, if there is a problem on the vacuum system, the ports will be forever closed and, at higher RPM, will hinder the engine functioning by limiting the air supply.
In reality, any system will be designed in that way that, if possible, when defective, to not hinder at all the engine functioning.

Hello,


Luckily I havent had that flap issue yet, but I was warned to replce the entire manifold during the next maintenance, to avoid catastrophy. I am considering either to remove the old flaps or put on a later manifold already without the flaps, I doubt that these flaps would make any difference....Does anybody have any experince doing similarly and using the car after?

Mine is 2007 built with 160,000 km.

Thanks

I removed them on mine when I did the glow plugs as one of them had already broken off and was wedged in the manifold. If I remember correctly I took the clip off the end and pulled the rod out then blanked the vacuum off (which was also not working because of a split pipe) Mines an 07 and so far I've had no issues with it.

thanks Paul,

so no difference in operation or any error messages from the vacuum actuator after?
what was your milage when doing it?

I am still hesitating whether to replace the maifold with a new one or to remove the flaps simply, but removing the flaps seems to be a safer - and probably also more practical - solution. Anyhow, these flaps dont do much....

No difference at all and no error messages the mileage was high 80s. Probably better off removing them first and saving the cost of a new manifold.

yep, actually the engine should be even better performing, since we are removing an airflow barrier...
on the other hand there must be a reason why the engineers have put the flaps there?!

Those flaps were supposed to be closed only on low engine speeds, up to 1500 rpm, in order to speed up the intake air flow to increase turbulence for better combustion and low end torque.

Hi Alex, do you have yours still in?

Yes, I have the original setup...
Although, I believe they are breaking because they become brittle due to heat induced by the EGR gases.
I've blanked the EGR quite some time ago so I keep my fingers crossed...