CR Intake Manifold: The Hole Explained

Hi.

While I was just examining the intake manifolds and trying to locate a rattling noise on my colleague's CBAB engine, I found this:

(at least) The CBAB has a hole in the intake manifold!

Does anyone know what this is supposed to be used for?

At BLS, there's a specially insulated "caudal tube," and someone designed a hole in it and added a huge arrow!

Hi,
Is the hose connected to the air filter housing on the air intake side?
Herbert.

The arrow shows the air the way, otherwise it wouldn't know where to go, especially warm air from the engine compartment is not good...

Herbert wrote:

Hi, Is the hose connected to the air filter housing on the air intake side? Herbert

What exactly does "luftseitig" mean?
On both sides of my air filter, there is air .

Yes, that's the connection from the air intake manifold to the air filter, so it's still the "dirty" side.

matthiasTDI96 wrote:

The arrow shows the air the way, otherwise it wouldn't know where to go, especially since warm air from the engine compartment is not good...

That's exactly what I thought when, just a moment before, I had given my colleague my earplug.
"viewtopic.php?p=216717#216717"
showed.

But seriously: What's that hole for?

m;

But seriously: What is that hole for?


Possibly a combination for an overall acoustic behavior.
There are thousands of ways to design things and structures that filter certain frequencies, so I think it's likely that it's not entirely unreasonable.

http://www.wocogroup.com/Akustik.57.0.html

Hi,
"With 'luftseitig', I meant 'not motor-side'." I just couldn't think of a better expression.
It probably has something to do with intake noises, and that's what people are also talking about online.
*** The arrow might be used to correctly align the airflow. Otherwise, the air wouldn't know. ***. Otherwise, one must attribute it to the immeasurable advice of Mr. Volkswagen.
Sure, here's the translation:

"Best regards," or "Sincerely,".
Herbert.

Hi!

My first thought when I read that was...
It was also in the direction of sound design.

Sometimes you just need to close it up and take a ride, paying close attention. But maybe it's just a replacement part, and for certain engine codes, the hole needs to be there, while for others, it doesn't. To help the mechanic know where the hole should be, there's an arrow.

Quote:

for certain ICD codes

According to my information, all CBAB and CBBB are located in the 3C area.

However, other models with these mass-produced engines likely have different pipes because the geometry is different.
I'm going to take a look at the current models in the showroom.

m;

HM.

Warm air intake is number 8 in here:
http://www.jimellisvwparts.com/images/parts/VW/fullsize/634129600.jpg

But shouldn't it connect directly to the air filter housing?
Because the version for "cold regions" is slightly different.

The lower inlet here is for warm air.
https://system.recopart.se/Bilder/delart/F/564131_1_F.jpg


I will try to cover it up (or have it covered up) .

m;

Okay, so...
Okay, so thanks to the exploded diagram and your photos, it's clear now!

The hole serves either a) as a heat shield (since the intake pipe runs so close to the EGR valve, as it appears in your photo...) and/or b) cools the component behind it (the EGR pipe?).

The small amount of air lost in the intake airflow is negligible in a diesel engine because there is always an excess of air, and the air filter housing still receives enough "pressurized air" even with that hole.

Does that make sense?

haithamina

haithamina wrote:

Rust protection. ... Does that make sense?

Well, the EGR valve is cooled by the coolant (and even controlled by it).
A little bit of flatulence won't change anything about the buildup of intake air.

And the 16V BMR also has a bump for the EGR system... but no arrow-shaped hole!

m;

"Am I missing something? Shouldn't there always be a vacuum, even a minimal one, in that area when the engine is running? How exactly is air escaping from there? It certainly won't create any cooling effect."

Then it's even more likely that it serves as an emergency intake if, for example, a truck's tarp has been sucked in while driving on the highway .

I believe there's a much simpler explanation:

This is the cheapest version of the anti-caulking tube!

Instead of installing an expensive, "padded" pipe, as is the case with EOS in series and with others upon customer request (as I reported ), a calculation of resonance is performed here, and a simple hole is installed.

To the best of my knowledge, "kaudern" refers to the backflow of the air column, i.e., against the normal flow direction. This creates noise because the intake manifold in the scavenging system acts like a trumpet.
If the air column is allowed to dissipate, for example, through a hole, it will not produce a trumpet-like sound.

m;

CFGB comes from the factory without a hole and is only compatible with arrow-shaped fasteners.

Should I call a doctor for you?

I'm almost willing to bet that there's a component from one of the group's vehicles stuck in that hole. Besides cost-cutting measures, I can't think of any other reason for it.

The rattling in the engine compartment caused by loose, poorly manufactured plastic parts bothers me personally much more. Or does anyone have an explanation for that...? Is that perhaps considered "sound design" in your opinion?

You're just overthinking it, sorry.