2004 3.2 MAP Filter Port Restriction

[Bazooka]

Hi All,

I recently removed the MAP filter from the lower intake manifold to inspect/clean. I also gently poked a cotton tip into the filter port to make sure it was clear.

I then gently poked a long-handled phillips-head screwdriver into the port in the intake manifold (just out of curiosity) and was met with what felt like a spongy restriction just inside the manifold. If I angled the screwdriver tip toward the front of the engine it would slide past the restriction and slide all the way into the manifold. This action was repeatable.

The intake system and EGR should be pretty clean since it was sonically cleaned in May 2018 (see collage pic) when the new head etc was fitted.

Can anyone shed any light on what the restriction might be?

Thanks - Bazooka

[Bazooka]

It would appear that poking things into the intake manifold on 3.2 Paj's is not such a popular pastime

Anyway, I'll be replacing my MAP Sensor Filter (more accurately known as a Boost Sensor Filter) next week and intend to identify what this restriction might be.

Update to follow...

[Bazooka]

Bump

Update:

I replaced the Boost Sensor Filter (Aka MAP Sensor Filter) today but could not see the restriction inside the manifold with a mirror and torch. The filter thread in the manifold aperture is only ~8mm diameter and the restriction is felt about 45mm into the aperture.

It doesn't make sense (to me at least) that there should be anything anywhere near the outlet in the manifold that leads to this filter.

Anybody please care to check their intake manifold as a comparison? The filter is removable with a 24mm deep socket (loose fit) but I suspect it is actually 23mm.

Any help greatly appreciated - cheers Bazooka

[Axis]

Are there butterflies in the NP inlet manifold? My NS has them as per pic. Could you be hitting them - is there a metallic sound?



Otherwise not sure. Have not heard of a MAP filter before - is it on the Manifold? Pretty sure my NS doesn't have one but happy to be educated!

[Bazooka]

Are there butterflies in the NP inlet manifold? My NS has them as per pic. Could you be hitting them - is there a metallic sound?



Otherwise not sure. Have not heard of a MAP filter before - is it on the Manifold? Pretty sure my NS doesn't have one but happy to be educated!

Hi Axis,

Thanks for your input. The feeling I get when I poke the screwdriver into the manifold is like poking into a firm foam, like high density foam, so it certainly isn't metallic.

I think what you have in your manifold are called swirl flaps or butterflies. I'm guessing they are designed to better circulate air in there. If you look at the photo collage in my first post you'll see our manifolds are quite different and I certainly don't see anything in the open areas of my cleaned lower manifold.

You should have a Boost Sensor Filter on your NS. (I incorrectly referred to it as a MAP Sensor Filter because it's a filter at the start of the air pressure tube from the intake manifold to the MAP Sensor on the firewall). The intake manifold for the NS DiD had to be re-engineered (and replaced under warranty as necessary) to move the outlet for the Boost Sensor Filter higher up on the manifold because they were regularly clogging up. It'll be there somewhere - just backtrack from your MAP Sensor.

I'm waiting on someone else who might have poked at least a 6mm object into the Boost Sensor aperture in their manifold before I consider pulling mine off to see what's going on...

[BruceandBobbi]

Can't find a filter on our NS. It still has the original manifold also.

[Seigried]

I have the revised manifold on my NS. It a small pipe tapped into the inlet manifold. There is no filter.

Sent from my SM-G900I using Tapatalk

[Bazooka]

Ah, ok MM decided to do away with the filter and obviously greatly change the design of the manifold. Not sure it was for the better though.

Cheers..

[Axis]

Hi Axis,

Thanks for your input. The feeling I get when I poke the screwdriver into the manifold is like poking into a firm foam, like high density foam, so it certainly isn't metallic.

I think what you have in your manifold are called swirl flaps or butterflies. I'm guessing they are designed to better circulate air in there. If you look at the photo collage in my first post you'll see our manifolds are quite different and I certainly don't see anything in the open areas of my cleaned lower manifold.

You should have a Boost Sensor Filter on your NS. (I incorrectly referred to it as a MAP Sensor Filter because it's a filter at the start of the air pressure tube from the intake manifold to the MAP Sensor on the firewall). The intake manifold for the NS DiD had to be re-engineered (and replaced under warranty as necessary) to move the outlet for the Boost Sensor Filter higher up on the manifold because they were regularly clogging up. It'll be there somewhere - just backtrack from your MAP Sensor.

I'm waiting on someone else who might have poked at least a 6mm object into the Boost Sensor aperture in their manifold before I consider pulling mine off to see what's going on...

No worries. I have the original NS manifold. No issue if it is clean and an EGR block in place. Mine is like the BruceandBobbi's - just a pipe on the inlet manifold to the MAP sensor.


Can't think what else you may be feeling when you poke in the screwdriver....

[Bazooka]

No worries. I have the original NS manifold. No issue if it is clean and an EGR block in place. Mine is like the BruceandBobbi's - just a pipe on the inlet manifold to the MAP sensor.

Makes me wonder what the filter does on mine then - maybe just something else to block up

Can't think what else you may be feeling when you poke in the screwdriver....

It does seem weird. I'm going to use an endoscope tomorrow arvo to try to identify the restriction. If that fails I'll look at removing the manifold.

[Bazooka]

Update

Well the endoscope vision was too blurry to identify anything in the Boost Sensor Filter aperture in the intake manifold. But strangely enough the restriction is no longer detectable. I can only think that it may have been a lump of crud inside the intake adjacent to the sensor aperture that has since dislodged.

Anyway at this stage I'll just monitor the Paj's driveability and see how things go.

Cheers - Bazooka

[Axis]

Makes you wonder how much has already built up since the clean. I take it you have no EGR block in place?

[Bazooka]

I didn't have the EGR blocked until just recently and yeah I doubt anything much would have built up in the 20,000k's since the clean was done. The couldn't block the EGR while the new head was under warranty anyway.

I also recently fitted a rudimentary catch can so at least I'm now eliminating any crud buildup in the intake...