V6 Ecotec Plenum Intake Polishing Question, Does Plenum condition matter?

[Gabster118]

Hey Guys, So I was looking into properly polishing up my whole Plenum Intake.
I've already got the cover polished up and now I want to do the Plenum itself.
The question I have is does the the condition of the Plenum matter?
I was going to properly sand and polish the inside and outside of the Plenum.
Since I'd spend a lot of time on getting it perfect my car would be undrivable
for a while so I went to the wreckers and picked up a whole Plenum off another car.
Does it matter what condition the plenum is in, would it matter whether I polished up
my original Plenum that's done 100,000kms or the one from the wreckers that's done
200,000kms. Since I would be polishing the inside and outside,
it would be the same piece of metal right? Basically like new?
So all up my question is, Do I temporarily put on the Plenum from the wreckers on
my Commodore and polish up the original one, or do I simply polish up the one from the wreckers
and change them once over I'm done. Since replacing the plenum is a fair bit of work
that requires depressurizing the fuel lines, I think I would get a mechanic to change
them for me. Your help much appreciated, Cheers
Gabriel.

[westerlybreeze]

Hi Gabster,

Firstly I hope this other plenum is the same as yours?
VS-early VT are grooved to use O-ring type gaskets, where late VT onwards use flat steel and paper gaskets.
It's not a major, but you'd need to get the right gaskets to suit.
Also some plenums don't have the EGV for emissions of the side, which could be a good thing depending on the emission laws where you are.

I wouldn't think a bit of mileage would make a difference, only if it's corroded or damaged. If it were me, I'd polish the one from the wrecker..
The fuel lines don't need to be disconnected, it is possible to remove the plenum without disconnecting them.

Good time to fit some Mace insulating spacers!!

[GRPABT1]

LOL at de-pressurizing the fuel lines. If you are really that worried about a little squirt of petrol then just pull the fuse for the fuel pump and crank the car over a few times on the starter.

[Gabster118]

The plenum I got from the wreckers has O-ring type rubber gaskets.
only thing is that its off a VT and mines a VX, apparently the lower inlet manifold casting is different??
I might have a crack at changing them to see if they fit since the fuel lines don't need to be disconnected.

and yeah I'm definitely gonna get the Mace spacers

[westerlybreeze]

The plenum I got from the wreckers has O-ring type rubber gaskets.
only thing is that its off a VT and mines a VX, apparently the lower inlet manifold casting is different??
I might have a crack at changing them to see if they fit since the fuel lines don't need to be disconnected.

and yeah I'm definitely gonna get the Mace spacers

Ah yes the crackcase breather hole from the PCV could be in a different place, later models place it towards the centre where early VS-VT is rearward in the plenum.
Just remove your plenums lid to see and if different, don't use it. See if the wrecker will swap it.