“While You’re There” Intake Plenum Checklist

[eacmen]

Taking the intake plenum out for smg relocation and going to gather a list of things to do while its out. So far I have:

- clean ICV
- clean TBs
- coolant sensor near thermostat (is this accessible?)
- rear TPS
- installing oil pressure gauge (i want this for data logging dash)

Any other wear/tear items I should consider?

tia

[Mr.wReckless]

Coolant sensor is accessible, you could consider replacing the starter if it's old and not been done, the 2 coolant hoses that run over it gets really in the way, but if you're also swapping the coolant temp sensor then I'm guessing you're also draining at least some coolant, so you could remove those two hoses to ease removal of the starter.

Also, you could replace the sensor on the TP actuator motor too whilst you're there. All this adds to the cost though.

Regards

Edit to see you already mentioned the TP sensor

[heinzboehmer]

Intake cam position sensor?

Not sure how much it's worth doing though. Kinda expensive and if you're doing the work yourself, getting to the sensor in the future is just another ~20 min of removing/reinstalling the airbox.

[FBloggs]

The intake cam sensor is a fiddle, especially when attempting to accurately route the replacement sub harness...
...So how about injector 'o' ring refreshment?
You know...while you're in there.

Bloody cars.
I had to replace a worn out clutch pivot pin on my 328iS last week.
while I was in there for a $3.00 part ended up circa $400.

[Casa de Mesa]

Ping sensors?

I replaced all 3 of mine when I did motor-out work. No clue if it's a common or uncommon failure point but became a might as well. I actually replaced all motor related sensors, but the entire motor was out so slightly different.

[ac427]

Maybe some alternator work or at least a front belt bearing/pulley swap

[elbert]

Do any of the coolant "pipes" that run under the plenum (or their o-rings) have any issues? I haven't heard, but wondering. I'm thinking of #7 and 10:

[antknee]

what mileage and is the starter original? maybe consider replacing while the intake mani is out.

[eacmen]

what mileage and is the starter original? maybe consider replacing while the intake mani is out.

90k miles. I’m like the 4th owner so no clue if its still original or not.

[eacmen]

Do any of the coolant "pipes" that run under the plenum (or their o-rings) have any issues? I haven't heard, but wondering. I'm thinking of #7 and 10:

Good call will inspect those for leaks!

[eacmen]

Any tips for cleaning out the plenum without a giant hot tank? Trumpets on 1 and 6 seem really hard to get to with a rag.

[Slideways]

Any tips for cleaning out the plenum without a giant hot tank? Trumpets on 1 and 6 seem really hard to get to with a rag.

I think NZ_M3 said to just spray some simple green, let it soak then rinse out the airbox.

The plenum is so easy to remove that I really wouldn't replace anything under there.

[m3_sancho]

You might consider hoses 5 and 3 on the diagram. These are the hoses from the coolant pipes to the heater core. On mine the O-Ring from hose 5 to the long coolant pipe was leaking at 105k miles.

[Casa de Mesa]

Hey eacmen - I started a similar thread not that long ago. Some good ideas here:

https://nam3forum.com/forums/forum/main-forum/e46-2001-2006/162643-might-as-wells