Complete Independent Throttle Body (ITB) disassembly

[Casa de Mesa]

Looking for a DIY on the full disassembly of the ITBs. I want to completely strip them down so I can get the exterior Cerakote covered.

Examples here, I'd match the original BMW natural aluminum color as much as possible:

https://www.cerakote.com/project-gallery?htids=Engine

I can find plenty of DIY's on removing them as a unit (all 6 at once, which is exactly what I've done) but I now want to complete the disassembly. It's easy enough to just tear into it as it's not very complex. However, I'm worried about disrupting the factory throttle stops. I'm also worried about getting them back in sequence. That is, I'm sure adjusting them so they all open at exactly the same amount and rate isn't straightforward. I have the eManualOnline/ BMW TIS instructions, but I'm wondering if anyone has done this.

Is this a terrible idea?

Gracias,
-Casa

Edit: added a photo, not that this does much good, but everyone likes a photo!

[bigjae46]

It's been awhile but don't remember it being very tricky. Disconnect the actuator arms. Then you slide the throttle bodies and ball joints off the rail. The tricky part will be removing the butterflies. You will likely screw up a couple of the screws that hold the butterflies in. Have a plan to replace them. I think I got replacements at McMaster-Carr. It's been a couple of years so don't have the part number. I'm pretty sure the screws are brass.

[Slideways]

If you have not done this before, best to leave it as is and skip the coating for now. The last thing you want to do during a rebuild is introduce another variable. If it ain't broke...

[maupineda]

Or do ice blasting, since you took them out it maybe inexpensive

[Mayan-Viking]

If you want to properly ball you are going to have to chrome them...

[Chanman1029]

I wanted to do this too, but I was too worried about taking it apart and messing something up. I just took mine and sand blasted it to get all the corrosion and gunk off. It looks pretty good still!

[Casa de Mesa]

It's been awhile but don't remember it being very tricky. Disconnect the actuator arms. Then you slide the throttle bodies and ball joints off the rail. The tricky part will be removing the butterflies. You will likely screw up a couple of the screws that hold the butterflies in. Have a plan to replace them. I think I got replacements at McMaster-Carr. It's been a couple of years so don't have the part number. I'm pretty sure the screws are brass.

I've disassembled throttle plates before on a V8. I know the pain with those brass screws. Will check out McMaster-Carr or the like.

If you have not done this before, best to leave it as is and skip the coating for now. The last thing you want to do during a rebuild is introduce another variable. If it ain't broke...

It ain't broke, but I'm so far past the "if it ain't broke" stage that I figure why not make life more difficult on myself.

Or do ice blasting, since you took them out it maybe inexpensive

Great idea here. I might see if I can find a local vendor. There's just a little bit of oxidation on the ITBs, dry ice cleaning might do the trick. Will look into this.

If you want to properly ball you are going to have to chrome them...

HA! Chrome. That goes against my ethos.

I wanted to do this too, but I was too worried about taking it apart and messing something up. I just took mine and sand blasted it to get all the corrosion and gunk off. It looks pretty good still!

You sand blasted them while they were still assembled?? Weren't you worried about dust and grit getting in the bearings or other parts?

[Chanman1029]

You sand blasted them while they were still assembled?? Weren't you worried about dust and grit getting in the bearings or other parts?

Not at all.
I guess technically it was glass media, rinsed it with water, high pressure air dried it. Then thoroughly cleaned everything with carb cleaner. Works just fine, and looks great too

[Santino]

I have disasembled them, without taking out the butterlies and taking out the screw stops, ans send them to vibration polish, should have them tommorow and start to reasamble them
will come back with picks if its enough ore they need further disasembly to take them to 100%

[thegenius46m]

You guys need to balance them after using the TIS adjustment procedure and make sure they are in spec otherwise they will leak or not open all the way.