How to (with pictures)- Throttle Body cleaning for smoother idling

[MadeInJapan]

This is actually from another site, (Thanks to Syrup from S.S.), but I found it so good I decided to copy it here. This should also apply to C30's and possibly P1 platformed C70's. First off, if you have opted to remove the air filter box, replacing it with a different intake, then you are miles ahead of those who have to get at the throttle body via taking the air box loose. Anyway, here it goes:

It’s easy in theory but awkward in practice.
I think the throttle body cleaning instructions in VIDA have been written by a Swedish intern – it’s literally a few diagrams and one or two sentences and not enough to get the job done- just enough to scratch you head...

I ended up cleaning the throttle body. As the intake side is was spotless – but on the engine side it was filthy and covered in gunk.

Here’s a few tips to make life easier.
Tools:
1/4 drive ratchet with various extensions & sockets
Regular Torx bits
Screwdriver
Small spanner to suit Torx bit

Removal guide
1. For improved access:
- Remove the dipstick
- Remove the fixed fresh air inlet snorkel
- 2 x bolts as indicated (10mm?)
- 2 x retaining tabs at the front of the snorkel
- Twist & lift out
- Remove the flexible adapter to the airbox
- Twists off
- Remove the airbox elbow adapter
- Easier to remove the air filter & push out the elbow from the inside of the airbox



2. Loosen the hose clamp (socket or screwdriver)
- The OEM hose clamp won’t go anywhere, it’s clipped to the edge of the throttle body hose

3. Undo the two front Torx screws
- If room is tight, ditch the ratchet and use a small open-ended spanner on the Torx bit as shown



4. Undo the two back Torx screws (done by feel)
- 1/4 drive ratchet + 1.5 inch extension and the Torx bit worked for me
(Push the hose out the way)
(Remove the throttle body and unclip the wiring)
- Depress 2 x tabs on the connector and pull off
- Ensure you don’t lose the green silicon rubber gasket

5. Clean with throttle body cleaner and wipe with a lint free cloth
Also a good time to inspect/clean around the oil filter housing

6. Installation is reverse of removal, but make sure that:
The throttle body wiring is not kinked or twisted on installation
The throttle body seal is snug in the plenum chamber
Don’t over tighten the screws – VIDA says 10 Nm which is just about 7 1/2 Ft Lbs- it's very light (but how would you get a torque wrench in there! If concerned, practice on a bolt somewhere that doesn't matter to get a feel for 10 Nm...then get on it but easy).
All the fresh air snorkel parts are seated correctly

It didn't seem to need a cleaning but after it was done, I noticed a much smoother idle so I'm glad I did it!

[ricsamdan1]

Hi, I noticed an issue with my C30 R-design this morning, it started to rev over 1000rpm and does not come back down, italso makes a sort of whining, whistle noise and I first thought was turbo but it is coming from the box connected to the throttle body (air box I think?). Would you say it is the throttle body or air filter? or something worse??

[MadeInJapan]

Whistling sounds like the pcv system which is basically the entire oil filter housing on our cars. These were under a factory recall and mine was done replaced a couple of months before I bought my car this past year. Mine is an '07 S40. You might call the dealer with your VIN to see if yours is also under a recall, then the work is free!!