[capt_slow]

I was interested to see how carbon build up would look like after 46K fully stock miles. So I decided to have a look at the throttle body with an endoscope. It was surprisingly easy to take off the pressure pipe from the throttle body. There is definite carbon build-up especially around the edges of the flap, but probably less than I expected as I can still make out the torx screws holding the flap to the hinge.






I suspect the gang here would be a better judge, how does my build-up look? I was thinking of getting the throttle body and intake manifold cleaned at 60K, but not so sure now. Interestingly, ISTA has a procedure for intake cleaning and its the proper submersion method. I would hope any dealer intake cleanings would use this vs. the spray.

[Enabled]

I'd say this is minor enough where a quick intake cleaning procedure with an intake cleaner like the Liqui Moly is enough.

I haven't heard much of dealers doing any actual intake cleaning on 328d at all, and most now are not serviced at the dealers anymore.

[eugene89us]

@capt_slow I think I posted a while ago on these forums about my intake after 30K miles, it was roughly the same as yours. I will attach a photo to here as well.

I agree with Enabled about Liqui Moly. I have been doing preventative intake cleaning with LM Diesel Intake cleaner every 10,000 miles. It is not a perfect result, but cleans the valve and sooty mess around EGR input. It re-soots within 10,000 miles, but only on surface.

If you cannot find any LM diesel intake cleaners, let me know, I have a few extras. Purchased for the future.

[Nijenego]

I have high mileage (115k) 318d (EU), and i recently cleaned MAP sensor. It was completely caked in and full of soot. I don't know how it even worked before i cleaned it. TBH i don't see any real world difference after cleaning, but placebo effect makes me happy little bit i guess

[capt_slow]

Does anyone know what would be the ballpark cost to properly clean out the intake manifold and throttle body, and do a walnut blast at an indy shop?

The next maintenance interval at 60K is becoming quite an opportunity for preventative/proactive work.

• EGR cooler replacement (free via recall)
• EGR valve replacement (parts cost only, labor done via EGR cooler recall)
• Coolant change (free via EGR cooler recall)
• Front diff fluid change
• Rear diff fluid change
• Tranny fluid change
• Transfer case fluid change
• Engine oil change
• Serpentine belt and tensioner change

Given all the work above, and the fact I got my steering rack and valve cover replaced recently under warranty, 60K may be a good opportunity to slap on the KermaTDI Stage 2 tune. That said, it feels almost pointless to do the intake cleaning without installing a catch can.

[Watsey]

I had the inlet manifold on my 330d removed and cleaned in an ultrasonic bath at the BMW Indy that does the more involved maintenance work on the car. The IM had been cleaned by a different Indy but I realised that it hadn't done a particularly good job.

The IM came out pretty much like new. £200 ballpark (remove; clean; refit) in the UK.

The inlet ports were walnut blasted around 20k miles ago and didn't need doing again.

[F30_320D_UK]

Interesting thread. I'm on 82k miles, '13 plate 320d. Seems like I must get on this too, and inspect the state of the build-up