'09 335i bought at 55K w/ just over 58K miles now. Car has been well maintained according to records but no mention of intake port de-carboning. This is a DI engine. Blogs recommend service as low as 35K but should by 50K for what that's worth. I've noticed no deterioration in performance in my limited ownership and no codes. Is this something to be done sooner rather than later?
Word is BMW wants $600 plus for this service. My local mechanic should be cheaper and is well versed w/ BMW's. Another option is DIY.
BavAuto has a DIY kit w/ pressure pot w/ all hoses, wand, port adapter specific to the N54, walnut shell media and replacement gaskets, currently on sale for $234. Comprehensive how-to video here: http://blog.bavauto.com/15543/
Appears easy enough in the video, Saturday afternoon stuff. I have the air compressor and shop vac. Anybody do this service on the N54, anything to beware of? Do it now or let it go some? I may trade the car this summer if I find the right replacement, Regal GS maybe.
Any advice?
TIA
well that's some kind of awesome 
I would so burn down my garage doing that...
Watched both videos. Fire wins.
Ian F
MegaDork
4/14/16 9:51 p.m.
In reply to slefain:
Yes... but the N54 cleaning is for the head ports, not the manifold so much.
I haven't done it myself, but I've watched it done. A BMW/MINI shop in Philly I've known for years does it for a fair bit less than the dealer. Holy crap a lot of stuff has to come off. While I like to DIY most jobs, I'd probably pay them to do it as I'm sure they'd get it done in a fraction of the time it'd take me.
berkley having to do this e36m3.
Spoke w/ the local mechanic this morning, he doesn't see many problems w/ DI BMW's as VW, Audi, other Europeans as well as late model domestics throwing codes. He recommended letting it go now but quoted $620 in case.
Back to DIY I guess. $240 for the kit ain't bad as I could still use the pressure pot as I don't have one, even though it is pretty small oversize shipping applies. Might be able to just buy the BMW port adapter for $90 and rig my sandblasting stuff or piece together a HF pot setup ftw.
By the sound of it DI is gonna be a PITA as many vehicles need service as low as 25-35K miles... sounds a lot like they didn't see it comin'. My first thought was a quality aftermarket oil separator w/ catch can, might do that after port cleaning.
Ian F
MegaDork
4/15/16 10:22 a.m.
I've heard the oil separator/catch can doesn't help as much as one would hope. Delays cleaning a bit, but not much.
I've done it on quite a few VWs, AUDIs, and MINIs for rough running and misfires. Haven't needed to do it on a BMW...yet.
If you always use Top Tier fuel, especially Chevron with Techron, and do some sort of induction service (Seafoam) regularly you may never need to to the walnut cleaning.
fasted58 wrote:
By the sound of it DI is gonna be a PITA as many vehicles need service as low as 25-35K miles... sounds a lot like they didn't see it comin'. My first thought was a quality aftermarket oil separator w/ catch can, might do that after port cleaning.
They must have seen it coming, no manufacture alive does a sub 30K mile long term tests of their drive-trains.
In reply to The Hoff:
Gasoline choice doesn't apply with direct injection, since it no longer is injected upstream of the intake valves.
The crud all over the intake valves in the head comes from the crank case ventilation system.
I thought I read some stuff about considering putting an injector or two back into the intake, kind of like the old fashion cold start injectors, and running it to wash down the valves when emissions would not be adversely impacted.
Maybe the guy on here (Alfa?) who does emissions work for a living something about that?
And, of course, the fire method isn't going to work out so great for folks with plastic intake manifolds!
I'd imagine running seafoam periodically would help with deposits on the back of valves and in runners.
Karacticus wrote:
I thought I read some stuff about considering putting an injector or two back into the intake, kind of like the old fashion cold start injectors, and running it to wash down the valves when emissions would not be adversely impacted.
Isn't that how the injection on the FRS/BRZ works?
https://www.youtube.com/embed/zc8aUxBZlsU
Karacticus wrote:
In reply to The Hoff:
Gasoline choice doesn't apply with direct injection, since it no longer is injected upstream of the intake valves.
Bingo.
Personally, I'd run it till I had to do another major service (Timing belt,water pump...something along those lines) OR if it throws codes and starts running poorly.
