Carbon cleaning time?

[doublevanosrc]

Pushing along with 89k on the odo, the car feels great in every regard except i feel it has lost in the power department. I know I'm due for plugs and a new air filter soon however i wonder if that would do the trick or should i look into get the valves blasted clean? Don't get me wrong it still pulls hard especially in 2nd gear but i feel sometimes down low it seems to feel a bit weak.

Am i going crazy?

[1 Bimmer]

How old are the plugs? These motors like good/newer plugs.

[dtla1]

Originally Posted by doublevanosrc

Pushing along with 89k on the odo, the car feels great in every regard except i feel it has lost in the power department. I know I'm due for plugs and a new air filter soon however i wonder if that would do the trick or should i look into get the valves blasted clean? Don't get me wrong it still pulls hard especially in 2nd gear but i feel sometimes down low it seems to feel a bit weak.

Am i going crazy?

I thought the same thing a couple months ago at about 95k miles on my 2011 N55. Took it to a shop, they removed the intake and told me the valves look fine, no need to be cleaned. Apparently the N55 engines don't build up as much as the N54.

[zx10guy]

At about 92k miles, I had the plugs done along with new coils. You might want to consider adding coils to the list.

[doublevanosrc]

Originally Posted by 1 Bimmer

How old are the plugs? These motors like good/newer plugs.

Plugs were changed at 50k miles.

[JM98]

Guy pulled almost 25hp more just from a valve cleaning, have seen upwards of 40hp on other forums:

https://www.e90post.com/forums/showthread.php?t=1099996

The valves can get pretty bad if you've never had em cleaned. Definitely recommend with your mileage.

[zx10guy]

Originally Posted by JM98

Guy pulled almost 25hp more just from a valve cleaning, have seen upwards of 40hp on other forums:

https://www.e90post.com/forums/showthread.php?t=1099996

The valves can get pretty bad if you've never had em cleaned. Definitely recommend with your mileage.

That thread is focused on N54 motors. OP's is a N55 which has been recognized as not having as severe an issue with carbon build up. Matticus had a thread where a friend of his had the walnut service done on his N55. From what I recall from the pics, there wasn't much of an issue.

[JM98]

Originally Posted by zx10guy

That thread is focused on N54 motors. OP's is a N55 which has been recognized as not having as severe an issue with carbon build up. Matticus had a thread where a friend of his had the walnut service done on his N55. From what I recall from the pics, there wasn't much of an issue.

I keep forgetting 135i's had the N55 lol. Thanks for catching that. OP probably just needs basic maintenance.

[N54Yankee]

Had my N54 blasted at about 60k and went into garage to see the before and after results and it was a big difference, when done the ports looked practically new when before there was definitely a buildup. Driving home I noticed an small improvement but not as much as I thought there would be. My opinion was likely skewed because just the week before I had installed a Cobb tune and wasn’t as familiar with the newly acquired power so didn’t have a good reference to base the comparison on. Looking at the before and after it’s clear that flow is improved substantially.