[luxe91]

Hi All. I have a 2006 E91 with a M47N2 engine. 110k miles. Two of the four swirl flaps broke off and fell into the intake port where they were partially ground down by the valves.

The only things that went through the combustion chamber were 3 of the screws/rivets holding the flaps together and metal particles.

- Piston 4 has visible damage.
- The head has #4 damage and has not been tested for seal yet
- The injectors and glow plugs appear ok
- I suspect there are metal particles sitting on top of (maybe even between) the piston rings which may score the cylinder walls
- Not sure right now on damage to turbo or the DPF (needs a cleaning anyway)


I am looking for advise on next steps. Can I build this back up with fresh gaskets/head bolts? Or am I looking at a rebuild - perhaps replacing all piston rings, piston 4 and have the valves reseated?
I have not done such as job before thus the questions. Also very limited on garage space to pull the motor out. Otherwise I feel competent to handle the task.

I live near Germany so have access to reasonably priced parts for this car. Lot of car breaker supply on eBay.de.

[And yes I know it was daft to not take out the flaps years ago. When I bought the car in 2012 there were no cases of failure in this year as I understood but turned out I had the 22mm weak flaps.
In running condition the car is worth 4-5k euro and I am now ready to move on to a solution after much regret].