Cayenne v6 2008 misfiring on#5

[olivier]

Hello

The wife s Cayenne Is misfiring on cyl 5 when idling or coming to a stop on l'y when warm

We turn thé engine off and restart and it Is okay until we come to another stop

Car Is a 2008 180k km

Plugs ,coil , #5 injector , chains ,tensionner were changed

Leaked down numbers were not great on 2 bank ( valves were heavyly carbon cloagged)

Removed thé head and rebuild it

Still the same story

I am really starting to hate those vr6

Any help would be greatly appreciated

Merci

[RFM]

There is specific locking tool used to adjust the timing? Are the vacuum operated butterfly valves inside the intake manifold, and intake ports not damaged, blocked or clogged? Are the valves cleaned and grinding  properly in their seats, valve spring(s) not weak or broken? Compression test done? No air leak at cyl. 5? DTC P0305 should be there for sure, anny other error codes? A diagnostic tool could help a lot as well as an emission test (HC-CO-CO²-O²) at idle and at 3.000 RPM. There are many possibilities, into the engine block itself at a VR6.