I wonder why these Cooper S's need decoking????

__________________

Yes it was covered under warranty. Took 3 days to do and involved the engine being stripped down and rebuilt with new gaskets and seals (had a new head gasket for example).

Not just the S's suffer from it from what the dealer told me: I thought it was just the S's but aparently not...

I believe its because oil vapour is fed back into the intake manifold to be burnt to keep emissions down but this builds up on the inlet valves and can cause them to stick - I think this is what had happened to mine to give it the miss and make it a bit rough.

The dealer told me that the car doesnt like sitting in traffic and needs to be driven hard to keep it clear of deposits - not sure how much that would help TBH though...

__________________
Back in the fold... but being tempted out again...

Its true unfortunately. The oil isnt being lost past the piston rings or valve stem seals, but its going out the oil breather and though the engine that way!

This is the inside of one of my intake hoses, being blue silicon you can see how much oil has past through it and stuck to it in the 18 months they've been fitted!

__________________

I bet if I look in mine I'll find the same. Wish I could mine done under warranty. Big bills sadly, going to have to live with it.