Since buying my Cooper S at 49k the idle has been fairly rattly, almost like a diesel except I drove an Cooper SD and it was smoother!
ever since I've had it I've always used V power shell petrol and I've flushed the engine with redex and gave it a new oil filter an proper oil!
I thought maybe it was the lower engine mount so I bought a poly bush one (if it was due to a bad engine mount then I would've been okay to cope with vibrations through the poly bush) but the engine mount was perfect. replaced anyway and literally NO difference at all to the idle feel in cabin.
It definitely gets worse when the AC is on, feels like a town bus!
The only thing I can think it could be is spark plugs, I've heard bmw sometimes mixes them up between champion an NGK which can cause a few issues (is this even true?)
if not, what else shall I look out for? car does seem to use a lot of fuel, 20mpg mostly! though I do push it a fair amount.
ever since I've had it I've always used V power shell petrol and I've flushed the engine with redex and gave it a new oil filter an proper oil!
I thought maybe it was the lower engine mount so I bought a poly bush one (if it was due to a bad engine mount then I would've been okay to cope with vibrations through the poly bush) but the engine mount was perfect. replaced anyway and literally NO difference at all to the idle feel in cabin.
It definitely gets worse when the AC is on, feels like a town bus!
The only thing I can think it could be is spark plugs, I've heard bmw sometimes mixes them up between champion an NGK which can cause a few issues (is this even true?)
if not, what else shall I look out for? car does seem to use a lot of fuel, 20mpg mostly! though I do push it a fair amount.