Hi,folks a little bit of help and advice please,I have a 2003 2.0hdi bought last year with 56000 on the clock,the first owner only put 26000 until parting with it in late 2012, the rest(now 67000) by the second owner and myself.I am having an oil filter/oil change next week as it has done 12000 since last done is there anything else I should renew ie fuel or air filter as well?Also when the engine is at idle the engine runs at just the wrong side of smooth(if that makes sense) at about 8/900 rpm,just touch the pedal and take it up to near 1000 rpm and it is as smooth as silk,is this just a characteristic of the HDI engine,can it be adjusted or should it be left alone? and lastly the air con has stopped working the light does not come on nor on the right hand button(cabin airflow?) I have checked the glovebox fuse can,t see a problem any thoughts?thanks in advance,Steve.