[Lowline]

Thanks Mike, the iat is a bit of a red herring I think. When I out the obd reader on live data it shows what I would be expecting, today it was showing about 12 degree C. I agree about the chain but would it not throw up a fault code. Cheers Steve

 

[Lowline]

Another thing that was strage today was that even though the coolant temperature reached 97degrees on the live data, the fan didn't cut in... I checked the fuse which was OK and even jumped the relay to make it turn on, which it did. I dont think theres a specific switch on these, I would have thought the ECU tells the fan to turn on using the data from the coolant temperature sensor.
If Im wrong and theres another sensor that switches the fan on maybe this is all linked and the ecu thinks the engines cold. I got steady readings of 1.5 volts from the pre cat O2 sensor and reading of 0.75 in the post cat sensor. Does this sound correct...?
Thanks for your help everyones its very much appreciated.

 

[AsdaJnr]

Can't help you with the voltages for your cat sensors, sorry.

However seeing as your at the point of grasping straws, I was talking to a chap today about this. He had (past tense) a 2009 Mini Cooper with a stalling issue and his garage changed the purge valve which cured his issue. I don't have clue if yours has one and if it does where it's located?...

 

[Lowline]

Thanks, I unplugged the valve tonight and blanked the input on the inlet manifold, unfortunately ot made no difference, worth a try though.
Im usure about the o2 sensor readings that I postage yesterday. Some searches say the voltage in the pre cat shouldnt go above 1v and another site said the R56 runs with the voltage about 1.5. I dont want to blindly change things without trying to diagnose the fault first. I think I getting to the end of my knowledge.
Has anyone had this kind of fault caused by a streched chain without any fault codes..? Thanks for your help everyone.