Hi, I recently purchased a 2008 159 1.9jtdm which has since collection had an issue no one has yet been able to diagnose and rectify. Symptoms are as below:
If car is fully cold (ie stood overnight etc) starting is no problem (it actually seems to start quicker if outside air temp is lower)
When car is fully warmed up (90°C showing on dash) restart is again no problem.
Starting is a problem when car has had a heat cycle, but is neither hot nor cold. Examples are after a cold start, drive ½ mile to shop and park up for a few minutes, or drive car until warm then leave to sit for 2-3 hours.
When attempting a restart the engine spins over on the starter at what appears to be an acceptable pace, not suggesting poor battery or starter performance.
Engine will continue to spin over and gradually begin bit by bit to catch (as in it seems like first one then two then three cylinders come into life before eventually starting to run normally on all four)
Fuel consumption even with VERY careful motorway driving only just exceeds 30mpg. Average tends to be around 27mpg around town without traffic!
Car has so far had replaced all injectors and the engine coolant temp sensor, both made no difference. The supplying dealer's "diesel specialist" suggests next replacing the crank sensor, but I'm not convinced... Any better ideas, advice or suggestions greatly appreciated