I have a 2.5 tdi V6 that takes about 30 seconds to start 1st thing in the morning..... once warm runs like a dream and starts ok. Only happens when left over night... can anyone help???

My first guess is that your starting motor is starting to go, pardon the pun. This is pretty much the first step.

 

Glen.

Hi, i would guess that the glow plug pre warmers are shot. If you turn the ignition on and let the glow plug light go out and then switch it off and put the glowplugs back on again i bet it starts easier.

 

 

Assuming its manual you could also depress the clutch to remove the drag of the gearbox as well.

I agree with Mark on the glow plugs.  Only other thing that commonly causes poor cold starts on 2.5 TDI is when it has had a cam belt change and the commencement of injection on the distributor injection pump has not been set up correctly.  Check the glow plugs first though