I have a 2006 Grand Voyager 2.8CRD UK Specification.

The battery is fine, however when i turn engine with key it now takes several turns for the engine to fire up - progressively worse over last 2 weeks - can u help?
Pup

 

Is your starter motor turning in normal speed or slowly.. like theres not enough power in a battery? If its normal maybe its a fuel issue... Have u checked your spark plugs?

 

starter motor is normal - battery is fine - 3 months old with 5 year guarantee. The engine is diesel for reference.

 

In the old days of indirect injection diesels I would have said check each glow-plug by disconnecting it and wiring a test-lamp between battery +ve. and glow-plug top. It was nearly always the case that one was o/c. A heavy current test lamp such as an old headlight with some wires soldered on is best.
But modern diesels start a lot easier because they are DIRECT injection; however, it costs nothing to check the glow plugs. If one is o/c, only use Bosch as a replacement -- they last a long time. Otherwise you'll have to look in the fuel supply system, and there's plenty here on this site about that.

Leedsman.

 

There could be some ignition switch problem.You need to check it and secondly the humidity might be a reason.

 

I would guess the glowplug answer is close. I had one that the end blew off but I never knew why. The glowplugs are not easy to get to although they are at the front (side) of the engine with two of them hidden behing the inlet manifold. However the glowplugs have a have a connector near the alternator - it is not hard to find and you can test resistance there easily enough. Be aware though that you get the right replacement as they come in different voltages. The Jeep with the same engine has different glowplugs!