If this wasn't a modern common rail DI engine I would say faulty glow plugs but generally these engines will start OK without them. The white smoke is unburnt fuel due to incomplete combustion, this was a common fault on IDI engines.

It could be that your compression is down so it does need the glowplugs so I think that would be the first place to start. If you are thinking of checking them yourself, shout and I will tell you how.

Compression is to do with bore/piston wear or valves not correctly seating but is not all that common now unless the engine has been abused. It could possibly be an injector problem but not one I have come across. A trip to a diesel specialist would be the best thing, they usually know what they are doing and are cheaper than a garage.

White smoke sounds like unburned diesel.

The fact it occurs during cold starting sounds like glow plug failure or lack of compression. The latter would be unusual though unless the engine has really high miles or has been neglected or damaged. May be worth getting the fault codes read first to see if anything is flagged up before embarking on a solution by random replacement of parts?

Lack of compression could be measured using the glow plug holes and turning the engine over with a compression tester screwed into each hole in turn.

If it is a glow plug issue then it could be one or more plugs has failed OR that the plugs are not seeing a current, which could be a wiring issue, or a defective relay (first things to check before assuming plugs are kaput).

I guess a leaking injector could dump diesel into the cylinders when the engine was turned off, but this should create smoke which quickly clears and does not persist as you describe.

I'd say check glow plugs are receiving a current and, if so, get them tested outside the engine to see if they are still working or get them changed.

SO...I have had the glow plugs tested but if I am being honest, I am not 100% confident.

The garage said they got to the plugs and tested them whilst they were still attached and they all are fine........I asked about the wireing and got...We only deal with mechanical, not the electrics!!

Arrrrrr!!!!

I remmeber being quoted a silly price when my Focus TDCi was in for investigation of a possible injector issue. I'd recommend taking the car to an independent local diesel specialist (e.g: A Bosch or Delphi agent) and get them to test the injectors to see if any actually need replacing.

If so, they might be able to get some for you cheaper than Ford or else recondition them if that's possible. New injectors need to be coded to the engine, however, which might require a return trip to Ford, but shouldn't cost much.