Ford Focus producing blue and black smoke on start up

[webbcat]

My parent's Ford Focus, bought about 4 years ago (2000) with a diesel engine, has recently started emiting a bluey black smoke when they start the car. Their garage can not find out what is causing the problem, even after consulting diesel engine specialists. Has anyone else had this problem with a Ford Focus? And if so did you find the cause of the problem?

[John C]

Have the glow plugs been renewed? The smoke is caused by over fuelling or poor combustion on startup and the most common cause is the glowplugs not working or working innefficiently. If they've been renewed they may have been changed for cooler plugs (but Ford OEM should be ok).

The only other causes are a pump fault or poor compression - both expensive to fix and it's easier to put up with the smoke to be honest!

JC