I recently had the engine replaced on my 2003 Focus 1.8 TDCi after a bottom end failure. I recently got it back from the mechanic and when I start it after it has been sitting all night or day, lots of blue smoke comes out for ages after starting up. The car also runs very lumpy too. Eventually the smoke clears and the car runs great.

What could be the problem and is it an expensive fix as I am sick of spending money on this car?

 

could be lots of things. id take it back to get it checked out.

 

I too have a similar problem with mine though the smoke is more white than blue. The poor running is there with hesitation and a misfire but once it's warmed up a little is absolutely fine. Would love some pointers to start looking at. Obviously temp related and it does take a while to heat up,more so than my previous 1.6 petrol or other cars I use. So was thinking of a thermostat change first and engine temp sensor. I'm told the brief white smoke or white smoke for a minute or too is normal nut I can't think this is right.
Any pointers towards a common problem would be much appreciated.