Hi and welcome to just answer.
what colour smoke is omitted ?
do have a loss of power?
no loss of power but juddering at 60 ish
these engines do suffer with this issue and the powerplant is straight out of a ford mondeo .
the most common faults are a turbo pipe that has a split and the exhaust gas recirculation valve .
the split pipe syndrome is normally the short pipe that sits around the left hand side of the rocker cover I have replaced hundreds of these over the years.
Have you had any diagnostics done and any fault codes stored?
is the smoke black or blue in colour?
any warning lights on dash when this occurs?