bad judder when driving

[mirach]

hi to all
I have recently bought my other half a 54plate x type diesel 2.0ltr not the best of them but cheap (or maybe not) the car has a really bad judder from the front,
we have put 4 new tyres on and had them balanced -all good, judder still present
I then took the car for an mot and told garage about the problem so we gave it a serious check over and found some wear on n/s driveshaft, new one fitted and hey presto! NO DIFFERENT
I have spoken to the previous owner who reckons it is a hole in the intercooler or intercooler pipe ,there is quite a lot of black smoke when you boot it.
mrs really likes the car but need to sort this!
any ideas please