Power Loss

Hi I have Freelander 2 TDi 4 diesel 54 plate, recently I have had a whole catalogue of problems. New alternator, new injector rods and replaced a split in the turbo hose. Car has been running well for a month or so.
Yesterday I felt a couple of jolts on the motorway and started to hope they would pass. However, today the car has been jolting when in 3rd and 4th and is losing power gradually. When the turbo hose was repaired, I was advised that the intercooler had a leak but that it was only moist and not to worry about. Could it be the intercooler causing this ?

A leaking part of the boost system simply means less power and potentially black smoke production. Jolting (possible dropping out?) is unusual and needs interesting.