I have a Ford Mondeo 2007 MKiii. It has developed a strange fault. Whilst driving and turning steering to right it twitches a little and then ok. So every time slight moving my steering to right it twitches for second or so. This is really weird and driving me crazy. I took it to the mechanic and he was unable to replicate the issue. The steering is slightly heavy to use as well.

Any help would be much appreciated.

Many thanks.