I have recently bought a new Citroen C4 BlueHDI 100 which I am very satisfied with. I recently noticed on a long journey a heavy feeling to the steering intermittently which I thought might be a puncture or similar. I continued on my Journey and upon reaching destination pumped all tyres, none of which had lost more than a PSI from manufacturer spec.

I have since noticed the problem become ever more frequent. I have also noted that the steering fails to self-centre without my assistance, sometimes allowing me to travel at 8-9mph without any corrective input without hands on the wheel.

My suspicion is this is a power steering fault (I believe the older C4s were prone to them). Is there anything else it could be?