Its been a while since I have had the opportunity to post a case study, needless to say we have had many interesting cases pass through the workshop. The latest was a 2016 Citroen DS3 the customer reported a severe lack of power accompanied by illumination of the M.I.L I began with a diagnostic check which revealed an error code P0011 (camshaft position A over advanced)
Position A refers to the inlet camshaft, this means the PCM is reporting an irregularity with the inlet variable timing control. The variable timing deviation (both inlet and exhaust) is controlled by two solenoids located on the side of the cylinder head which diverts engine oil under pressure into the relative camshaft phaser to advance and retard the valve timing.
The first thing I noticed with this vehicle was the poor service history. in fact the service service display was indicating it was almost 2000 mls overdue! To prevent damage to the camshaft phasers each solenoid has a gauze filter so I thought this was a good place to start, Upon removal it was soon apparent that the gauze was blocked (see photo)
I cleaned both solenoids and refitted back on the engine, a further diagnostic check revealed correct functionality of the VVT system and the error code could now be erased. I think the lesson here is to have your vehicle serviced in accordance with manufacturers recommendations.