P0012 fault code.

The factory timing chain is 7 millimetres wide, and that is too little for this engine: the chain wears and stretches prematurely. The repair replaces it with an 8 millimetre chain. In a bad case the chain skips teeth or snaps, and then the valves and the cylinder head are seriously damaged. The early sign is a metallic knocking or rattling noise at idle when cold, together with power that slowly fades. In the fault memory, codes pointing to the relative position of the crankshaft and the camshaft appear: P0011, P0012, P0016, P0017 and P0018. The wear starts from 70,000 km. The maker issued a recall and a retroactive goodwill programme for it. The range is the engines built between October 2017 and January 2023, across five brands: Opel, Citroen, Peugeot, DS and Fiat. In Germany 141,700 cars were called in, and the workshops judge the condition of the chain by the noise of the engine. The warranty was extended to 10 years or 240,000 km, provided the servicing was done to the factory specification by a specialist workshop. Anyone who paid for the chain replacement themselves between January 2023 and June 2025 can claim the cost back, material and labour together. For used cars there is also a separate certificate confirming that the benefit passes to the next owner. The chain replacement on its own is between 1,200 and 2,000 euro. The specified oil is not a formality here: the engines covered by the recall need the lubricant to the FPW9.55535/03 specification, because its anti-wear additives slow the wear of the chain.

Four aluminium bolts hold the housing of the variable valve timing (VANOS). On some six cylinder engines built between late 2009 and mid 2012 these bolts loosen over time, and can also break.

VANOS adjusts the position of the camshaft with the pressure of the engine oil, and a solenoid valve metres that pressure. The valve sits in the oil circuit, and a fine filter screen protects the spool inside it from larger particles. That screen clogs with carbon and deposits: less oil flows through, and VANOS then adjusts late or does not move at all. The symptoms are a rough idle, rough running, a lack of torque at low revs and higher fuel consumption, because the valve timing is off. A short metallic clacking can also come on a cold start and goes quiet after 10 to 20 seconds. The engine warning light comes on with a camshaft fault code, and depending on the severity the engine control unit switches to limp mode. The fault code narrows down the cause. P0010 and P0013 typically mean the solenoid valve itself, that is a circuit fault or reduced oil flow through the clogged screen. P0011 and P0014 point more to a mechanical cause: a stretched timing chain or a worn adjuster. P0012 and P0015 report late camshaft control, whose common cause is slow pressure build-up at the adjuster, so again the dirty valve. The valve itself is a small part, between 50 and 120 euro, and with a clean screen cleaning is often enough; replacing the whole adjuster, by contrast, is a four-figure job. The reported repairs ran between 80 and 1,200 euro, depending on whether cleaning is enough and how many valves are affected. The main cause of the screen clogging is a stretched oil change interval and carbon-laden oil.

This is the most common N54 fault, and it affects early N55 engines too. The pump is a two part design: fuel goes into one half and lubricating oil into the other, and the sealing ring separating them ages over time. That is what drops the pressure.