P0011 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.

In these engines the oil pump is adjustable, and the factory setting deliberately keeps the oil pressure low at low revs to reduce the drag of driving it. At low revs the stock pump works at around 1.8 bar, up to 2 bar at most. With a warm engine at idle this can fall further, and values below 1 bar have been reported. The camshaft adjusters feel the low pressure first, because the oil pressure itself is what holds the adjuster in place: this is where the clacking noise heard at idle comes from. The chain tensioner follows, which the same pressure tensions, and the timing chain therefore wears faster. The reference values for this engine family are 2 bar at idle, 3 bar at 2,000 rpm and 4.5 bar at 4,000 rpm. The turbocharger and the camshaft are lubricated from the same circuit. A strengthened oil pump raises the idle pressure by about 20 per cent. Repairing the pump costs between 800 and 2,800 euro, and replacing a worn chain is a further 1,200 to 3,500 euro.

Opel's 1.4 litre turbo petrol engine (A14NET, later B14NET) is fitted to the Astra J, Insignia A, Zafira C and Mokka.

The 1.6 naturally aspirated petrol engines of the Astra H (Z16XEP, Z16XE1, Z16XER) run a timing belt, not a chain. The replacement interval is 150,000 km or 10 years, whichever comes first.

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.

The valvetrain of the three cylinder 1.2 runs on a chain instead of a belt. Both the chain and the tensioner are undersized for this engine. The chain starts stretching as early as 60,000 to 80,000 km, and the tensioner loses its pressure. The sign is a rattling noise audible for a few seconds on a cold start. The earliest BME has the weakest tensioner, and the BZG is structurally the same. If the chain jumps, the engine is badly damaged inside, and the repair is typically an engine rebuild. A low oil level speeds the wear up enormously: the tensioner is driven by oil pressure. That is why the oil level has to be checked every 1,000 km on this engine.

With the 2008 EA888 VW switched from a belt to a chain, and the tensioner of the first two generations turned out weak: as the ratchet mechanism ages it does not hold its position when the engine stops and the oil pressure disappears. The oil drains overnight and the chain goes slack. The symptom looks harmless for a long time (a short, few second rattle on a cold start as the chain slaps the guide rail), and then one day it jumps, and the engine is badly damaged inside. From then on the repair is a cylinder head or an engine rebuild. Around 2012 the maker was already fitting an improved tensioner; on the old one only replacement helps, not monitoring the noise.

The check valve is missing from the oil supply of the timing chain tensioner. With the engine stopped the oil drains out of the passage, so at start-up the tensioner does not get pressure straight away, and over time that wears it out. On early production examples it appears from as little as 60 000 kilometres.

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.