CDLG engine faults.

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 crankcase breather carries the vapour that forms inside the engine back to the intake, and a rubber membrane regulates the pressure. Oil and heat harden this membrane until it tears, and from then on the intake draws air through the hole in it. The engine control unit does not measure that air, so the mixture goes wrong: the engine shakes at idle, stumbles when accelerating, and the fault memory gets P2279 for an intake system leak. In the other direction oil starts towards the intake, which leaves an oily film in the intercooler and on the intake pipe and speeds up the carbon build-up on the intake valves. The audible sign is a whistling or hissing noise from the engine bay, loudest at idle. The tear is reported between 60,000 and 90,000 km. On the first and second generation the breather is a separately replaceable valve (factory number 06H 103 495 AK) and costs between 80 and 400 euro; from the third generation it is built into the cam cover, so there the cover is replaced. The maker issued three versions up to 2016, and fitting the pressure variant that does not belong to the engine brings the same symptom back.