N47 engine reliability: strengths, watch-outs, and known issues

Early engines had low timing chain lifespan: guides wore out, chains stretched, and sharp teeth on the crankshaft sprocket accelerated the process. On updated N47TU or N47N engines, most weak points were eliminated.

The aluminum block was initially designed without a special safety margin, and severe overheating could cause cracks between the second and third cylinders. With the update, the block was reinforced and such problems almost ceased.

All engines in this series are equipped with a reliable Bosch Common Rail fuel system, but powerful versions with piezo injectors are quite demanding on fuel quality. Also, avoid driving with an empty tank, as the high-pressure pump may suck in air and start producing metal shavings.

Almost all versions of these engines are equipped with swirl flaps in the intake. They not only get dirty quickly but can also break off and fall into the cylinders. However, unlike the predecessor, they are plastic and cause no particular harm.

The turbos themselves are very reliable and last a long time with frequent oil changes. The main engine problems are related to the intricate system of dozens of hoses and tubes; any crack forces extensive work to find an air leak.

Weak points also include short-lived gaskets and seals, valve cover, thermostat, crankshaft damper pulley, and glow plug relay. Additionally, rapid contamination of the intake, DPF, and EGR causes many problems.