Common BMW N47 Engine Problems: Causes and Solutions

By Nick Marchenko, PhD

The BMW N47 is an in-line four-cylinder diesel engine introduced in 2007, succeeding the M47, which was first used in the BMW 1 Series (E87). It was soon implemented in the BMW 5 Series (E60) and BMW 3 Series (E90) as well. The less powerful variants are equipped with a single turbocharger (VTG charger), while the more powerful ones, starting from 150 kW (201 hp), have twin turbochargers.

Cars Equipped With BMW N47 Engine

BMW N47 Engine Problems

The N47 has suffered from a number of problems since its market launch, which were somewhat mitigated but never fully eliminated by the end of production. Below, we explore the most common weaknesses of this engine.

Stretched Timing Chain

The N47's timing chain is known to stretch prematurely, leading to catastrophic engine failure. This is typically due to a defective chain tensioner, and the wear can be accelerated by delayed or skipped oil changes. Engines from the early production years (approximately 2007 to 2009) are particularly affected, as crankshafts were installed with sharp-edged sprockets that facilitated the elongation or tearing of the timing chain.

When inspecting the vehicle, it is essential to listen for clacking or rattling noises at engine start (preferably cold) and during load changes. If this is the case, the chain is likely already stretched, and engine damage may be imminent.

Noise from the Chain Drive

Another phenomenon reported by many owners is grinding or ticking noises at idle (easily heard in this YouTube video). The noise can also be noticed while driving, usually between 1,500 and 2,000 rpm. This generally indicates a problem with the timing chain, but the manufacturer states that in younger models, it's merely a "comfort issue."

Problems with the EGR Cooler

A large number of BMW vehicles with the N47 engine were recalled due to a leaky EGR cooler that could allow glycol to escape. When glycol encounters soot particles at high temperatures, this can lead to an increased fire risk. Vehicles from 2010 onwards are affected.

Carbon Buildup on the Injectors and EGR Valve

Carbon buildup on the injectors and in the EGR valve can lead to costly repairs, particularly in diesel vehicles. To prevent or at least delay these, the use of cleaning fuel additives, added at regular intervals when refueling, is recommended.

BMW N47 Engine Tech Specs

Conclusion

Caution is advised when purchasing a BMW with the N47 diesel engine. The latest production years may be conditionally recommendable, but even the most recent engines of this series have not been spared the timing chain problems. A well-maintained service history with BMW is almost mandatory to hope for goodwill in case of problems. Consideration should also be given to taking out a repair cost insurance.

Nick Marchenko, PhD

Industrial Engineer & Automotive Content Specialist

Nick writes in-depth guides on car clubs, engine specs, vehicle ownership, and modifications, combining engineering knowledge with automotive passion.

Full profile → LinkedIn →