Common BMW N20 Engine Problems - Models, Causes, Solutions

By Nick Marchenko, PhD

The BMW N20 is a four-cylinder gasoline engine that was produced from 2011 to 2017, replacing the six-cylinder N52 and N53 engines. The engine made its debut in the X1 E84, shortly followed by its implementation in other models, such as the 3 Series F30 or the 1 Series F20.

Weaknesses of the BMW N20

Even though the N20 is more reliable compared to older four-cylinder generations, there are still enough weaknesses that can cause issues for an unfortunate owner. The following are the most common problems.

Stretched Timing Chain

While the problems related to the chain drive have been somewhat mitigated, it still remains a weak point. Once the timing chain stretches, the timing does not match anymore, which in the worst case can lead to catastrophic engine damage. The wear process is further accelerated by late or missing oil changes and frequent short-distance driving.

When inspecting the vehicle, care must be taken to see if there are clacking or rattling noises at engine start (best when cold) and during load changes. If this is the case, the chain is likely already elongated, and engine damage could be imminent.

Oil Pump Failure

The N20 has an upper timing chain that regulates the valve train, and a lower one that drives the oil pump. The latter is also prone to elongation like the upper and can even break, inevitably leading to the failure of the oil pump. As a result, the engine is no longer supplied with oil and suffers total damage. Primarily, units from the first production years are affected.

Problems with the Brake Booster

A faulty camshaft driving a vacuum pump can result in the brake booster no longer being supplied with oil. A classic symptom for this is an increasingly stiff brake pedal, although the manufacturer emphasized that a complete failure of the braking system is not to be feared. The associated recall garage visit can take up to two hours.

Carbon Buildup in the Intake Tract and on the Valves

Due to direct gasoline injection, the N20 will have to deal with coked injectors and carbon deposits in the intake tract. To at least delay the resulting problems (loss of power, higher consumption, etc.), it is recommended to proactively use cleaning fuel additives, added at regular intervals when refueling.

BMW N20 Engine Technical Specs

Conclusion

The N20 could not completely rid itself of the problems of its predecessors. Since older models may be particularly at risk of running dry, it is advisable to invest more money and opt for a newer model if possible. For peace of mind, one might also do well to consider a BMW from the in-house 'Premium Selection'.

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.

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