The Most Common BMW N43 Engine Problems

Do you have a BMW with an N43 engine under the bonnet? If so, you may be facing some common issues from time to time. You may be on the lookout for the causes, symptoms, and solutions to the problems. After reading this article, your search will come to an end as you will be able to diagnose and resolve the issues yourself. Read on to know more.

1. Timing Chain Issue

A timing chain failure may result in the complete destruction of the engine. What happens is that the timing chain is responsible for running the entire engine system. If it breaks down, it may cause considerable damage to the engine. Therefore, if you have issues with the timing chain, make sure you get it replaced immediately.


Rough idling
Strange noises
Engine misfires
Engine failure
Metal shavings
Check engine light


You may have to go for an engine overhaul if your engine is severely damaged due to the broken timing chain. The cost of an engine rebuild will be between $700 and $850. So, keeping an eye on the timing chain is vital if you want to be on the safe side.

2. NOx Sensor Error

When the manufacturer launched N43 and N53 engines, they added more complex technology into these engines. One of such components is the NOx sensor. The role of this sensor is to monitor the nitrogen oxide emissions by the engine for compliance with regulations.

Symptoms of BMW N43 NOx sensor error

Given below is the list of some common symptoms of the error of this sensor:

Higher fuel consumption
Unstable idling
Engine warning lights

The solution to the NOx sensor error

There are three possible solutions to these problems: sensor replacement or deleting the long-term adaptations

There are two possible and effortless solutions for NOx sensor errors. These are as follows:

3. Fuel Injectors Problems

In winter, most engine problems occur due to a drop in temperature. This common problem happens due to fuel injector problems. A failing fuel injector may cause a lot of other complications. Also, these problems may cause a complete engine failure if not fixed in time.

Symptoms of faulty fuel injector
If you notice any of these signs, you should take timely actions in order to prevent the problem from getting worse:

Stuttered start and hiccup sounds
Smoke from the tailpipe
Foul odor
Rough drive
Idling issues
Engine knocks

Solution for fuel injector issues

If you have one or more of the above-mentioned symptoms, we suggest that you go for the fuel injector replacement. This will fix the problem and allow you to experience a smooth drive once again.

Aside from this, you will enjoy better fuel economy due to the proper working of the injectors. After you have replaced the components, your car engine will start instantly and the odor will be gone.


Long story short, as far as build quality is concerned, the engine of a BMW N43 is exceptional. However, you need to fix some problems from time to time. Therefore, if you have made your mind to purchase this vehicle, we suggest that you prepare yourself to deal with these issues. After all, you don’t want to end up ruining your vehicle.

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