Out of all the systems that make the car work, the intake system is among the most overlooked. Your intake is just as important as any of the more frequently discussed parts of your engine. Even the slightest intake issue will have a significant effect on the performance of your car.

As you may know, engines require a precise mix of air and fuel in order to sustain combustion. The amount of air that enters the engine, as well as its timing, is crucial for a proper fuel/air mix.

The BMW N20 is a turbocharged engine that replaced the N52/N53 engines, which were naturally aspirated. The outgoing naturally aspirated engines were very reliable, and the N20 engine had some big shoes to fill. However, just like any other engine, it has its issues. One of them is the N20 air intake hose.

Article updated on 01/14/22. Original publishing date 10/24/19. 

Is The BMW N20 Air Intake Hose Really That Fragile?

The air intake hose has two primary functions — to send the exact right amount of air to the engine and to filter that same air ensuring that no debris reaches the engine.

Certain engines are more sensitive than others in this regard. While BMW generally builds reliable engines, they need to be maintained properly and regularly with high-quality OEM parts. The same applies to the N20’s intake system. Even the smallest issue with the N20 air intake hose can cause a faster or rough idle. A larger crack or bad fitment can cause more serious issues than just a rough idle.

The BMW’s N20 engine produces more heat simply because of its turbocharged nature. With the excess heat radiating from the turbo system, plastic parts in close proximity are more prone to wear. The N20 air intake hose is made out of plastic, and it’s close to the turbo. The frequent hot and cold cycles make them become fragile over time. As a result, you could see cracks appearing in certain weak spots.

This issue is often so severe that changing the air filter can be a highly dangerous procedure. The process of opening the air box, and swapping the filter media is enough to cause cracks on the high-stress areas of the intake.

Symptoms Of a Bad N20 Air Intake Hose

The N20 air intake hose is the connection between the air filter and the air intake manifold located on the engine. The air filter is the first part that takes in the air required for the engine to properly operate while stopping dust and debris from reaching the intake manifold.

The air intake hose is the bridge between these two parts, and it needs to be in perfect condition to provide the engine with the required air to put out all the power it has. Unfortunately, the air intake hose is a part that can fail, and when it does, the amount of air the computer thinks is entering the engine no longer matches the actual amount of air that enters the cylinders. At that time, you’ll start noticing some issues.

Rough Idle

The first symptom of a faulty N20 air intake hose is a rough idle. BMW is known to be sensitive regarding the air-fuel ratio and when the sensor in the air intake hose has a faulty reading, it can cause a series of symptoms. Rough idle is the smallest issue because the engine can stall from a faulty N20 air intake hose.

Hissing Noise

Another symptom of a faulty or cracked N20 air intake hose is a hissing or whistling sound coming from the engine bay. These sounds are a clear sign that air is leaking out somewhere on the air intake. The harder you push the engine, the louder the noise will be.

If the crack on the N20 air intake hose is large enough, there’s also a possibility of the check engine light to show on your dashboard. Because cracks can be in hard-to-see places, it’s important to run diagnostics and find the issue as soon as possible.

The Issues A Faulty N20 Air Intake Hose Can Cause

Although it’s unlikely that your car will break down due to a faulty air intake hose, there are issues it can cause over time.

It might not happen suddenly, but a faulty or cracked N20 air intake hose can cause enough dust and debris to reach the engine and wear out internal parts that can cause the engine to stall. Allowing such a small issue to cause irreversible damage is something you don’t want to do.

Lean or Rich Condition

If the air-fuel mixture isn’t perfect, the engine might run lean. A lean condition is not something you want to tolerate for too long as it can cause all kinds of issues with the engine. In some cases, the engine could run rich as the ECU fights to compensate for the unaccounted air. Either of these is considered dangerous for your engine and should be addressed as soon as possible.

Increased Fuel Consumption

Another issue caused by a bad N20 air intake hose is increased fuel consumption. It can start with a small increase in consumption, but as the crack gets worse, the more fuel your car will consume. You’ll also notice a lot less power coming at the wheels. A bad air to fuel ratio will cause the engine to put out a lot less power than you’re used to.

Can You Fix a Faulty Intake Hose?

While fixing plastic parts, especially ones that are as essential as an air intake hose is possible, it’s not something we can recommend. The main reason is that patching the hole in your intake won’t change the fact that it has gone brittle. If it cracked once, there’s a good chance it will crack again. Instead, we recommend replacing your factory hose with a Genuine BMW N20 air intake hose (Part No. 13717605638) as that will ensure a permanent fix to your problems. This particular hose fits the following models.

Application list:

2012 BMW 228i 320i 328i 428i 528i Z4 X1 X3 X5

2013 BMW 228i 320i 328i 428i 528i Z4 X1 X3 X5

2014 BMW 228i 320i 328i 428i 528i Z4 X1 X3 X5

2015 BMW 228i 320i 328i 428i 528i Z4 X1 X3 X5

2016 BMW 228i 320i 328i 428i 528i Z4 X1 X3 X5

Use Quality Parts to Service Your BMW N20

The BMW N20 engine, just like any other Bimmer engine, works best when it’s fed good fuel and quality parts. The only way to keep this motor running reliably is to use Genuine BMW parts or quality OEM. We happen to be one of the largest retailers of both. Head over to our online store, input your car’s details in our navigation tool, and you’ll find everything you need to fix your N20.