A Guide to the 2012-2016 BMW 528i Engine Crankcase Breather Hose
Address rough idling and check engine lights by understanding this critical N20 engine component.
- A failing breather hose on the 2012-2016 BMW 528i is a common issue that causes vacuum leaks.
- Symptoms include a rough idle, whistling noises, and a Check Engine Light with lean code P0171.
- Replacement is simple and can be done by most DIYers in under an hour, preventing more complex issues.
- High-quality aftermarket brands like CRP/Rein offer a reliable, cost-effective alternative to the more expensive genuine BMW part.
Understanding the Crankcase Breather Hose in Your 528i
The 2012-2016 BMW 528i with the N20 engine relies on a precisely managed crankcase ventilation system to maintain performance and longevity. The crankcase breather hose is a simple but vital plastic tube that routes pressurized gases out of the engine block and into the turbo inlet pipe. Over time, constant exposure to engine heat makes this plastic hose brittle, leading to cracks and eventual failure. When it fails, it creates a vacuum leak, which can cause a variety of noticeable problems.
Symptoms of a Failing Breather Hose
A cracked or broken breather hose will disrupt the air-fuel mixture, leading to several distinct symptoms. Because the hose is part of the emissions system, a failure will almost always trigger a Check Engine Light.
- Rough Idle and Poor Performance: The most common symptom is a rough or unstable idle. A vacuum leak allows unmetered air into the engine, causing the air-fuel ratio to become too lean, which the engine's computer struggles to correct.
- Whistling or Sucking Noises: You may hear a distinct whistling or sucking sound from the engine bay at idle. This is the sound of air being pulled through the crack in the hose.
- Check Engine Light: A vacuum leak will trigger lean codes, most commonly P0171 (System Too Lean Bank 1). This is a clear sign that the engine's computer is detecting too much oxygen in the exhaust. 🎬 Watch this video to see common symptoms of breather failure.
- Increased Oil Consumption: While less common for a simple hose failure, if the PCV system is compromised for too long, increased crankcase pressure can lead to higher oil consumption or even force oil past engine seals.
Is There a Recall?
While there have been significant recalls for the PCV valve heater on some BMW models, these generally apply to older or different engine types (like the N51 and N52) and model years outside the 2012-2016 range for the 528i. The specific crankcase breather hose (part number 11127588417) for the 2012-2016 528i is not part of a major recall, but its failure is a well-documented maintenance issue.
Choosing the Right Aftermarket Replacement
When replacing the breather hose, you have a choice between original BMW parts and aftermarket options. For a part like this, a high-quality aftermarket brand offers a smart balance of cost and reliability.
- OEM (Original Equipment Manufacturer): The genuine BMW part (part number 11127588417) is the benchmark for quality and fitment. However, it is the most expensive option.
- Aftermarket - Tier 1 (CRP/Rein): CRP, which sells under the brand name Rein, is an OEM supplier to BMW for many components. Choosing a Rein hose is often like getting the genuine part without the BMW logo and price tag. They are known for excellent quality and fitment.
- Aftermarket - Tier 2 (Gates): Gates is a globally respected manufacturer of hoses and belts. While perhaps not an OEM supplier for this specific BMW part, their products are known for durability and are a reliable and cost-effective choice.
Pro Tip: Given that the failure is due to plastic becoming brittle, both OEM and quality aftermarket replacements will eventually wear out. The key is using a reputable brand. For the price, a quality aftermarket hose from a brand like CRP/Rein provides the best value without compromising on performance.
Cost of Replacement
| Part Type | Estimated Cost |
|---|---|
| New Aftermarket (CRP, Gates) | $73.09 - $84.05 |
| New OEM (Genuine BMW) | $100 - $150 |
| Shop Labor | $100 - $200 |
Frequently Asked Questions
Is it difficult to replace the 528i crankcase breather hose?
No, this is considered a relatively easy DIY job for most home mechanics. The hose is located on top of the engine and is easily accessible after removing the engine cover. It is held in place by simple clips. The entire job can typically be done in under an hour with basic tools.
🎬 See how to replace the crankcase ventilation valve yourself.What happens if I don't replace a broken breather hose?
Continuing to drive with a broken breather hose is not recommended. The persistent lean air-fuel mixture can cause poor fuel economy and rough running. Over time, increased crankcase pressure could potentially lead to more serious oil leaks from gaskets and seals, resulting in more expensive repairs.
What is the difference between the breather hose and the PCV valve?
The breather hose is simply the tube that transports the gases. The PCV valve (or the entire PCV system, which can be integrated into the valve cover on the N20 engine) is what regulates the flow and pressure of these gases. In this case, the hose is a common failure point that creates a vacuum leak.
Will a new hose fix my P0171 lean code?
If the hose is cracked, then yes, replacing it is very likely to fix a P0171 code. A cracked breather hose is one of the most common causes of a vacuum leak on the N20 engine. After replacing the hose, the code should be cleared. If it returns, further diagnosis will be needed to check for other potential vacuum leaks or fuel system issues.
Helpful Videos
Technical Specifications
OEM Part Numbers: 11127588417
Material: Plastic; Connection: Connects valve cover to turbocharger air inlet pipe.
We Have This Part in Stock
The information in this article is provided for general reference and educational purposes only. Vehicle specifications, procedures, and part compatibility can vary by production date, trim level, and region. Always consult your vehicle's factory service manual and verify part numbers before purchasing or performing repairs. Safety-critical components such as airbags, seat belts, and braking systems should be installed by a qualified professional.
- BMW 528i: