A Guide to the Engine Crankcase Breather Hose on Your 2007-2016 BMW 328i
Understanding this critical emissions part can save you from rough idling, oil leaks, and check engine lights.
- Identify your engine: 2007-2013 models use the N52 engine, while 2012-2016 models use the N20. The hoses are different.
- A whistling noise at idle is a tell-tale sign of a cracked breather hose.
- For the N52 engine (2007-2013), check if the PCV heater recall (22V-119) has been performed.
- Choose a quality OEM-supplier brand like CRP/Rein for this plastic part to ensure durability and proper fit.
Understanding Your 328i's Breather Hose: E90 vs. F30
The 2007-2016 BMW 328i spans two different vehicle generations, and they use completely different engines and breather hoses. It is critical to identify your specific model to get the right part.
- 2007-2013 (E90, E91, E92, E93 chassis): These models use the 6-cylinder N52 engine. The primary breather hose is a long, complex plastic tube that runs from the valve cover at the back of the engine to the oil separator (PCV valve) which is buried under the intake manifold. These become extremely brittle with age and often break during other repairs.
- 2012-2016 (F30 chassis): These models use the 4-cylinder turbocharged N20 or N26 engine. The breather hose is a shorter, simpler tube that connects from the valve cover directly to the main air intake pipe. While easier to access, it is still a common failure point.
Symptoms of a Failing Breather Hose
A cracked or broken crankcase breather hose creates a vacuum leak. This allows unmetered air into the engine, disrupting the carefully balanced air-fuel mixture. Here’s what you might notice:
- Rough Idle: The engine may stumble or idle erratically.
- Whistling or Sucking Noises: A high-pitched whistle from the engine bay at idle is a classic sign of a vacuum leak from a broken hose.
- Check Engine Light: You will likely get a "Service Engine Soon" light with lean codes (like P0171 and P0174) or misfire codes.
- Increased Oil Consumption: A malfunctioning PCV system can cause the engine to burn more oil.
- Visible Cracks: The plastic becomes brittle from heat and age and will often have obvious cracks or may even be broken in two.
Fire Risk Recall for N52 Engines (2007-2013)
There is an important safety recall (NHTSA 22V-119) for the PCV valve heater on 2007-2013 328i models with the N52 engine. This heater is part of the breather hose assembly and can short circuit, creating a fire risk even when the car is parked. You can check with a BMW dealer or on the NHTSA website to see if your vehicle has had the recall performed. The fix involves replacing the hose connector and installing a new fused wiring harness.
Choosing the Right Aftermarket Part
When it comes to plastic and rubber engine components on a BMW, quality matters. Using a low-quality part can lead to a repeat failure in a short time. For this specific hose, you have good aftermarket options.
- OEM-Supplier (CRP/Rein): Brands like CRP (often sold under the Rein name) are frequently the Original Equipment Manufacturer (OEM) for BMW. This means they made the original part for BMW. Choosing a Rein hose is like getting the dealer part without the dealer price tag. They are known for correct fitment and durable materials.
- Quality Aftermarket (Gates): Gates is a well-known and respected aftermarket brand that produces a wide range of automotive hoses. Their products are a reliable alternative to the OEM part and often provide good value.
Pro Tip: Given the high heat and vibration in the engine bay, spending a little more on a quality OEM-supplier brand like CRP/Rein for this part is a wise investment to ensure longevity and prevent future vacuum leaks.
Cost of Replacing the Engine Crankcase Breather Hose
| Part/Service | Estimated Cost |
|---|---|
| New OEM Part | $65 - $80 |
| New Aftermarket Part (CRP, Gates) | $53.24 - $84.05 |
| Shop Labor | $150 - $400 |
Note: Labor costs vary significantly based on engine type. The N52 hose (2007-2013) is much more labor-intensive to replace than the N20 hose (2012-2016). Some shops may recommend removing the intake manifold for the N52, which increases labor time.
Frequently Asked Questions
Is this the same as the PCV valve?
No, but they are related. On the N52 engine (2007-2013), this hose connects to the PCV valve (oil separator). On the N20 engine (2012-2016), the PCV valve is integrated into the valve cover, and this hose vents the gases from it. A failure of this hose is often misdiagnosed as a bad PCV valve.
What happens if I don't replace a broken breather hose?
You will continue to have a rough running engine, poor fuel economy, and a persistent check engine light. Over time, the incorrect air-fuel mixture can lead to fouled spark plugs and damage to the catalytic converter. The unmanaged crankcase pressure can also stress other engine seals, potentially causing new oil leaks.
How do I know which hose to buy for my 328i?
The easiest way is to identify your engine. If you have a 2007-2013 model, you almost certainly have the 6-cylinder N52 engine. If you have a 2012-2016 model, you have the 4-cylinder N20/N26 engine. The parts are not interchangeable. The OEM part number for the N52 hose is typically 11157559528, and for the N20 hose, it is 11127588417. Always verify fitment with your vehicle's VIN.
Can I replace this hose myself?
For the F30 (2012-2016), it is a relatively simple DIY job requiring minimal tools. For the E90 (2007-2013), it is much more difficult due to the hose's location behind the engine and under the intake manifold. The plastic connectors become very brittle and often break upon removal, requiring patience and care. Many owners break the old part off intentionally and use tools to carefully remove the broken pieces from the connection points.
Helpful Videos
Technical Specifications
OEM Part Numbers: 11157559528 (for N52 engine, 2007-2013) 11127588417 (for N20/N26 engine, 2012-2016)
The hose is made of molded plastic and features push-in connectors at both ends. Depending on the engine, it may include an integrated wiring harness for a PCV heater (N52) or a sensor (N20). The plastic becomes brittle over time due to engine heat and oil vapor exposure.
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.
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