BMW F7521378 Cylinder Head Mini 2.0L

( Manufacturer Part Number: F7521378 ), ( Part Type: Cylinder Head ), ( Bmw Part Name: Cylinder Head With Valve Gear ), ( Full Part Number: 11122906665 ), ( Other Numbers: F7521378, 11128482777, 8482777, 11318618192, 8618192, 8611287, 11318611287, 2462160, 11312462160, 11318618193 ), ( Other Numbers 2: 8618193, 8611288, 11318611288, 2462161, 11312462161 ), ( Other Names: B48 Head B46 Head, Camshafts, Valvesprings, Vanos ), ( Interchangeable Part Numbers: 2906649, 1557369, 2906268, 8631741 ), ( Interchangeable Full Part Numbers: 11122906649, 11121557369, 11122906268, 11128631741 ), ( Bmw Chassis: F60, F57, F56, F55, F54, F48, F39 ), ( Manufacturer Part Number Revisions: F7521378-01, F7521378-02, F7521378-03, F7521378-04, F7521378-05, F7521378-06, F7521378-07, F7521378-08, F7521378-09, F7521378-10 )

Review BMW Oem Cylinder Head 2.0l Mini fits B46 X1 X2 F48 F57 F39 F54 F55 2016–2018

The **BMW B46 2.0L TwinPower Turbo inline-4 cylinder head (F7521378)** is a meticulously engineered component designed for the high-performance **N55/N57** engine family, which powers a range of BMW models including the **F48 (1 Series), F57 (2 Series Gran Tourer), F39 (X1), F54 (X2), F55 (X3), and F56 (X4)** produced between **2016 and 2018**. This cylinder head is a critical part of the **B46** engine architecture, featuring a **16-valve, dual overhead camshaft (DOHC) design** with **variable valve timing (Valvetronic)** on the intake side and **fast-acting variable valve lift (VANOS)** on both intake and exhaust, ensuring optimal airflow and efficiency across the RPM range. Crafted from high-strength aluminum alloy, the head is precision-machined to accommodate the **direct-injection fuel system**, **turbocharged induction**, and **high-pressure fuel rail** that define the N55/N57 s performance-oriented nature. The **integrated intake manifold** and **exhaust manifold ports** are engineered for minimal restriction, allowing for aggressive turbocharging while maintaining reliability. This cylinder head is compatible with both **N55 (2.0L) and N57 (2.0L) variants**, making it a versatile upgrade or replacement option for enthusiasts seeking improved performance, better cooling efficiency, or restoration purposes. Whether used in a **stock or modified application**, this head is built to withstand the demands of modern turbocharged engines while delivering the precise airflow control necessary for BMW s signature driving dynamics. For those looking to maintain or enhance their vehicle s performance, this **OEM-spec cylinder head** ensures a seamless fit and reliable operation, embodying BMW s commitment to precision engineering.

### **Pros and Cons of Buying a BMW B46 2.0L I4 Cylinder Head (F75, F48, F57, F39, F54, F55 Models, 2016 2018)**

The **BMW B46 2.0L inline-4 engine** (used in the **F75 X5, F48 Z4, F57 X3, F39 4 Series, F54 X1, and F55 X2**) is a refined turbocharged unit with strengths in efficiency and drivability, but it also has notable weaknesses particularly in reliability and cost of ownership. Below is a detailed breakdown of its advantages and drawbacks.

---

### **Pros of the B46 Engine**

1. **Fuel Efficiency and Low Emissions**

- The B46 is BMW s most efficient naturally aspirated or turbocharged engine in its class, achieving ** 20 25 MPG (combined)** in the X1/X2 and ** 18 22 MPG** in the X5/X3, depending on transmission and driving style.

- It meets **Euro 6d-TEMP emissions standards**, making it compliant with stricter regulations without excessive aftermarket modifications.

- The **valvetronic variable intake system** and **direct injection** improve throttle response and efficiency compared to older BMW inline-4s (e.g., N54).

2. **Smooth and Responsive Turbocharging**

- The **single-scroll turbo** (with a wastegate) provides **linear power delivery**, avoiding the turbo lag common in earlier BMW turbos (e.g., N55).

- Peak power ( 258 hp in the X1/X2, 306 hp in the X5/X3) is delivered **early**, making it feel quick in daily driving.

- The **variable geometry turbo (VGT)** in some variants (e.g., F55 X2) further refines low-end torque.

3. **Lightweight and Compact Design**

- The **aluminum block and head** keep weight down, improving fuel economy and handling (notable in the F48 Z4 and F54 X1).

- The **narrow 2.0L displacement** allows for better packaging in smaller BMWs (X1/X2) without sacrificing performance.

4. **Reliability Improvements Over Older BMW Inline-4s**

- **No carbon buildup issues** (due to BMW s shift to **direct injection only**).

- **Improved oil control rings** (reducing oil consumption compared to the N55).

- **A more robust turbocharger** (though still not bulletproof).

- The **fuel pump and injectors** are more reliable than those in the N54.

5. **Good for Daily Driving**

- The B46 is **quiet, smooth, and comfortable** at highway speeds, making it ideal for commuting.

- **Low-end torque** (thanks to the turbo) means it feels peppy even at low RPMs.

- **No major known issues** that make it impractical for daily use (unlike the N54 s oil leaks or the N20 s timing chain problems).

6. **Aftermarket Support**

- The B46 has a **growing aftermarket**, with tuners like **BMW Tuning, JB4, and APR** offering **ECU flashes and turbo upgrades**.

- **Stage 1 tunes** can reliably add **30 50 hp** without major modifications.

- **Direct port injection (DPI) kits** (e.g., **BMS or JB4**) can help with longevity if running high power.

7. **Lower Cost Than V8 or V6 Alternatives**

- Compared to the **N63 V8 (F10/F15/F16)** or **N55 N20 V6 (F30)**, the B46 is **cheaper to buy, insure, and maintain**.

- **Parts are widely available**, and labor costs are lower than for high-performance BMWs.

---

### **Cons of the B46 Engine**

1. **Turbocharger Reliability Issues**

- **Oil starvation** (if oil pressure drops, e.g., from a failing oil pump or clogged oil filter).

- **Boost leaks** (common in older models due to **O-rings and gaskets drying out**).

- **Turbo bearing wear** (if the engine is neglected or over-revved).

- **Whining noise** (bearing wear).

- **Loss of power** (exhaust restriction).

- **Blue smoke** (oil burning due to turbo failure).

- **Replacement cost**: **$1,500 $3,000** (including labor and new turbo).

2. **Oil Consumption (Mild but Present)**

- Some B46 engines **burn oil**, especially in **high-mileage examples (100K miles)**.

- **Blue smoke from exhaust** (especially after cold starts).

- **Low oil levels** requiring frequent top-ups.

- **Worn piston rings or valve seals**.

- **Turbo oil leaks** (if the turbo is failing, it can cause oil to burn).

- **Fix**: **Ring job ( $1,500 $2,500)** or **valve seal replacement ( $800 $1,500)**.

3. **Carbon Buildup (Less Severe Than N54, But Still Possible)**

- Unlike the N54, the B46 **does not have port injection**, so **carbon buildup is less aggressive**.

- **Rough idle or misfires**.

- **Reduced throttle response**.

- **Solution**: **Carbon cleaning ( $300 $600)** every **50,000 70,000 miles**.

4. **Water Pump and Thermostat Failures**

- **Overheating**.

- **Coolant leaks** (common in the **F54 X1 and F55 X2**).

- **Replacement cost**: **$500 $1,200** (labor parts).

- **Coolant leaks under the hood**.

- **Temperature gauge fluctuating**.

- **Coolant reservoir losing fluid**.

5. **Suspension and Electrical Issues (Model-Specific)**

- **Suspension bushings wear out quickly** (especially in off-road models).

- **Electrical gremlins** (e.g., **faulty sensors, infotainment glitches**).

- **Soft top leaks** (common in older models).

- **Rust issues** (if driven in wet climates).

- **Rear subframe rust** (if not maintained).

- **Electrical issues with the iDrive system**.

6. **Transmission Reliability (ZF 8HP in X5/X3, Getrag in X1/X2)**

- **Band wear** can cause **delayed shifts or slipping**.

- **Solenoid failures** may require **$1,500 $2,500** in repairs.

- The **Getrag 6HP (F54/F55)** is **more robust** but can still develop **clutch or torque converter issues**.

7. **Higher Maintenance Costs Than a Naturally Aspirated Engine**

- **Turbo inspections** every **50,000 70,000 miles**.

- **Oil changes with synthetic oil** (BMW recommends **5W-40 or 0W-40**).

- **Carbon cleaning** (if running high miles).

- **Total annual maintenance cost**: **$800 $1,500** (higher than a **3.0L diesel or N55 V6**).

8. **Resale Value (Not Great for a BMW)**

- The **B46 is not a high-performance engine**, so **resale values decline faster** than for **N63 V8 or S55 models**.

- **X1/X2

Details:

Pay close attention to the 'BUILD DATES' column - if it doesn't say 'All,' confirm that your vehicles build date falls within specified range. Please review the high-resolution photos carefully. Straight with no cracks or damage. Only includes what is photographed.

This cylinder head has been inspected and tested by a certified technician. Removed from an X1 spec B46 with 56k miles. BMW X1: SUV - F48: Year: model: Eng: Type: Build Dates: 2016 18 X1 xDrive28i B46 HT30 Up to 01/2017, sDrive28i HU73 11/2015 HT33 01/2017. Missing fuel pump tower.

BMW X2: SUV - F39: Year: model: Eng: Type: Build Dates: 2018 X2 xDrive28i B46 YJ53 Up to 01/2017. See warranty details below for coverage after installation. To ensure compatibility, locate your vehicle in the tables below. Will fit virtually all pre-LCI F48 X1s and X2s, along with B46 powered Minis.

The installation procedure is not DIY-friendly. Item Details: Good. Known issues inherent to this cylinder head may not be covered. Cams are in fair condition, journals OK but not excellent.

part #: f7521378 price

• $550.00

specifications cylinderheapar:

• for models: B46, X1, X2, F48, F57, F39, F54, F55
• for makes: Bmw
• for years: 2016-2018
• mpn: F7521378
• part type: Cylinder Head
• bmw part name: Cylinder Head With Valve Gear
• full part number: 11122906665
• other numbers: F7521378, 11128482777, 8482777, 11318618192, 8618192, 8611287, 11318611287, 2462160, 11312462160, 11318618193
• other numbers 2: 8618193, 8611288, 11318611288, 2462161, 11312462161
• other names: B48 Head B46 Head, Camshafts, Valvesprings, Vanos
• interchangeable part numbers: 2906649, 1557369, 2906268, 8631741
• interchangeable full part numbers: 11122906649, 11121557369, 11122906268, 11128631741
• bmw chassis: F60, F57, F56, F55, F54, F48, F39
• manufacturer part number revisions: F7521378-01, F7521378-02, F7521378-03, F7521378-04, F7521378-05, F7521378-06, F7521378-07, F7521378-08, F7521378-09, F7521378-10

offer cylinderheapar:

• options: Ship-to-home
• sold: 0
• quantity: 1
• availability: In Stock
• started: February 24, 2026
• best offers: True

general cylinderheapar:

• condition: Used
• Car Truck Parts Accessories > Engines Engine Parts > Cylinder Heads

seller cylinderheapar:

• rating: 99.6%
• city: Springville, Utah
• # reviews: 1004

payments cylinderheapar:

• wallet: Paypal
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returns cylinderheapar:

• time: 30 Days
• paid by: Seller
• policy: Returns Accepted

shipping cylinderheapar:

• transit: 3-8 Days
• class: Standard
• type: Fixed
• cost: $59.95
• service: Standard

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