BMW 11317594903 Engine Left Cylinder Head 306-59506 4.4L N63B

( Manufacturer Part Number: 11317594903 ), ( Part Type: Engine Cylinder Head ), ( Donor Year: 2014 ), ( Ipn: 306-59506 ), ( Miles: 143, 488 ), ( Tag: V53258 )

Review BMW 4.4l Engine Left Cylinder Head fits TWIN 550I 650I 750I X5 X6 TURBO 2013–2019

The **BMW N63B44T0 twin-turbocharged inline-six engine** (part number **11317594903**, covering models from **2013 to 2019**, including the **550i, 650i, 750i, X5 sDrive65i, and X6 sDrive65i**) represents a pinnacle of BMW s engineering prowess, blending raw performance with refined efficiency in its **4.4-liter displacement**. This high-output powerplant is a direct evolution of the legendary N63 family, known for its aggressive twin-turbocharged architecture, which delivers an exhilarating **400 445 horsepower** (depending on the variant) and **479 525 lb-ft of torque**, all while maintaining a balance of responsiveness and drivability. The engine s **left cylinder head** a critical component in this layout features an advanced **direct-injection system** paired with **port injection** for optimized fuel delivery, ensuring precise combustion and reduced emissions without sacrificing performance. Its **two turbochargers** (a smaller high-pressure unit and a larger low-pressure unit) work in tandem to spool rapidly, eliminating lag and providing near-instantaneous throttle response, a hallmark of BMW s **Double-VANOS variable valve timing** technology. The **aluminum block** and **forged crankshaft** contribute to durability and high-revving capability, while the **intercooler system** and **high-flow exhaust manifolds** further enhance efficiency and power output. This engine is not just a brute-force performer; it s engineered with **BMW s iDrive-integrated powertrain management**, which dynamically adjusts boost levels, fueling, and ignition timing for optimal performance across a wide RPM range. Whether under the hood of a **550i Gran Coupe** or the **X6 sDrive65i**, this powerplant embodies BMW s commitment to blending German precision with the thrill of a high-performance V8 alternative, all while maintaining the compact, efficient nature of an inline-six. For enthusiasts seeking a balance of power, refinement, and cutting-edge technology, the N63B44T0 remains one of the most sought-after and capable engines in BMW s lineup.

### **Pros and Cons of Buying a BMW N63B40 Twin-Turbo V8 (2013 2019) with a Left Cylinder Head Issue**

#### **Overview**

The BMW N63B40 engine, introduced in 2013, is a twin-turbocharged V8 powerplant found in models like the **550i, 650i, 750i, X5 (x.drive40i), and X6 (x.drive40i)**. While it delivers impressive performance (400 445 hp, depending on the model), it has gained a reputation for reliability concerns, particularly with **left cylinder head issues** (exhaust manifold cracking, head gasket leaks, or turbocharger failures). Below is a detailed breakdown of its strengths and weaknesses.

---

### **Pros**

1. **Exceptional Performance**

- The N63 produces strong power (400 445 hp) and torque (429 450 lb-ft), making it one of the most capable BMW V8 engines of its era.

- Twin-turbo setup ensures linear power delivery, improving throttle response compared to single-turbo V8s.

- High-revving nature (up to 6,500 RPM) provides a satisfying driving experience, especially in manual or ZF 8-speed automatic models.

2. **Luxury and Comfort**

- BMW s **iDrive infotainment** (though sometimes glitchy) and premium interior materials make for a refined driving experience.

- Available **x.drive40i AWD** provides excellent traction in adverse conditions.

- Comfortable ride tuning (especially in X5/X6) makes long drives enjoyable.

3. **Resale Value (Compared to Competitors)**

- While not as high as a well-maintained M5 or 550i, it holds value better than many luxury SUVs or sedans in its class.

- The **750i** retains prestige, though it s less common than the 550i/X5.

4. **Aftermarket Support**

- Strong aftermarket community for tuning (e.g., **MHD, BMS, or custom turbo upgrades**).

- Performance parts (e.g., **cold air intakes, exhausts, or ECU tunes**) can enhance power and drivability.

5. **Durability (If Properly Maintained)**

- The **block and crankshaft** are robust, and with regular maintenance, the engine can last **150,000 miles**.

- **Oil consumption** is a known issue, but some owners report it stabilizes after 50,000 miles.

---

### **Cons**

1. **Left Cylinder Head Reliability Issues (Most Critical Problem)**

- **Turbo lag and thermal stress** (exhaust side runs hotter).

- **Oil leaks** from the **left turbocharger** (common failure point).

- **Exhaust manifold cracks** (especially near the turbo).

- **Blue smoke** from the exhaust (burning oil).

- **White smoke** (head gasket failure).

- **Misfires, rough idle, or check engine lights** (P0300-P0308 codes).

- **Oil leaks** around the turbo or head.

- **Repair costs** can range from **$2,500 $5,000 ** depending on labor and parts (some require **full head replacement**).

2. **Oil Consumption (Common but Manageable)**

- Many N63 engines **burn oil**, especially early models (pre-2015).

- **Symptoms:** Blue smoke from exhaust, low oil levels despite frequent top-ups.

- **Oil catch can** (reduces oil loss but doesn t eliminate it).

- **ECU tune** (can help reduce consumption).

- **Regular oil changes** (BMW recommends **5,000-mile intervals**).

- Some owners report oil burn stabilizes after 50,000 70,000 miles.

3. **Turbocharger Failures**

- The **left turbocharger** is more prone to failure due to higher exhaust temperatures.

- Symptoms: **Whining noise, loss of power, or check engine lights (P0010, P0011, P0012)**.

- Replacement cost: **$1,500 $3,000 per turbo** (often requires labor-intensive removal).

4. **Transmission Issues (ZF 8HP in X5/X6)**

- Some **ZF 8-speed automatics** in X5/X6 models have reported **rough shifting or failure** after high mileage.

- **Costly repairs** ( $3,000 $5,000 for a rebuild).

5. **Electrical and Infotainment Problems**

- **iDrive glitches** (freezing, unresponsive touchscreen).

- **Sensor failures** (mass airflow sensor, throttle position sensor).

- **Battery drain issues** (common in older BMWs).

6. **Maintenance Costs**

- **High repair bills** compared to naturally aspirated engines.

- **Specialized labor** required for turbo and head work.

- **Oil changes** should be done with **BMW-approved synthetic oil** (e.g., **LL-01 or LL-04**).

7. **Depreciation**

- While not as bad as some luxury brands, BMWs lose value over time.

- The **N63 s reliability issues** may deter some buyers, affecting resale.

---

### **Conclusion & Recommendation**

#### **Who Should Buy?**

**Enthusiasts who prioritize performance over longevity** and are willing to **budget for potential repairs**.

**Owners who plan to keep the car for 50,000 100,000 miles with diligent maintenance**.

**Those who enjoy tuning and modifying** (the N63 responds well to upgrades).

**Buyers who can afford the risk** of left cylinder head or turbo failures.

#### **Who Should Avoid?**

**Budget-conscious buyers** repair costs can be prohibitive.

**Those who want a "set-and-forget" luxury car** without major maintenance concerns.

**People who dislike dealing with turbocharged engine quirks** (oil burn, turbo lag).

**Buyers who prioritize long-term reliability over short-term power**.

#### **Final Recommendations**

- **Left cylinder head condition** (look for cracks, warping, or oil leaks).

- **Turbocharger health** (listen for whining, check for leaks).

- **Oil consumption history** (ask for maintenance records).

- **Transmission fluid condition** (if automatic).

2. **Budget for Potential Repairs**

- **Left cylinder head replacement** ( $2,500 $5,000).

- **Turbocharger replacement** ( $1,500 $3,000 per turbo).

- **Head gasket replacement** ( $1,500 $2,500).

- **Oil catch can installation** ( $500 $1,000).

3. **Consider a Lower-Mileage Example (Under 80,000 Miles)**

- Earlier models (2013 2014) have **higher oil burn rates**, while **2016 models** improved slightly.

- **X5/X6 models** are more practical but may have **transmission concerns**.

4. **Alternative Options if N63 is Too Risky**

- **BMw N55 (330i/335i)** More reliable, but less power.

- **BMw N63B44 (2018 550i/750i)** Slightly improved, but still has head/turbo issues.

- **Audi V8 (e.g., 2016 Q7 3.0T)** More reliable turbo V8 alternative.

- **Mercedes-AMG M136 (E63 S63)** Strong performance with better turbo reliability.

5. **If Buying, Prepare for Maintenance**

- **Use high-quality oil** (BMW LL-04 or Mobil 1 ESP).

- **Monitor oil levels** and top up frequently if burning oil.

- **Replace spark plugs, coils, and sensors** as needed.

- **Consider an oil catch can** to reduce oil loss.

---

### **Final Verdict**

The **N63B40 is a fantastic engine for those who love power and don t mind the trade-offs**. However, the **left cylinder head and turbocharger issues make it a high-risk purchase unless thoroughly inspected and maintained**.

Details:

There may be normal signs of wear and tear present such as scratches, scuffs, dirt, etc. Emissions standards, side of road vehicles drive on, etc. Weather patterns cold vs. Initial testing consists of starting the vehicle, running code scans, road if safe to do so, and completing an extensive inspection checklist. After items are removed and cleaned they inspected one final time before posting.

On return this item. And cultural preferences income levels, family sizes, typical modes of transportation, etc.: Item has been fully inspected and tested found to be in good working order. Left-Hand Drive Vehicles.

We subscribe to fitment software and include all relevant useful information in our listings whenever possible. The more actions option. SHIPPING DEALS: Review our shipping details before you purchase. The pictures are the ACTUAL PICTURES OF THE ITEM FOR SALE.

Made for USA Vehicles: All vehicles and parts are manufactured to be sold the market.

part #: 11317594903 prices

• $350.00-$419.99

specifications cylinderheapar:

• for models: 550i, 650i, 750i, X5, X6, Turbo, Twin
• for makes: Bmw
• for years: 2013-2019
• mpn: 11317594903
• part type: Engine Cylinder Head
• donor year: 2014
• ipn: 306-59506
• miles: 143, 488
• tag: V53258

offer cylinderheapar:

• sold: 0
• quantity: 1
• started: April 21, 2026
• availability: In Stock
• options: Ship-to-home

seller cylinderheapar:

• # reviews: 30269
• rating: 99.9%
• city: Oroville, California

returns cylinderheapar:

• policy: Returns Accepted
• time: 60 Days
• paid by: Seller

shipping cylinderheapar:

• transit: 3-7 Days
• cost: $0.00
• service: Standard
• type: Fixed
• class: Standard

general cylinderheapar:

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

payments cylinderheapar:

• wallet: Apple-pay
• credit card: Visa
• other

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