MERCEDES A6420100721 Bluetec Engine Left Cylinder Head Benz OM642 Camshaft

( Manufacturer Part Number: A6420100721 ), ( Part Type: Engine Cylinder Head Camshaft ), ( Placement: Left ), ( Manufacturer Warranty: 3 Months ), ( Items Included: Head Cover Bolts ), ( Country Of Origin: Germany )

Review MERCEDES benz Bluetec Engine Left Cylinder Head Camshaft Oem fits W164 ML350 2010–2011

The **Mercedes-Benz A6420100721 (10-11 W140 ML350 OM642 BlueTec) Left Cylinder Head Camshaft** is a precision-engineered component designed exclusively for the **W140 generation Mercedes-Benz M-Class (ML350) models produced between 2005 and 2011**, featuring the **OM642 diesel engine** with **BlueTec emissions compliance**. This high-performance camshaft is a critical part of the engine s **intake and exhaust valve timing system**, directly influencing power delivery, fuel efficiency, and overall engine responsiveness. Crafted from **high-grade alloy steel**, it is machined to exacting tolerances to ensure seamless operation within the **left cylinder head**, where it governs the opening and closing of the intake valves, optimizing airflow for combustion. The **BlueTec-compliant OM642** a **3.5-liter V6 turbocharged diesel engine** relies on this camshaft to maintain its reputation for **torque-rich performance and reliability**, particularly in applications requiring **durable, high-mileage use**. Whether replacing a worn or damaged camshaft or upgrading for enhanced performance, this part is a **direct-fit OEM replacement**, ensuring compatibility with the original engine architecture while adhering to **Mercedes-Benz s stringent quality standards**. Its precise **gear-driven timing mechanism** synchronizes with the **crankshaft and rocker arms**, delivering the correct valve lift and duration for peak engine efficiency, making it an essential component for maintaining the **ML350 s legendary driving dynamics** while meeting modern emissions regulations. Proper installation requires **specialized tools and expertise**, as misalignment can lead to catastrophic engine damage, underscoring the importance of sourcing this part from a trusted supplier with **authentic Mercedes-Benz parts certification**.

### Pros and Cons of Buying a Mercedes-Benz A6 (W164) ML350 (OM642 Bluetec) from 2010-2011 with the Left Cylinder Head Camshaft Issue

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#### **Pros**

1. **Reliability of the OM642 Engine (When Well-Maintained)**

The OM642 is a robust diesel engine known for its durability, especially when properly serviced. Many owners report long-term reliability if the engine is kept on a strict maintenance schedule, including regular oil changes, fuel system cleaning, and timely repairs for wear-related issues.

2. **Strong Performance for a Diesel**

The 3.5L OM642 produces around 231-265 horsepower (depending on the model year and market) and offers strong torque, making it well-suited for highway driving and towing. The V6 configuration provides a good balance of power and smoothness.

3. **Bluetec Emissions Compliance**

The Bluetec designation indicates that the engine meets Euro 5 emissions standards, which means it is equipped with a diesel particulate filter (DPF) and selective catalytic reduction (SCR) system. While these add complexity, they also ensure the vehicle complies with modern emissions regulations, which can be important for resale or long-term use in regions with strict environmental laws.

4. **Comfortable and Spacious Interior**

The W164 A-Class (or A6, depending on market) is known for its high-quality interior materials, comfortable seating, and ample legroom. The cabin feels premium, which is a hallmark of Mercedes-Benz.

5. **Good Resale Value (Compared to Some Competitors)**

Mercedes-Benz vehicles, especially well-maintained ones, retain their value relatively well. The OM642 diesel models, in particular, have a dedicated following, which can help with resale if the vehicle is kept in good condition.

6. **Availability of Parts and Mechanics**

As a relatively common model (especially in Europe and some parts of North America), parts for the OM642 are widely available. There are also many mechanics familiar with Mercedes diesel engines, which can make repairs and maintenance more straightforward.

7. **Potential for Modifications**

The OM642 is a popular platform for tuning, with aftermarket support for upgrades like turbocharger swaps, fuel system enhancements, and exhaust modifications. This can be appealing to enthusiasts looking to increase power or improve performance.

8. **Safety Features**

The W164 A6 comes equipped with modern safety features for its time, including stability control, multiple airbags, and advanced braking systems. These features contribute to a safer driving experience.

---

#### **Cons**

1. **Left Cylinder Head Camshaft Issue (Specific to This Engine)**

The left cylinder head camshaft in the OM642 is notorious for wearing out prematurely, often around 100,000 to 150,000 miles (160,000 to 240,000 km). This issue can lead to misfires, rough idling, loss of power, and eventually catastrophic engine failure if not addressed. The repair involves replacing the camshaft, which can be costly (often $1,500 $3,000 or more, depending on labor rates and parts). Some owners have reported that the right cylinder head camshaft can also wear out over time, though less frequently.

2. **DPF and SCR System Reliability**

The Bluetec emissions system requires regular maintenance, including DPF regeneration (which can be triggered by short trips or low-speed driving) and SCR fluid top-ups. Clogged DPFs can lead to reduced performance or even engine shutdowns if not addressed promptly. The SCR system also adds complexity and cost to ownership, as SCR fluid (AdBlue) must be purchased and added periodically.

3. **High Maintenance Costs**

Mercedes-Benz vehicles, especially diesels, are known for their high maintenance and repair costs. While the OM642 is durable, routine maintenance (oil changes, fuel filters, injectors, turbocharger servicing) can add up. Additionally, labor costs for Mercedes dealerships or specialized shops can be steep.

4. **Fuel Economy Trade-offs**

While the OM642 is efficient for a diesel, the emissions system and other modern features can slightly reduce fuel economy compared to older diesel models without DPF/SCR. Additionally, AdBlue consumption adds to the overall cost of ownership.

5. **Common Wear Items**

- **Injectors**: Commonly fail or clog, requiring replacement every 100,000 150,000 miles.

- **Turbocharger**: The wastegate turbochargers on the OM642 can wear out, leading to loss of boost and performance.

- **Fuel Pump**: The high-pressure fuel pump can fail, causing rough running or stalling.

- **Water Pump and Timing Belt**: These are critical components that must be replaced at recommended intervals (typically every 60,000 100,000 miles). Neglecting them can lead to engine damage.

6. **DPF Regeneration Hassles**

The DPF requires periodic regeneration to burn off soot. This can happen automatically during highway driving, but if the vehicle is driven mostly in stop-and-go traffic or short trips, the DPF can clog prematurely. Manual regeneration (driving at high speeds) may be required, which can be inconvenient.

7. **Resale Value Decline**

While Mercedes-Benz retains value, diesel models with emissions systems and known issues (like the camshaft) may depreciate faster than their gasoline counterparts. Buyers may be wary of purchasing a diesel with a history of camshaft problems.

8. **Noise and Vibration**

Some owners report increased noise and vibration from the OM642, particularly as components wear. The engine can also be louder than expected, especially when cold.

9. **Limited Long-Term Data**

The W164 A6 was produced from 2004 to 2011, and the OM642 was used in several generations of Mercedes diesels. While the engine is proven, long-term data (beyond 200,000 miles) on the specific left camshaft issue is limited. Some owners report that the right camshaft can also fail later in the engine s life.

10. **Dealer vs. Independent Shop Repairs**

Mercedes dealerships often charge premium prices for repairs, and parts can be expensive. Independent shops may offer better pricing but could lack the expertise or warranty coverage for Mercedes-specific issues.

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#### **Ending Conclusion**

Buying a 2010-2011 Mercedes-Benz A6 (W164) ML350 with the OM642 Bluetec engine can be a good investment if you are prepared for its quirks and willing to commit to regular maintenance. The engine is powerful and reliable when well-cared-for, but the left cylinder head camshaft issue is a significant drawback that cannot be ignored. If the camshaft has already failed or is showing signs of wear (e.g., misfires, rough idle, or check engine lights), the repair cost can be prohibitive. Additionally, the emissions system adds complexity and ongoing costs (AdBlue, DPF regeneration).

For a diesel enthusiast or someone who plans to keep the vehicle for a long time and budget for potential repairs, this car can be a rewarding purchase. However, if you are looking for a low-maintenance, hassle-free vehicle or are not comfortable with the risks associated with the camshaft issue, it may be better to consider alternatives, such as a gasoline-powered Mercedes or a different diesel model with a proven track record.

---

#### **Recommendation**

- **Verify the camshaft condition**: Have a trusted mechanic inspect the left cylinder head camshaft thoroughly. If it s already worn or failing, factor in the repair cost (or negotiate the purchase price accordingly).

- **Check maintenance history**: Ensure the vehicle has a complete service record, including oil changes, injector cleanings, and timely replacements of wear items like the timing belt, water pump, and turbochargers.

- **Budget for future repairs**: Allocate funds for potential injector replacements, turbocharger servicing, and DPF/SCR maintenance. Consider setting aside $1,000 $2,000 annually for unexpected repairs.

- **Drive it appropriately**: Avoid short trips and frequent stop-and-go driving to minimize DPF clogging and extend the life of the engine components.

- **Consider independent mechanics**: While dealerships are convenient, independent shops with Mercedes experience may offer better pricing for repairs.

- **Look for alternatives**: Consider a gasoline-powered Mercedes (e.g., A6 M276 engine) or a different diesel model with a better reputation for reliability (e.g., some Volkswagen TDI or BMW N57 engines, though these also have their own issues).

- **Test drive and inspect thoroughly**: Before purchasing, take the car for a long test drive to listen for unusual noises (e.g., tapping from the camshaft) and check for warning lights on the dashboard.

- **Get a pre-purchase inspection**: Hire a mechanic to perform a detailed inspection, focusing on the camshaft, injectors, turbocharger, and emissions

Details:

EXTERIOR COLOR: ARCTIC WHITE 650. Enter the yard by permission only. TRANSMISSION: AT AUTO 722.902. Please remember.

Examples of these non-warranty parts include switches, sensors, cables, coils, wires, injectors, electronics, belts including timing belt/chain, hoses, water pumps, brackets, intake/exhaust manifolds, oil pans, and turbos/superchargers. Regular mail USPS, FedEx, UPS. ENGINE: 3.0L DIESEL 642.820 AWD. For large items engines, doors, transmissions, body parts, etc.

Warranty does NOT cover labor, diagnostic, towing, or rental car costs. Company name and address;. Contact phone number of the receiving person;. Trucks often run late, and they can come without a call at any time.

REMOVED FROM: 2011 Mercedes ML350 BLUETEC W164. The color in the photos may be different from real one. E-mail address to send a confirmation. If you don't want any surprises - keep in touch with a transporter yourself.

Shipping Info.

part #: a6420100721 prices

• $66.00-$623.73

specifications cylinderheapar:

• for models: W164, Ml350
• for makes: Mercedes
• for years: 2010-2011
• mpn: A6420100721
• part type: Engine Cylinder Head Camshaft
• placement: Left
• manufacturer warranty: 3 Months
• items included: Head Cover Bolts
• country of origin: Germany

returns cylinderheapar:

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

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• city: New Brunswick, New Jersey
• rating: 99.8%
• # reviews: 35677

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general cylinderheapar:

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

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• started: June 7, 2026
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• options: Ship-to-home
• quantity: 1
• best offers: True
• availability: In Stock

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