The Best Years For Bmw 335d And Some To Avoid

The BMW 335d, a diesel-powered variant of the popular 3 Series, offers a compelling blend of performance and fuel economy that appeals to many drivers. However, not all model years are created equal. This guide delves into the best years for the 335d, highlighting those to seek out and some to potentially avoid, ensuring you make an informed purchase.

BMW 335d Model Year Comparison

Detailed Explanations

Engine Performance: The E90/E91 335d (2009-2011) features a twin-turbocharged 3.0-liter inline-6 diesel engine producing 265 horsepower and 425 lb-ft of torque. This provides strong, immediate power across the rev range. The F30 335d (2014-2018) utilizes a single-turbocharged 3.0-liter inline-6 diesel, slightly detuned to 255 horsepower and 413 lb-ft of torque, focusing more on efficiency. While the F30's power delivery is still impressive, the E90/E91 offers a more raw and aggressive feel.

Common Issues (E90/E91 335d):

• Carbon Buildup: Diesel engines, particularly those with direct injection like the 335d, are susceptible to carbon buildup on the intake valves. This can reduce airflow, leading to decreased performance, poor fuel economy, and rough idling. Regular intake valve cleaning (walnut blasting) is often required to mitigate this issue.

• Swirl Flap Issues: The intake manifold contains swirl flaps designed to improve low-end torque and fuel economy. These flaps can break and be ingested into the engine, causing significant damage. Many owners preemptively remove or replace the swirl flaps with aftermarket alternatives.

• Emissions System Failures: The E90/E91 335d uses complex emissions control systems, including a diesel particulate filter (DPF) and diesel oxidation catalyst (DOC). These systems can fail over time, leading to costly repairs. Issues can range from clogged DPFs requiring regeneration or replacement to faulty sensors and control modules.

Common Issues (F30 335d):

• EGR Cooler Failures: The exhaust gas recirculation (EGR) cooler is prone to cracking and leaking coolant. This can lead to overheating, engine damage, and costly repairs. Upgraded EGR coolers are available as aftermarket solutions.

• Timing Chain Issues (Later Models): Some F30 335d models, particularly those from later production years (2016-2018), have reported timing chain issues. A stretched or broken timing chain can cause catastrophic engine damage. Regular oil changes and listening for unusual engine noises are crucial for prevention.

• DEF (Diesel Exhaust Fluid) System: The F30 335d relies heavily on DEF to reduce NOx emissions. Problems with the DEF tank, pump, or sensors are common and can trigger warning lights and limit performance. Maintaining the DEF system and using high-quality DEF fluid is essential.

Fuel Economy (EPA est.): The E90/E91 335d achieves an EPA-estimated fuel economy of 23 mpg city and 36 mpg highway. The F30 335d, designed with increased efficiency in mind, boasts an EPA-estimated 31 mpg city and 43 mpg highway. Real-world fuel economy can vary depending on driving style and conditions.

Which Years to Consider (and Why)

2009-2011 (E90/E91):

• Pros: More aggressive engine tuning, arguably more engaging driving experience, potentially lower initial purchase price.
• Cons: Higher risk of carbon buildup, swirl flap issues, and emissions system failures. Requires diligent maintenance and potential preventative repairs. Older technology compared to the F30.

2014-2015 (F30):

• Pros: Improved fuel economy, more modern interior and technology, generally considered more reliable than later F30 models concerning timing chain issues.
• Cons: Less raw power compared to the E90/E91, potential EGR cooler failures, DEF system complexities.

2016-2018 (F30):

• Pros: Latest iteration of the F30, potentially more features and updated styling.
• Cons: Higher risk of timing chain issues compared to earlier F30 models, potential EGR cooler failures, DEF system complexities. Requires careful inspection and maintenance history review.

Recommendation:

For enthusiasts prioritizing performance and willing to invest in maintenance, the 2009-2011 (E90/E91) models offer a rewarding driving experience. However, be prepared for potential carbon buildup, swirl flap issues, and emissions system repairs.

For those seeking a balance of performance, fuel economy, and modern features, the 2014-2015 (F30) models are a solid choice. Pay attention to the EGR cooler and DEF system.

The 2016-2018 (F30) models offer the latest features but come with an increased risk of timing chain issues. Thorough pre-purchase inspection and meticulous maintenance are critical.

Key Areas to Inspect Before Buying

No matter which year you consider, a thorough pre-purchase inspection is crucial. Pay close attention to the following:

• Engine: Listen for unusual noises, check for oil leaks, and ensure smooth acceleration. A compression test can reveal potential engine issues.
• Transmission: Ensure smooth and precise gear changes. Look for signs of slipping or hesitation.
• Emissions System: Check for warning lights related to the DPF, DOC, or DEF system. A diagnostic scan can reveal underlying issues.
• Cooling System: Inspect the EGR cooler for leaks. Check the coolant level and condition. Overheating can indicate serious problems.
• Suspension and Brakes: Evaluate the condition of the shocks, struts, and brakes. Listen for unusual noises during a test drive.
• Maintenance History: Review the maintenance records to identify potential problem areas and ensure that scheduled maintenance has been performed.

Frequently Asked Questions

Is the BMW 335d reliable? Reliability varies by model year. Early models are prone to carbon buildup and emissions issues, while later models can experience timing chain problems.

How much does it cost to maintain a BMW 335d? Maintenance costs can be higher than average due to the complexity of the diesel engine and emissions systems. Budget for regular oil changes, filter replacements, and potential repairs to the DPF, EGR cooler, and DEF system.

What is the best way to prevent carbon buildup in a 335d? Regular intake valve cleaning (walnut blasting) is the most effective way to prevent carbon buildup. Using high-quality fuel and performing frequent oil changes can also help.

Are swirl flap deletes recommended on the E90/E91 335d? Many owners opt for swirl flap deletes to prevent engine damage from broken flaps. However, this modification may affect emissions compliance and potentially reduce low-end torque.

Can I improve the fuel economy of my 335d? Driving conservatively, maintaining proper tire pressure, and using high-quality fuel can improve fuel economy. Regular maintenance, including air filter replacement, is also important.

What is the Diesel Exhaust Fluid (DEF) for? Diesel Exhaust Fluid (DEF) is used in the F30 335d to reduce NOx emissions. It is injected into the exhaust system to convert NOx into nitrogen and water.

Conclusion

Choosing the best year for a BMW 335d depends on your priorities and willingness to invest in maintenance. The E90/E91 offers a more raw driving experience but requires diligent upkeep, while the F30 provides improved fuel economy and modern features but may be susceptible to EGR cooler and timing chain issues. Thorough research and a pre-purchase inspection are essential for making an informed decision and enjoying the unique blend of performance and efficiency that the 335d offers.