# Important Aspects Contributing to the Long-Term Dependability Problems of the BMW N47 Engine
Launched in 2007, the BMW N47 engine is a four-cylinder turbocharged diesel powertrain that has been installed in various BMW models, such as the 1 Series, 3 Series, 5 Series, and X Series. Renowned for its remarkable fuel efficiency, robust torque output, and overall performance, the N47 engine has become a favored option among BMW fans. Nonetheless, in spite of its merits, the N47 engine has developed a reputation for long-term dependability challenges that have resulted in many owners confronting steep repair bills. This article investigates the primary reasons behind these dependability issues and examines their influence on the engine’s reputation.
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## 1. **Flaws in Timing Chain Design**
A major and extensively talked-about concern regarding the BMW N47 engine revolves around its timing chain design. The timing chain is an essential part that coordinates the rotation of the crankshaft and camshaft, facilitating proper engine function. Unlike numerous engines where the timing chain is found at the front, the N47’s timing chain is situated at the rear of the engine, complicating and escalating the expenses of maintenance or repairs.
### Frequent Issues:
– **Early Timing Chain Wear:** The timing chain in the N47 engine tends to stretch and wear prematurely, often manifesting between 40,000 to 100,000 miles. This may result in a rattling sound, subpar engine performance, and, in serious instances, catastrophic engine failure.
– **Insufficient Lubrication:** Inadequate lubrication of the timing chain components has been recognized as a factor contributing to premature wear.
– **High Repair Expenditures:** Given the rear location of the timing chain, repairs frequently necessitate engine removal, greatly inflating labor costs.
BMW has acknowledged this predicament and released technical service bulletins (TSBs) in certain regions, yet numerous owners have dealt with out-of-warranty repair expenses that can surpass several thousand dollars.
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## 2. **Failures of the Turbocharger**
The turbocharger of the N47 engine represents another significant area of concern. Although turbochargers are intended to improve engine performance and efficiency, they also endure high levels of stress and heat, which can result in premature failures.
### Frequent Issues:
– **Oil Supply Deficiencies:** An inadequate or inconsistent oil supply to the turbocharger can result in excessive wear on the bearings, leading to malfunction.
– **Carbon Accumulation:** Over time, carbon deposits can build up within the turbocharger, diminishing its efficiency and potentially causing mechanical failures.
– **Overboosting Issues:** Certain owners have reported turbocharger overboosting problems, which can place additional strain on the engine and lead to further complications.
Regular oil changes and appropriate maintenance can assist in alleviating turbocharger issues, but failures may still arise unexpectedly, resulting in expensive repairs.
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## 3. **Problems with the EGR (Exhaust Gas Recirculation) System**
The EGR system integrated into the N47 engine aims to minimize nitrogen oxide (NOx) emissions by recirculating a portion of the exhaust gases back into the engine’s intake. While this system serves a crucial purpose in adhering to emissions regulations, it has also been a source of reliability issues for the N47 engine.
### Frequent Issues:
– **Carbon Accumulation:** The EGR valve and cooler are susceptible to carbon deposits, which can obstruct airflow and cause diminished engine performance or even a total EGR system failure.
– **EGR Cooler Leaks:** Some N47 engines have dealt with EGR cooler leaks, which may lead to coolant loss and, in extreme situations, engine overheating or hydrolock.
– **Fire Hazard:** In 2018, BMW issued a recall for specific diesel models, including those equipped with the N47 engine, due to a potential fire hazard linked to the EGR cooler.
Routine cleaning and examination of the EGR system can help prevent these problems, yet the system’s fundamental design makes it vulnerable to recurring issues.
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## 4. **Crankshaft and Main Bearing Complications**
The crankshaft and main bearings are vital components of any engine, and the N47 engine has been recognized for experiencing issues in this domain as well.
### Frequent Issues:
– **Excessive Wear:** A number of N47 engines have encountered pronounced wear on the crankshaft and main bearings, leading to knocking sounds, diminished performance, and, in severe cases, engine failure.
– **Oil Starvation:** Insufficient lubrication can worsen wear on these components, especially if the engine oil is not regularly changed or if low-quality oil is utilized.
These complications are less prevalent than timing chain issues but can still incur considerable repair expenses when they arise.
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## 5. **Blockages in the DPF (Diesel Particulate Filter)**
The Diesel Particulate Filter (DPF) is yet another emissions-related component that has caused significant trouble for N47 engine owners. The DPF is designed to trap and incinerate soot particles from
