The BMW N20 engine, a 2.0-liter turbocharged inline-4 engine, is known to have timing chain-related issues, particularly in certain early production models. These problems are often attributed to the timing chain tensioner and the timing chain guide. If you’re considering a vehicle with a n20, it’s important to see if the timing chain has been addressed and factor that into your buying decision. Here’s a closer look at the issues:
Common Timing Chain Problems in the N20:
- Timing Chain Tensioner Failure: One of the most common issues with the N20 engine is the failure of the timing chain tensioner. The tensioner is responsible for maintaining the correct tension on the timing chain. Over time, it can wear out, leading to inadequate tension. This can cause the timing chain to slacken, resulting in a rattling sound from the engine, particularly on cold starts. If left unaddressed, this can lead to serious engine damage.
- Timing Chain Guide Wear: The timing chain guides, which help direct the movement of the chain, can also wear out over time. When these guides fail, the chain may not run smoothly, and this can lead to misalignment. A worn or broken timing chain guide can result in severe engine damage, including valve and piston contact, which could lead to catastrophic engine failure.
- Engine Misfires and Rough Idle: A worn-out timing chain or tensioner can cause misfires, poor engine performance, or a rough idle. If the timing chain is not correctly tensioned or aligned, the engine may fail to run as smoothly, affecting overall driving experience.
- Warning Signs:
A rattling or clattering noise from the engine, especially at startup
Check engine light due to misfires or timing-related issues
Poor engine performance, hesitation, or rough idling
Why the Timing Chain Issues Occur:
- Early N20 Engines: The issues were more prevalent in early N20 engines (around 2012 to 2014 models), as BMW initially used a weaker timing chain tensioner design and lower-quality materials in some components.
- Extended Oil Change Intervals: BMW’s extended oil change intervals might have contributed to premature wear on the timing chain system. Regular oil changes with high-quality synthetic oil are crucial for maintaining the timing chain’s longevity.
Solutions:
- Upgraded Components: BMW has released updated timing chain tensioners and guides to address these issues. Some owners have had their timing chains and tensioners replaced under warranty, especially if they experienced early failures.
- Regular Maintenance: Regular oil changes and using high-quality oil can help prevent premature wear of the timing chain system. Some owners choose to shorten their oil change intervals to avoid the buildup of sludge that can negatively impact the chain.
- Preemptive Replacement: If you’re buying a used BMW with the N20 engine, it’s a good idea to inquire about the history of the timing chain system, as replacing the timing chain and tensioner can be an expensive repair. Vehicles in the 80,000-120,000 mile range are in the sweet spot for timing chain replacements.
While the N20 engine has generally been regarded as a reliable powerplant, it does have some known timing chain issues, particularly in earlier models. These issues can lead to significant engine damage if not addressed in a timely manner. Regular maintenance, staying on top of oil changes, and addressing any early signs of timing chain problems can help prolong the engine’s life and avoid costly repairs. Try to keep oil service intervals to 4,000-6,000 miles. By shortening the oil service interval, you keep the oil fresher which better lubricates and protects the engine. With former BMW dealer techs on staff, we can help you with any n20 issue that may arise. Give us a call to schedule an appointment, if you’ve got a n20 the sooner the better!
