Are BMW Reliable?

BMW as a Whole

BMW has been around for over 100 years and is one of the biggest names in the automotive industry. They offer a wide range with a focus on comfort and performance and are often viewed as luxury vehicles.

With German engineering being famous for reliability and efficiency, I wanted to look into BMW to see how well this translates into the actual vehicles.

What Engines do BMW Use?

BMW have a huge portfolio of engines behind them. Boasting 55 Petrol and 11 Diesel engines, your second hand BMW can have any engine from their huge list. You can view a full list of BMW engines here.

The main engines which we will focus on are the N47, N57 and B47. Regarded as some of the most problematic BMW engines, the N47 and N57 faced massive issues with the timing chain in particular. The B47 was introduced to replace the N47 but was found to face the same issues with the chain.

The N47 was in circulation during 2007-2014 and could be found in the following applications:

N47 Vehicle applications

 

The N57 was around from 2008-2020 and could be found in the following applications:

N57 Vehicle applications

 

Timing Chain Issues

When constructing the N47, BMW stated the timing chain would last the lifetime of the vehicle, which they claimed as 100,000 miles. With the intention of not being serviced regularly, BMW installed the chain at the back of the engine.

BMW N47 engine showcasing the difficult to access timing chain

Contrasting BMWs statement, the timing chain does need to be serviced just as you would with a timing belt. While it is stronger, the chain has as much potential to stretch and snap as a timing belt would. Requiring the entire engine to be removed, should the timing chain need to be replaced this suddenly becomes very labour intensive and expensive. A snapped timing chain is something that can be avoided with proper maintenance, however this is no longer a simple job.

Additionally, the plastic guides used can leave small fragments which contaminate the oil and lead to blockages. Ultimately, this can cause oil starvation and failure to lubricate the necessary parts.

Crankshaft Pulley Failures

One of the main issues when looking at BMW reliability is the quality of their crankshaft pulleys. BMW TVDs are constructed in a 3 piece design with a rubber insert in the middle. Over time this rubber degrades fairly easily, due to poor materials used, and ultimately causes the crankshaft pulley to come apart.

BMW Crankshaft pulley which has come apart. The photo showcases how the pulley will split into two parts.
Photo courtesy of Lewin Day from theautopian.com

This pulley is responsible for powering the alternator and water pump. If this part fails the driver may see warning lights indicating their battery is not charging or their engine is overheating.

While it’s not unnatural for rubber parts to degrade over time, there are a plethora of drivers reporting their pulleys failing prematurely. It’s indicative of a larger issue with their crankshaft pulley production and while most BMW drivers may not report any issues it’s something that they should all be aware of. The best way to compensate for this issue is to have the OE pulley replaced with one of higher quality.

GT Automotive Crankshaft Pulleys

At GT Automotive we stock a range of TVDs specially designed for BMW applications to exceed OE quality. We work closely with our factory to ensure that we deliver only the highest quality parts to the aftermarket.

View the range of BMW Crankshaft Pulleys here

Learn more about GT Automotive market leading Crankshaft Pulleys

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