The BMW M550I is a comfortable, high-performance, spacious, and technologically advanced luxury sedan. It features the N63 engine, which is one of the most powerful BMW engines on the market. But like most luxury cars, it also comes with a ton of issues that users should know about. Regardless, what are the common problems with the BMW M550I?
The common problems with the BMW M550I are timing chain failure, fuel injector failure, ignition coil issues, excess oil usage, and spark plugs failure. Other issues are water pump failure, leaking valve stem seals, and fast battery drainage. As usual, most of these issues can be avoided through regular maintenance and repair.
What are the common problems with BMW M550I?
Excess oil consumption
The first common problem that most BMW M550i users face is excess oil usage. This problem comes from the design of the engine with the turbos being in the middle of the valley of the engine. Additionally, drying out gaskets can also cause oil loss, which leads to excessive oil consumption.
It is estimated that this model consumes at least 1-qt per 600 miles, which is way above the average of 1-qt per 1000 miles.
Timing chain failure
Another common problem that BMW M550I users experience is timing chain failure. BMW admitted that the N63 engine has a timing chain problem. It was detected to stretch and wear out prematurely, causing reduced engine performance. If you discover that your car has this issue, fix it as soon as possible to prevent costly engine repair.
Fast battery drainage
The BMW N63 engine has a problem with eating up batteries. Therefore, the manufacturer recommends changing the battery during every oil change. This issue came along after BMW tried making the N63 engine efficient. Nonetheless, even though it helped the car to become more efficient, it uses a lot of battery power that ends up draining it.
Fuel injector failure
This is one of the problems that BMW M550i users report in the early stages of owning this car. Many users have reported having a bad fuel injector as early as 20,000 miles. Some of the signs of a bad or failed fuel injector are poor acceleration, engine misfires, rough idle, black exhaust tips, and the check engine light.
If you notice any of the above signs, know that it’s time to replace the fuel injector. Nonetheless, these can be signs of bad spark plugs or ignition coils.
Spark plugs failure
If the spark plugs on your BMW M550I go bad, you will start to have engine misfire, hard-starting engine, rough idling, and engine knocking. It is one of the first problems that BMW M550i users will experience. It normally starts happening after hitting over 30,000 miles. Replace the bad spark plugs with good ones for efficient performance.
Leaking valve stem seals
Valve stems seals fail on the BMW M550I because of the high heat given off by the exhaust and the turbos in the valley of the engine. Signs of leaking valve stem seals include excess oil usage and white smoke coming from the tailpipes. If you have this problem, you should replace the bad valve stem seals with good ones. The only challenge is that you have to drop the engine.
Ignition coils problems
As the spark plugs, ignition coils also start going bad after covering a few miles. It is recommended to check your ignition coils every 45,000 miles. Signs of a bad ignition coil include engine misfire, poor fuel economy, loss of power, and backfiring. Replace the ignition coils on your BMW every 45k miles.
Water pump failure
The major cause of water pump failure in the BMW M550I is wear and tear. When your BMW hits over 80,000 miles, you will likely start having water pump problems. Failure to replace a bad water pump can bring about engine cooling problems. So, it should be replaced as soon as possible.
FAQ
Is the BMW M550I reliable?
No, the BMW M550I is one of the least reliable cars on the market. Generally, the BMW 5-Series is less reliable than most BMW Series. Not only does the BMW M550I have a lot of problems, but the cost of its parts is high and so is the cost of service. And since it comes with lots of advanced features, many things can easily go wrong.
After how many miles does the BMW M550i start having issues?
It depends on how well you maintain the car. Some BMW M550I users have reported problems as early as 30,000 miles, while others experienced issues after hitting 50,000 miles. With proper care and maintenance, you may start experiencing serious problems from 100k miles.
What is the high mileage for the BMW M550i?
The high mileage for BMW M550i is around 150,000 miles. However, this applies to well-maintained cars as most M550Is start having serious issues after clocking over 100k miles. But with proper maintenance and care, they may start developing problems after hitting over 150k miles.
So, if you plan to buy a used BMW M550i, get one with less than 150k miles. As a result, you won’t have to spend a lot on repair and maintenance.
Is BMW M550I expensive to maintain?
The BMW 5-Series is one of the most expensive BMW executive sedans to maintain. And since BMW M550i is a high-end model of the BMW 5-Series, it is even costlier. Approximately, the user will have to spend at least $1,200 a year to repair and maintain the BMW M550i.
Which engine is better – the N63 or B58 engine?
It depends on what you’re looking for. The N63 engine is more powerful and fun to drive, but the B58 engine is more reliable and has fewer problems. On top of that, the N63 consumes more fuel and oil than the B58. The S58 is the performance version of the B58 engine.
Final thoughts
Now that you know some of the common problems the BMW M550I undergoes, it is crucial to take good care of your BMW executive sedan to prolong its lifespan. With proper care and maintenance, most of the problems we’ve highlighted above can be avoided.
All in all, BMW M550I is an excellent, luxurious, stylish, comfortable, safe, spacious, and high-performance car. On the contrary, it has a high initial price, it is not efficient, and reliable. Nonetheless, it is ideal for people who are ready to spend to enjoy a luxurious and high-performance ride.