BMW 335i: Problems after 100K Miles and Overall Durability

The BMW 335i excels in safety features, engine performance, and technology, but its durability is always up for debate. The BMW 335i may encounter numerous problems after 100k miles impacting its overall durability. Some of these common problems after 100k miles include oil leaks, cooling system failure, excessive suspension wear, and high-pressure fuel pump failures.

To maintain reliability, owners should prioritize timely maintenance. Overall, Despite these problems, proper care and attention can help prolong the BMW 335i's longevity and ensure continued performance on the road.

Common Problems After 100K

1) Cooling System Issues

In a high-performance car like the BMW 335i, the cooling system plays a crucial role to keep engine temperatures in check. Just like any other car, the cooling system is responsible for dissipating the heat produced by the combustion engine. The cooling system of the BMW 335i is made of multiple components which include the water pump, radiator, thermostat, cooling fan, and hoses, all working in sync to regulate engine temperature.

When your BMW 335i inches close to the 100K mark, various parts of this cooling system would start to fail. And even one of the parts that make the cooling system fails, the entire cooling process will crumble. 

As your BMW 335i ages, it is crucial that you stay vigilant of any problems in your cooling systems. Continually driving with cooling system issues can ruin your engine, leading to engine repairs or even a complete engine replacement.

Keep a look out for the following symptoms that'll indicate that your cooling system is faulty:

• Engine Overheating -This is a no-brainer. As soon as your cooling system fails, your engine will start to overheat. This will be followed by a warning light on your dash. If your engine is overheating during idle, which is very common when looking at cooling system issues, chances are that your thermostat or cooling fan has failed.
• Coolant Leaks - The coolant that is pumped through your engine circulates at high pressure. So, as the parts of the coolant system wear down, the pressurized coolant might seep through. Even hoses tend to get damaged allowing the coolant to leak. Look for visible signs of coolant leaks and puddles of coolant on the ground as you pull out your car. Also, if you are regularly running low on coolant, there is a good chance that you are experiencing coolant leaks.
• Reduced Engine Performance - If your BMW 335i engine overheats, you'll see a significant drop in performance, fuel efficiency, or misfires.

2) Turbo Charger Failures

The reason why the BMW 335i boasts impressive numbers is partially because of its twin-turbo kit. Understanding how turbos work is simple. By forcing more air into the combustion chamber, it is able to increase efficiency and overall performance. 

The BMW 335i has a twin-turbo setup, meaning it has two turbochargers. One of these tubo chargers known as "low pressure" is capable of providing immediate power and reducing turbo lag, at low RPMs. The larger turbo of the two which is the "high pressure" comes into play at higher RPMs, delivering greater power for higher-speed driving. These two turbos of the BMW 335i work in sync and effectively manage airflow ensuring optimal performance and smooth power delivery no matter the driving conditions. 

But as you close in on the 100k mile mark on your BMW 335i, the wear and tear on these turbos starts to show, and will eventually fail. Since the BMW 335i engine is tuned to work with the turbos, their failure will significantly affect your engine. You will lose performance and efficiency and if not dealt with, eventually you'll lose your engine. 

Here are a few symptoms to keep an eye out for:

• Excessive Smoke From Exhaust - Once your turbos fail, you might notice black or blue smoke coming out of your exhaust. Black fumes indicate that your fuel-to-air ratio is off. In this case, your fuel is not getting enough oxygen resulting incomplete combustion. Blue smoke is a result of engine oil seeping into the combustion engine, which is also a symptom of a worn turbocharger.
• Significant Loss In Power - The BMW 335i will feel sluggish while accelerating and also struggle to reach higher speeds without a properly functioning turbo kit.
• Loud Whining Noise - When the bearing on your turbocharger is damaged, you'll hear loud whining noises when you try to accelerate.
• Check Engine Light - Though this can pop up for a variety of issues, a scan would allow you to pinpoint the cause. Since a malfunctioning turbo directly affects the engine, the check engine light will illuminate.

3) High-Pressure Fuel Pump Failure 

The early models of BMP 335i are notorious for their HPFP failure. To be more specific, the models between 2007 and 2010 which came out with the N54 engine had an issue with the HPFP. If you have a BMW from this time period, the risk of HPFP failure increases with your mileage.

The fuel pump is responsible for delivering fuel to the combustion chamber. The HPFP is basically a fuel pump on steroids, which is supposed to meet the increased demand of the BMW engine.

BMW addressed this issue with a recall for all 335i models with the affected engine. Basically, when the fuel pump fails, the supply of fuel to the engine is reduced or cut off totally. To quote BMW itself, "Ignoring this recall can pose drivability issues and even prevent the vehicle from starting properly". BMW also extended the warranty to 10 years/ 120,000 miles and will cover the HPFP of all affected models. This is more than double the standard warranty for the BMW 335i.

Here are a few symptoms of a failing HPFP:

• Misfires - Misfires happen when fuel delivery is insufficient or inconsistent. A malfunction in the HPFP will fluctuate the fuel delivery. This fluctuation in fuel delivery will also result in rough idling.
• Stalling - As the fuel pressure drops, the engine will be prone to stalling. This is more common at low speeds or when coming to a stop
• Reduce Engine Performance - This needs no explanation, when there is not enough fuel to burn, your performance will drop.

4) Electrical Issues

The BMW 335i houses an intricate electrical system that contributes to its comfort, performance, and safety features. As a modern luxury sports sedan, there are numerous advanced electrical add-ons within the vehicle. A few examples are the iDrive Infotainment System, Advanced Driver Assistance Systems (ADAS), comfort and convenience features such as keyless entry, power windows, automatic climate control, electronic seat adjustments, and an advanced lighting system.

As with any complex electrical system, with time problems start to surface:

• Electric Windows - Many owners have reported issues with the electronic windows, especially after logging close to 100k miles. This is caused by the electrical motors experiencing wear with age.
• Battery And Charging System Issues - The BMW battery and charging system is quite well-built. Yet, just like any other vehicle, as you edge towards the 100k mile mark, naturally they start to fail.
• Sensor Failures - The BMW 335i depends on numerous sensors for optimal performance and to deliver the comfort you deserve. From time to time, these sensors fail disrupting operations.

5) Oil Leaks

Even though BMWs are known for their engineering excellence, oil leaks are a common issue with the BMW 335i over time. Parts in your engine develop leaks as a result of wear and tear as well as age. The gaskets and seals in your BMW 335i engine tend to give out as you put in the miles on it. Usually, it's the oil filter housing gasket, crankcase ventilation system, or turbocharger lines.

The importance of engine oil cannot be overstated. Without it, your engine will simply grind and break apart. So it is important to diagnose the symptoms early and get the problem solved at its early stages. Here are some signs to keep an eye out for:

• Puddles Of Oil Under The Car - Noticeable spots of oil under the car after pulling out your car is definitely an indicator of oil leaks.
• Burning Smell - The oil directly doesn't fall to the floor. While it lingers in the engine, the high heat can burn the oil. So, if you are vigilant, you might notice burning smells when there are oil leaks.
• Low Oil Levels - Your dash will warn you when you are running low on oil. It's normal to top off your oil once in a while. But if this is happening often, it's almost a guarantee that your engine is leaking oil.

Overall Durability Of The BMW 335i

The BMW 335i has cemented a name as one of the best luxury sports sedans in the market. Despite encountering certain issues over time, it exhibits commendable durability. Though you may encounter certain problems as you inch closer to the 100k mile mark, these are nothing significant. As long as you diagnose the problem early on, they are easy repairs that won't cost a fortune. And most of these problems are to be expected from a high-performance machine like the BMW 335i.

Many owners have reported surpassing 100,000 miles and some have even reached 150,000 to 200,000 miles using their BMW 335i. With the build quality that goes into the BMW 335i, it's no surprise that the machine is durable. At the end of the day, it comes down to maintenance. With proper maintenance and care, the BMW 335i can last a lifetime.