DIESEL PROBLEMS

Some models in the BMW 4 series have diesel engines with high efficiency. However, these models experience clogged exhaust gas recirculation (EGR) filters due to carbon build-up in the valve. This same problem can also affect the diesel particulate filter (DPF). Clogged filters can lead to the destruction of the valve and filter. Recurrent clogs of the EGR and DPF valves will interfere with the vehicle’s operation, leading to faulty engines. In addition, filter clogs cause an increase in vehicle emissions and a reduction in power, acceleration, and fuel efficiency.

AUTOMATIC TRANSMISSION PROBLEMS

It is not uncommon to see BMW 4 series with transmission problems. Transmission problems present symptoms like delayed engagement when changing gears, noise, difficult shifting, etc. There are different causes of automatic transmission problems. One of the causes of the problem is low transmission fluid level resulting from fluid leakage. If the leakage continues, it will affect the vehicle’s operation. Also, defective mechatronics units can affect the automatic transmission of a vehicle. For example, when the mechatronic unit starts experiencing faulty solenoid, valve body gaps, and faulty temperature sensors, there is a problem. Automatic transmission problems are easy to detect. Early detection helps to prevent further damage to the components of the vehicle.

CRANKSHAFT POSITION SENSOR PROBLEMS

The combustion engine uses the rotational energy of the crankshaft to perform well. The energy powers the wheels of the car drivetrain to move the vehicle in the correct direction. On the other hand, the crankshaft position sensor detects the rate at which the crankshaft spins. The sensor then sends this information directly to the car’s engine control module.
Some models of the BMW 4 series have crankshaft position sensor problems. Over time, the sensor fails to work properly by failing to send signals or sending false signals. When this happens, the transmission control unit senses a fault and automatically shifts to the “limp home” mode. This problem will affect the control unit and ultimately affect the overall operation and performance of the engine. The major symptoms of faulty crankshaft position sensors are long crank time, engine vibration, and engine stalling. In some models, when the sensor is bad, the engine will crank and not start._

ADJUSTABLE REAR SUSPENSION PROBLEMS

An adjustable rear suspension enables the driver to achieve flexible lowering with the adjustment options. It also enables the driver to adjust the compression when the need arises. The suspension consists of coil springs, torsion bars, shock absorbers, control arms, and others. During a ride, the coil compresses when there are bumps and stretches out when the road is smooth. In addition, adjustable rear suspension enables a stress-free ride.
Driving a car with a bad suspension will make driving difficult because of the rough ride. For example, the adjustable rear suspension of the BMW 4 series often goes bad. When this happens, the car experiences broken strings, broken shock absorbers, broken wheels, and other problems.

THUMPING NOISES

BMW 4 series often produce thumping noise due to worn-out tires or a shifted belt. This noise indicates the tires have low pressure. Warped brake rotors also cause thumping noise. Friction can occur when braking and when this continues, the rotor surfaces become uneven. The brake then gives a loud thumping sound when engaged. Loose suspension parts can also give a thumping noise. If the noise is coming from the vehicle’s front end, then there is likely an issue with the suspension.