BMW 740Li xDrive Loss of power Inspection at your home or office.

Common reasons for this to happen:

• Defective fuel pump or filter: Since the fuel pump is responsible for supplying your vehicle with fuel, it can cause a loss of power when it begins to wear out or when the in-tank filter becomes clogged and prevents the free flow of fuel. When the fuel pump is failing or unable to push fuel through the filter, your car will sometimes make sputtering noises at high speeds, act like it is going to stall as you accelerate from a stop, or simply stop running when it is under the stress of a hill or heavy load.

• Vacuum leak: When a vacuum leak is present in your vehicle, it interferes with the computer’s ability to regulate the air-to-fuel ratio, which can sometimes lead to power loss. Such leaks will frequently cause the Check Engine” light to come on, and you can usually hear a hissing noise come from the engine area if you listen closely under the hood of your vehicle.

• Ignition system: When the ignition system is malfunctioning, your vehicle may also have problems starting periodically in addition to power loss. Frequently, a tune-up will solve this problem, but it is important to have a qualified mechanic with the proper diagnostic tools check the system as a whole. Modern tune-ups typically involve replacing fewer parts than years past, but with more attention being paid to the fuel injection system at the same time.

• Timing belt or chain: A worn timing belt or chain can cause the valves on your engine to open and close at the wrong intervals, sometimes resulting in a loss of power. When the timing is off, it is frequently accompanied by a slight clattering noise at the front of the engine.

• Catalytic converter: When the catalytic convertor fails or become clogged, it prevents proper air flow through the engine, which can cause power losses. Aside from a loss of power, your car may also run at a higher temperature than usual or have an erratic idle. A mechanic can easily check your catalytic convertor with a vacuum gauge to determine if it is functioning properly.

• Airflow sensor: When your airflow sensor is failing or dirty, it can send wrong signals to your engine’s computer that can result in power losses while accelerating. This type of issue usually causes your Check Engine” light to come on and your vehicle to behave sluggishly even when there is power.