Who hasn’t found himself in the situation where his car doesn’t start one morning on the way to work? If that didn’t happen to you, at least you’ve already had that fear. So when you hear an alternator noise on BMW 4 Series, you can already imagine yourself breaking down, stuck awaiting the tow truck. That’s why our team has decided to produce this article to support you locate the sources of alternator sounds. In this article, you will first discover the role and functions of the alternator in your BMW 4 Series and then what the causes and solutions to alternator noise on BMW 4 Series may be.alternator-noise-bmw-4-series

Role and alternator operation BMW 4 Series

Alternator role

Your alternator is an fundamental component of your BMW 4 Series. In fact, its goal is to provide power to your entire electrical system: headlights, interior lighting, signalling, computer… It will have the mission of charging the battery once the car is in motion, to provide power to the car in motion and to let you to always have a sufficient energy source to be able to restart the next time.

Alternator functioning

The alternator works on an electrical principle that has been used for decades, the principle of copper coil wound around a magnet . This coil while spinning creates electricity. It is the engine motor itself that will give the energy needed by the alternator to generate the energy, via the accessory belt or alternator belt. When your BMW 4 Series engine stops, the battery takes over to give the car with energy.

What are the different alternator noises or sounds on my BMW 4 Series and what are the causes?

I hear a knocking noise caused by the alternator of my BMW 4 Series

One of the typical noises of a tired alternator on BMW 4 Series is a knocking noise. This alternator sound on BMW 4 Series will most of the time show up when your engine is idling, it can be associated with voltage drops that could disturb the normal operation of electrical elements such as headlights for example. In many cases, it is a of both bearings of the alternator that is malfunctioning, to verify it, use a multimeter on the terminals of your car with the engine running and you must look for a value between 12 and 14.7 volts, which means that your alternator is charging your battery well. If the value is lower, the alternator of your BMW 4 Series is tired and you should think about replacing the bearing if it is the only cause otherwise the complete part.

I hear a grinding noise coming from the alternator of my BMW 4 Series

If you are in the situation where the alternator of your BMW 4 Series causes grinding sounds, in this circumstance you will have to check it more seriously. This indicator can testify as for the knocking sound of a tired bearing, but generally, we generally realise by looking more strongly that it is the accessory belt that is loosened or worn and is therefore the cause of it. In this circumstance, we advise that you look for advice this document to find all the necessary details to solve an accessory belt noise on BMW 4 Series.

I hear a loud noise from the alternator of my BMW 4 Series

Experiencing a loud noise from the alternator of your BMW 4 Series is quite typical, in fact, it emits an audible sound when creating the electrical pulses it generates. It is up to you to verify that the battery indicator light on your dashboard does not show up, and that you do not have a voltage drop when your engine is running (headlight or dashboard light that jumps for example. If this noise is too loud, we advise that you have a look this document to find other ways to solve problem of noises from front end on BMW 4 Series.