Experiencing noises from your car frequently is never reassuring, so listening noises on your BMW 4 Series suspensions when you go over a speed bump can be stressing. This indicator may be a sign of a small issue as well as a warning of a much larger repair to come. Whatever the case, it is important to check the cause and take the necessary actions to correct the issue, it is with this objective in mind that we wanted to write this document to help you see more clearly. We will first see the possible reasons for a crack when the speed bump passes, after that, what can be the reason of a squeaking noise when a speed bump is being passed and finally what to do if you have another noise when a speed bump is passed.suspension-noise-bmw-4-series

Suspension cracking noise BMW 4 Series

Check BMW 4 Series suspension

If you encounter a suspension noise when you pass a speed bump on your BMW 4 Series, and it is characterized by a “clack” or cracking, it is highly plausible that your suspension block is the origin of it. In fact, it may be the suspension cups, which, when they are outdated, have the rubber (silentblock) that acts as a buffer and shock absorber for the upper part of the suspension that no longer fulfils its job during small bumps that compress the suspensions. To check if this is the issue that concerns you, take a dented road and listen to the noise coming from your front axle as you pass over holes. If it is indeed the cups, think of replacing them fairly quickly or you may damage other parts and have to make more important vehicle repairs.

Check the cardan shaft

If you are here because you have searched for “BMW 4 Series suspension noise” and the suspension is not the cause of your problem, it may be that the cardan shaft is responsible. In fact, when the cardan bellows get outdated and the dirt/dust accumulates inside them their functions is degraded and it is possible to experience a sound when they are in torsion. To check this, you can try both types of torsion, first vertical with suspension compressions on the speed bump passages, and horizontal when you are going to make a turn at low speed. If it cracks in these two circumstances you should consider changing it or them. If you have the feeling that this noise is more like a a loud noise on BMW 4 Series, don’t hesitate to read this article.

Check steering hinges/stabilizer bar

Finally, when you recognise a suspension noise when your BMW 4 Series passes over a speed bumps, it is possible that the hinges or the stabilizer bar are responsible. Just like the gimbals, the steering part is mobilized when you adjust direction. If this is the case, the parts that may have been affected by regular wear and tear or impacts (e. g. sidewalks). The steering hinges, the stabilizer bar hinges. can be the origins of your noises, to check it, place it under the automobile and apply twists on each of its elements to check that there is no special play on one of them, they are expected to endure you quite strongly over their entire travel. Remember to take your vehicle to your mechanic or replace them if they are involved.

squeaky noise speed bump BMW 4 Series

Check the stabilizer bar

If, alternatively, you have a noise that is more like a squeak when you go over a speed bump with your BMW 4 Series, it is plausible that it is the stabilizer bar itself that is involved. In fact, abnormal/pronounced wear of the latter can cause uncommon friction which can create this squeaking noise. Remember to check by passing under your automobile the condition of the paint on your bar which will indicate if there is friction. Second plausible explanation, it may be your stabilizer bar silentblocks that are dried out and bring on noise, in which case take them out from the cradle and grease them, this should solve the issue.

Check engine silentblocks

Finally, last case that we can check together, it is the engine silentblocks, in fact, these silentblocks operate as pads/shock absorbers between the engine and the cradle of the car, a evident weakness of these will generate a subsidence and therefore a space between the engine and the silentblocks, it may happen that a squeaking noise appears when you pass a speed bumps or any holes with your BMW 4 Series. To swap them go to your technician.

Other speed bump noise BMW 4 Series

If, despite all its assumptions, you still can’t locate the origin of the noise your BMW 4 Series makes when you pass a speed bump, we encourage you to consult this content on a loud noise on BMW 4 Series or to visit your mechanic in order to carry an in-depth check on your BMW 4 Series and discover this issue.