It is never enjoyable to experience a noise in your vehicle that you don’t know the starting point of. So, what if you detect a loud noise that lasts on your smart forfour? It is extremely possible that this is a minor issue, but before beeing sure, it is better to execute some checks. Whether that loud noise comes from the front of the automobile, from the rear, whether it happens when you accelerate or when you are parked, our team has written this content to help you fix it. First, we will detail the possible causes for the issue according to when loud noise shows up on your smart forfour, and then we will concentrate on the region of origin of the noise. In any case, if this noise continues, follow these suggestions to help you find the source.
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When does my smart forfour make a loud noise?
One way to detect a noise from your smart forfour is to define when it occurs. Indeed, some complications can be connected to components that are only stressed under certain occasions. It is this approach that we will focus on in this first part.
Loud noise smart forfour when accelerating
Loud noise on smart forfour that takes place when you are accelerating can be symptomatic of multiple failures. In fact, if you feel a noise that is louder and louder when you accelerate, it can come from a faulty turbo that will induce a much higher noise than during normal operation. Additionally, it is also highly possible that loud noise on your smart forfour is related to a wheel bearing, which is one of the most common causes of these types of manifestations. Another alternative is that your exhaust pipe may have holes or a collar may have become loose. Finally, it is also possible that the issue may come from a deformed tire or an unbalanced wheel that will tend to vibrate as it gains speed.
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When my smart forfour is stopped
If your smart forfour makes a loud noise while not accelerating, engine on, the issue may be related to poor air intake. An air intake hose that has come loose or has a hole in it may be the cause.
Where does loud noise come from on my smart forfour and how can I be sure of its origin?
Now that we have determined the origin of the sound, we will focus on the verification stage to be sure that this is the matter you are enduring.
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The loud noise comes from the wheels of my smart forfour
As we have seen earlier in this article, loud noise from the wheels of your smart forfour may be related to two main problems. If it is one of your tired bearings, it will tend to make a thumping noise that intensifies when it is under stress (spins faster and faster). So remember to verify by driving “fast” (neutral gear on and window open to hear only the noise of the wheels) that the noise is located here, if this is the case change it or them as soon as possible. If it is a deformed tire, make sure to visually check the entire tread area for linearity. If it is the balancing of the wheels of your smart forfour that is the matter, you will tend to feel a vibration in the direction of the vehicle as you go faster. In both circumstances, you will have to go to your mechanic to swap the tires or do a balancing.
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The loud noise comes from the engine of my smart forfour
In case you have recognized loud noise as coming from the engine of your smart forfour, the two most likely causes are turbo and air intake. In the first case, a turbo failure may also be connected to a compression loss during the engine ramp-up phase, so you should encounter a power loss during your acceleration. If the loud noise on your smart forfour is related to air intake, the control will be done mainly visually, check all your air intake hoses by a visual control in your engine block to be sure that it is not damaged or disconnected which would induce an air intake, if it is just disconnected you can reconnect the air intake tubes yourself. Then verify that the engine idle speed is not random. In case you confirm one of these two problems, take your vehicle to your service garage .
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Loud noise comes from the exhaust pipe of the vehicle
If the noise you have found comes from the exhaust pipe of your smart forfour, it is highly possible that you have rust if your automobile is old and has created holes in it over time and therefore generates a very high noise close to aircraft noise on your smart forfour, that a part has been cut off due to wear, or, finally, that a clamp has become loose due to vibrations. To validate this, get help from someone who will stand under the automobile while you accelerate to find the exact area of origin of this noise. If it is a hole, you can repair it with a putty provided for this purpose, or, if it is a collar, “reattach” it. If it is cut or the hole is too big, it is better to get closer to your mechanic.
