The car ages quickly. Even faster the interior stuffing deteriorates - from the seat mechanisms, their upholstery, door and ceiling trim elements to various keys, buttons, plastic levers, handles. All this, to use formal terminology, wears out: driving a car even on quite decent roads begins to be accompanied by extraneous noises. The car enthusiast hears creaks, knocks and even grunts. What is the root cause of the sad metamorphosis? It seems that the possibility of a car degenerating into a mobile noise orchestra is primarily determined by the culture of its design - what is called a school. But schools, as we all understand, are different.
At the same time, the car's transition to this state can accelerate (slow down) by the actions of the owner himself, and they, the owners, are also different! One takes care of the car, watches its every whim, the other treats it like an enemy who has been captured.
But let's get back to the school of design. If you remove the door trim of an old one - "Saab", for example - you will see all sorts of levers, rods, cables, etc. The parts are flimsy, and they are attached "simply" or "very simply"! It seems that the designer was concerned that the mechanics would not rattle on the day the car was sold.
One of the most common causes of extraneous noise in the cabin is the loosening of connected parts due to their vibration wear. In moving units, wear from the mutual movement of parts is added to this.
Why, for example, does an "itch" of some decorative panel arise if it is tightly and immobilely connected to the base of the body or door? In fact, both the panel and the base vibrate, and often in different ways. This means that vibrational movements occur in their contact, wearing out the material. Then comes the vicious circle: more vibrational movements - more wear, louder noise.
Vibration wear of some plastic parts can be indicated by characteristic dust in contact areas, traces of mutual abrasion. Eliminate vibration displacements – wear will disappear.
Vibrational movements of parts such as interior decorative door panels can often be minimized by using additional fasteners, such as self-tapping screws. Sometimes it is done differently: a gasket made of foam rubber, sponge rubber, latex is installed between the panel and the door - materials that dampen vibration well.
How to deal with this has already been said. There is another method, tested by experienced car enthusiasts: the panel from the inside is pasted with an additional layer of noise insulation - even an old blanket. It is a labor-intensive matter, but those who decide to do it will be rewarded: the knocks are muffled almost completely.
In general, when you have to fight against noise caused by vibration of any panel, you should not treat it as a simple, easy matter, especially if the vibration of a rigid panel is not damped in any way (that is, it does not go out). Here, even additionally strengthening it with self-tapping screws, you may not achieve the desired results - having stopped "buzzing" at one speed, the panel may give an even more nasty voice at another. Using soft pads usually gives a positive effect.
Having mentioned the word "vibrations" so many times, it would be a good idea to say what kind of vibrations we are talking about. Unfortunately, various parts in the car interior, with different sizes, weights, rigidity, etc., also have their "favorite" vibration frequencies, which they readily respond to with "itching", knocking, rustling, etc. The vibrations themselves are caused by the operation of the engine, gearbox, transmission, wheel rotation, and finally, road irregularities. The frequency spectrum is so rich that any part, having received illegal freedom to vibrate, will certainly find "its" frequency.
This freedom has to be limited one way or another. Is a switch vibrating? Glue a thin strip of foam rubber to it or press it with an additional spring. Does the rod inside the door rattle? Support it with a pad made of the same foam rubber... or lightly tie it to the door frame with an elastic band.
If you look under the dashboard, you will see a picture of complete chaos: wire harnesses and individual wires, numerous electrical connectors, cables. Nearby are instruments and switches. There is also a collection of ownerless bolts and nuts that got here during the assembly of the car. All this rattles, clanks, especially in winter, when the wire harnesses are hard as a stick from the frost, and just like it, hit the parts of the structure. That is why many car enthusiasts literally stuff the space under the dashboard with foam rubber or latex.
By the way, additional noise insulation of the engine compartment and the space under the dashboard also gives amazing results. This is done with a piece of foam rubber glued to cardboard, which is laid from the pedals up to the edge of the "dashboard". It is clear that such a "muffler" must be securely fastened and not interfere with control.
Original can be found on the website: MERCEDESMAN.ru
The noise in the car's interior is largely explained by the properties of the materials used. Unfortunately, parts are often made of plastic, which is not wear-resistant, fragile, etc. Naturally, the "loosening" of a unit assembled from them can occur very quickly.
If the parts operate in conditions of even slightly elevated temperatures, it is important that they do not warp or shrink. In fact, we see this process in any of our cars.
A special type of noise is creaking. The causes of creaking can be very different, but they all have one root cause - the movement of one part relative to another in a pressed state and the work of friction forces. Why, for example, wouldn't the edge of the dashboard creak if the door is tightly pressed against it when closed? The entire body "breathes" on uneven roads, the parts move relative to each other, causing a squeak. It will disappear if you manage to eliminate the "illegal" contact. Most often, this involves loosening the fastening screws and moving the dashboard as much as necessary.
The seat springs have an "anti-squeak" coating where they contact the frame. But its layer is rather fragile, it wears out. And here you have it - a squeak. There are different ways to eliminate it. One puts a plastic tube on the spring, another winds an insulating tape, a third lubricates it with graphite grease. All the methods are rather frivolous - these measures do not last long.
The best way to eliminate creaking in hinge joints is to periodically apply graphite grease.
Another type of creaking is an extremely unpleasant sound that occurs when the heater fan is turned on, when the electric motor shaft rotates in the stator bushings without lubrication. There is only one way out - disassembling the engine, cleaning it from dirt and replenishing the lubrication.
As we can see, there are two ways to get rid of the creaking: either eliminate the mutual movement of tightly pressed parts, or lubricate the rubbing parts.