What could be more disturbing than noises when you start your car… Indeed, you maybe already noticed noises when you start your Mercedes Classe Cls and generally it’s frustrating. It might not be anything serious, but each new engine starts usually turns into a scary moment during which you don’t know if your engine will start. That is why our team has decided to produce this document to help you find its source. To do this, first, we will see the case of noise when starting on Mercedes Classe Cls but the car does not start, and finally, the noise you can experience on your car if it starts, first cold and then hot.
I listen to a noise when I try to start my Mercedes Classe Cls, but the engine doesn’t start
I find a clicking noise at the start of my Mercedes Classe Cls
If you listen to a noise when you want to start your car, and it does not want to turn on, it is very likely that it is the battery that is triggering the problem. Indeed, if you hear clicking noise when you start your Mercedes Classe Cls, and it sounds like a ticking, you almost certainly lack the energy to run your starter, check your battery with a voltmeter and swap it if required. In case that after looking at your battery, you still know a noise when starting your Mercedes Classe Cls and it does not want to start, refer to this article about starter motor noises on Mercedes Classe Cls for more info and to find the source of your problem.
I perceive a noise when I start my Mercedes Classe Cls but the engine it starts
I listen to a noise when I start my Mercedes Classe Cls
- Grinding or squealing type noises when I start cold Mercedes Classe Cls :
If you listen to a noise when you start your Mercedes Classe Cls, and this noise looks like grinding or squealing noise, which can also be relating to vibrations, it is possible that it is the combustion of your car that is involved. Indeed if you have an air/fuel mixture that is not good the normal general performance of the engine will be altered. Verify the state of your injectors and air intake system. For more info on the origins of injection-related noises on Mercedes Classe Cls, see this article. - Cold start friction parts Mercedes Classe Cls :
If you know cold friction noises on Mercedes Classe Cls, it is almost certain that they come from one of your belts. Either the serpentine belt starts to wear out and therefore triggers a friction noise. It is also possible that the tensioner roller or damper pulley is worn out and that as a result the extension belt triggers a friction noise, often when cold. Visually examine your belt and swap it if required. If you have other friction noises, and it doesn’t come from your serpentine belt, we have a full article on engine of your Mercedes Classe Cls.
I listen to a noise when starting my Mercedes Classe Cls even when hot
- rubber mount / silent bloc dead motor
If you listen to a clacking noise just as you start your car’s engine and it is more than 100,000 km long, it is possible that some of your engine silentblocks or rubber mounts are good to be swapped. And the huge vibrations produced by starting the engine can make starting noise on Mercedes Classe Cls. Verify their state and swap them if required. Consult this article if you would like to have detailed info on rubber mount noises on Mercedes Classe Cls. - Motor flywheel
Finally, if you experience a noise that sounds a little like a crank noise when you start your Mercedes Classe Cls, even when hot, it is possible that if your series is equipped with a dual-mass flywheel, it is the source of your trouble. Indeed, these parts have created a lot of trouble on many cars. When they take part in the game they make noise when you start your Mercedes Classe Cls and when you turn off the engine. Have his state examined by a mecanist.
