What is the clutch of the car?
The clutch is one of the most important parts of the car. Its task is to connect the flywheel to the crankshaft. Therefore, it acts as a separator between the engine and the wheels.
In this way the engine can stay on and turn even when the car is stationary.
In fact, the clutch is not a single component, but the disc, the pressure plate and the pressure plate bearing.
The most characteristic part, the disc, is covered on both sides by a friction material.
When we press the clutch pedal, we lift the pressure plate, which, when the clutch is released, releases the movement of the engine from that of the wheels.
By temporarily separating the two discs we obtain a smoother gear change without "jerking".
Burnt clutch: What does that mean?
By "burnt clutch" we refer to the problem that the abrasive material on both sides of the clutch disc is excessively worn.
When this material wears quickly, it creates the unpleasant smell of burnt plastic, hence the term "burnt clutch".
This pungent and intense odor can be noticed even after a poorly executed gear change. Another condition that causes this unpleasant smell is overheating of the clutch uphill.
If the smell is noticed when the engine is switched off, then the clutch is completely burnt out and the clutch components need to be replaced.
Why is the clutch of the car burnt out?
As explained above, the clutch in the car consists of a disc that is normally pressed between the flywheel and the crankshaft.
In doing so, the disc forces the other two components to move in unison and this ensures the transmission of power from the engine to the wheels.
As long as the disc is kept firmly depressed or completely detached (during gear changes) wear remains controlled.
If, on the other hand, we have the bad habit of "scraping" the clutch or keeping our foot on the clutch pedal while driving, the wear increases enormously.
This is because in both cases the clutch disc stays up long enough to wear the abrasive material very quickly. The abrasive material becomes almost like sandpaper, which wears down the other components over time.
When the abrasive layer wears away quickly or has reached the minimum limit, you start to get that pungent smell, called "burnt friction stench".
1st symptom of a burnt clutch: the clutch pedal is too soft.
At the end of the day the clutch is an iron disc on which several steel springs are pushed.
Lifting the clutch and disengaging the transmission should then require a certain amount of force when depressing the pedal.
In practice it should feel like you're crushing a metal machine, not as hard as the brake pedal, but down.
If you don't feel any mechanical resistance when you press down on your car's clutch pedal or it feels like you're stepping on a cushion, then there's a problem.
This is a clear indicator that our car's clutch is almost completely worn out and we need to get it replaced.
A soft clutch pedal is one of the easiest symptoms to notice and therefore should not be ignored.
2nd symptom of a burnt clutch: difficulty in engaging reverse gear
When we engage reverse we force the crankshaft to transmit power in the opposite direction it was designed for.
Nothing dangerous or impossible, however, engaging the reverse gear should require a little more force and pressure than engaging the other gears.
It's no coincidence that when you engage reverse gear you often hear a loud clanking noise or, in the case of some vehicles, a vibration throughout the car.
Putting the car into reverse is one of the most difficult tasks for the drive shaft and requires a lot of force, especially from the clutch.
For this reason, when the clutch is burnt out or almost completely worn out, it can be difficult to "find reverse" and engage it.
Failure to engage reverse gear is therefore a clear sign of a burnt clutch.
3rd symptom of burnt clutch: clutch slipping
Another clear symptom of burnt friction is the feeling that the clutch slips or slides when pressed. In practice it does not seem to engage properly with the other mechanical components.
In practice, when the clutch pedal is depressed it does not engage properly or when the clutch pedal is released, it does not come out all the way.
This condition is called a "slipping clutch" because the gears seem to shift in a "buttery" manner and not firm and mechanical as usual.
In addition to the clutch pedal feeling soft (see symptom 1) you will notice an increase in engine rpm without an apparent increase in power. In other words, the engine revs increase but the speed of the car does not increase, as if you were in neutral.
If the clutch slips, you will notice it especially when driving uphill or on the motorway. Try to change gear, step on the accelerator but instead of power you get a clunking noise from the engine. Not good!
For those less familiar with the car who can't tell if the clutch is slipping, there is a very simple test. Start the car, shift immediately from neutral to 3rd or 4th gear and pump some gas. If the car locks up and shuts off (like when you first learned to drive) the clutch is fine. If, on the other hand, you start to hear that clunking noise and the engine revs increase, you have a completely burnt clutch. Time to go to the mechanic!
So far we've looked at some symptoms related to the car's performance. In fact, a burnt clutch also sends us much more subtle and implicit signals.
One of these symptoms, perhaps the clearest, is the smell of burnt plastic or metal. This is a strong pungent odor that will hardly go unnoticed even by the least experienced. As explained above, it can be related to a sluggish gear change. But if it remains present even with the engine off, the clutch is definitely gone.
5th symptom of burnt clutch: clutch pedal vibrations
In addition to the clutch pedal being too soft, our foot can perceive other symptoms of a burnt or end-of-life clutch.
If while driving we rest our foot gently on the clutch, preferably without wearing military boots or rubber soles, and we feel a vibration, then there is a problem.
In this case, the clutch has practically reached its death and, being worn out, cannot decisively lock the flywheel and crankshaft.
6th symptom of a burnt clutch: difficulty in changing gears
Think about it, the sole purpose of the clutch is to make it easier to shift gears without having to completely lock up the engine.
If it starts to struggle to do its sole job, then it's probably time to change it.
This symptom is easily recognizable if we have difficulty shifting gears while pressing the clutch pedal all the way down.
Simply put, if you feel like you need more room for the clutch pedal, it's time to find a good mechanic. Simple!
7th Symptom of burnt friction: metallic rubbing sound.
In addition to our foot, we can also use our ears to see if the clutch is gone or burned out.
If we hear a metallic grinding noise as we engage the gears, as if we're dragging irons on the tarmac, then the clutch is probably gone.
In this case, however, the problem could be related to overly worn bearings (which are much cheaper to replace than the clutch kit assembly). Understanding where the problem lies is not easy and makes us understand even more the importance of a good mechanic.
Chances are you have no idea what car bearings are. That's why we've written another article in which we describe what car bearings are and how much it costs to replace them.
What is the smell of burning friction?
The smell of burnt friction is often identified as a "metallic" or "burnt plastic" smell.
What is actually perceived by our nose is the smell emitted by the abrasive paste on the clutch disc when it overheats.
This overheating occurs when, by not inserting the clutch firmly and smoothly, the disc rubs against the flywheel and pressure pad for a few seconds.
What are the symptoms of a worn friction?
When we speak of a worn clutch we are referring to a condition very similar to a burnt clutch. The symptoms of a worn clutch are, in fact, almost identical to those of a burnt clutch.
The biggest factor in clutch wear is driving style. Bad habits such as leaving your foot on the clutch pedal while driving or shifting gears abruptly are crucial to the life of the clutch.
Therefore, a good "driving awareness check" is helpful in determining whether your clutch is being used correctly or in a way that is detrimental to its life.
A worn clutch will then show the same symptoms as a burnt clutch.
Why is it important to replace a burnt or worn clutch immediately?
Continuing to drive with a burnt or worn clutch will not only cause additional wear and tear on your car's components, but could become a safety hazard.
Failing to shift gears effectively can become a source of distracted driving or make the car uncontrollable - not good!
What to do with a burnt clutch?
If you realize you have a burnt clutch, the only option is to go to a mechanic and ask for a clutch replacement.to prevent further damage and ensure the driveability of the car.
Once removed from the car, the mechanic will be able to diagnose what the problem is and decide which components need to be replaced. However, in a clutch replacement operation the cost of replacement parts has very little effect. What drives the price up is the amount of man hours needed to get to the clutch. In fact, it is a component located inside the car that is difficult to reach without disassembling many parts.
When replacing the clutch, we at Pistonudos always recommend replacing all the components (disc, pressure plate and pressure plate bearings) to avoid having to reopen everything in the future to replace a new defective part. It is better to deal with a clutch that has worn out once than to have to touch it again later.