The engine will shake, and so will cylinders 3, 4, 6 and 12.

However, the inherent defects of the 3-cylinder machine will make the jitter more obvious, and the manufacturers have no choice but to develop some technologies to alleviate this jitter.

3-cylinder engine jitter is a natural defect and cannot be avoided.

First of all, we should know that the commonly used four-stroke engine is composed of four steps: intake hiss, compression, power bang and exhaust.

A 4-cylinder engine can correspond to one step per cylinder. After one cylinder has finished its work, it will be connected to the next cylinder. So, the turn is smooth.

If you are an engine larger than 4 cylinders, it involves the "power stroke superposition effect", so we won't go into details.

The 3-cylinder machine is one less than the 4-cylinder machine. Don't underestimate this. It will cause the cylinder gap to become larger, the power will be interrupted, and the natural jitter will be greater.

Here's the thing: it turns out that four hamsters take turns to generate electricity for the light bulb, and the light bulb can be on all the time, and then one hamster is exhausted, so between each hamster, the light will wait for a while and the light will go out for a while.

This is what will happen. It won't last long.

There is a paper in the magazine Automotive Practical Technology, which mentioned the analysis and research on reciprocating piston engine jitter of automobile three cylinders.

Because the cylinder layout of a three-cylinder engine is not highly symmetrical, there is always one cylinder doing work alone, such as: 2 up, 1 down, or ... right? Or vice versa.

The moment of inertia it produces can't be offset, so the whole thing is shaking.

In order to prevent cylinder 3 from shaking, the manufacturer developed "black technology"

Although this jitter is inevitable, there are still ways to alleviate it.

In the environment of increasingly strict emission requirements in various countries, major manufacturers have also thought of many ways to solve the problem of 3-cylinder machine jitter, as well as some "black technology".

Most 3-cylinder machines use balance shafts and suspension systems to reduce jitter.

Most 3-cylinder engines, such as BMW B-series 3-cylinder engines, will reduce the jitter by increasing the balance shaft and optimizing the engine mounting system.

There is a paper in the journal of small internal combustion engine and vehicle technology, which mentioned the balance analysis and balance shaft design of engine crank-connecting rod mechanism.

First-order and second-order reciprocating inertial forces are generated in the process of cylinder movement. If they are unbalanced, the vibration will be transmitted to the car body through the engine.

On the one hand, it affects comfort. On the other hand, it may affect the life of parts. The balance shaft is used to counteract these vibrations.

Like a top. If it is heavy and light at the same time, it will turn me, me, and I will stop for a while.

You break both sides into the same weight, and "Meow Meow" can turn for a long time, right? Friends who have played gyro know, right?

Another widely used method is to optimize the engine mounting system. In the vernacular, the engine is in the car, right?

The journal articles "Rubber Industry" and "Research Progress on Fatigue Life of Engine Rubber Mount" mentioned above.

Engine mounting system is an elastic connection system between engine powertrain and frame, and its design directly affects the transmission of engine vibration to the body.

Generally speaking, the manufacturer will optimize by changing the material of the machine foot pad or switching to the hydraulic suspension system.

For example, Buick's GL6 uses a hydraulic mounting system. It was shaking, but it didn't touch the car. We can't feel it, so it doesn't shake, right?

Manufacturers have also developed many "black technologies"

However, to reduce vibration, it is not enough to balance the shaft and replace the machine pad. Some manufacturers have also come up with some so-called "black technologies" to solve these problems.

Ford 1.0T EcoBoost engine, because of the pricing, the 3-cylinder model is terrible, and the sales volume is not good at all, but it is undeniable that this engine is ok.

During the eight years from 20 12 to 20 19, this engine won the title of "Best Engine" in seven international engine awards.

The only defeat was in 20 18, and it was won by Volkswagen's 1.0L TSI inline 3-cylinder turbine engine by a narrow margin of 16.

In addition, this three-cylinder engine was selected as "Ward's Top Ten Engines" twice in 14 and 15, and it did win the prize, but it still could not be sold.

The selection of these awards is not only to see what skills you have, but also to conduct an actual road test and conduct a comprehensive evaluation of the engine, fuel consumption and NVH.

Ford's engine has won the title of "Best Engine" for many times in a row, at least in the eyes of many experts, and its ride comfort is handled fairly well.

There is no balance shaft, and the purpose of vibration reduction is achieved by adjusting the internal structure of the engine.

It's like: in the past, mobile phones needed buttons, "click, click, click", right? Now all the key functions are directly installed on the screen, and the touch screen is gone.

Ford once introduced this engine at an exhibition in Los Angeles and said, "We didn't use a balance shaft."

What's going on here? The imbalance between flywheel and pulley can reduce some unfavorable factors brought by engine structure.

Like a seesaw: two people sit on each side, the left side is heavy and the right side is light. Originally, I added two bricks to the right to balance it.

But I just choose to make the right side of the seesaw heavier or longer. Isn't that that the two sides are still balanced?

What should I do if the 3-cylinder car shakes after I buy it back?

What I said earlier is the manufacturer's handling method. The owner of a three-cylinder car said, "I bought a three-cylinder car myself and shook it when I needed it." What should I do? "

As a car owner, there is no good solution to the later jitter. The repair shop should check whether the wearing parts have been replaced and whether there is any looseness.

For example, as we said before, the machine pad used to be very elastic and soft, and the engine shook and the car did not shake. After shaking for a long time, the rubber broke You can also solve this problem by substitution.

Generally, the master will say "about 5 to 8 years, once every 6 years." It is probably such a reference range, and it is deceptive to change it in two years.

In addition, there are many other factors that may also cause jitter, such as tire imbalance, nozzle blockage and so on.

But in fact, no matter how many cylinders are driven for a long time, these problems may occur. This is not the pot of a three-cylinder car.

Therefore, for friends with obvious jitter and little experience in the later period, you can go directly to the repair shop or 4S shop to have a look. This is the simplest or most effective method.