Throttle housing

Continue yesterday's maintenance? Pentium B50 engine flameout, serious vibration. After the master replaced the fuse and spark plug, the engine operated normally. However, the idle speed of the engine is still unstable, and there is abnormal sound when stepping on the brakes during trial operation. What's the problem?

For the problem of unstable engine idle speed, the master first thought of the throttle. It was particularly dirty when the intake pipe was removed, and it was basically determined that the throttle was too dirty. For the problem of abnormal sound when stepping on the brakes, look at the front wheel brake pads with electric lights, which basically reaches the wear limit, and check that the rear wheel brake pads are still very thick.

According to the detected problems, the maintenance suggestions given by the master are: clean the throttle and replace the front wheel brake pads. This is the direct cause of the problem, and the owner naturally agrees to repair it. Look at the picture below. This is the vehicle nameplate located in the engine compartment, and you can see the basic information of the vehicle.

As shown below, this is the front state of the throttle valve after the intake pipe is removed, which is really dirty. The master said that these impurities are sludge formed by oil and gas mixed with external dust.

Where did these oil vapors come from? Is this the price? Let's look at the picture below. This is the state before the master removed the intake valve. There is also a small tube next to the intake pipe, which is the small tube shown by the orange arrow with an electromagnetic valve on it. The plug has been pulled out and connected to the lower part of the oil cover, as shown by the green arrow.

The function of this small tube is to let the oil and gas inside the engine enter the coarse intake pipe. This pipe is not always straight, but is controlled by the solenoid valve (controlled by the engine computer) shown by the orange arrow.

After passing through this small tube, oil and gas enter the engine combustion chamber through the throttle valve for combustion. Its purpose is not only to reduce air pollution caused by oil vapor, but also to maintain the pressure of engine lubrication chamber.

Let's take a look at the state of this intake pipe after it is removed. As shown in the figure below, this is the coarse intake pipe connecting the throttle. The inner wall of the pipeline is full of oil formed by oil vapor, and the lower part shown by the arrow is still accumulating oil.

As shown in the figure below, this is a small pipe cross connected with the oil cover, which is also filled with oil. As shown by the orange arrow, the pipeline is blocked and the solenoid valve is closed. ?

Seeing the residual oil at the air intake, I believe our motorists will understand why there is sludge at the throttle position. Because there are many pipes connected behind the throttle valve, it is more troublesome to completely remove it. So, after the master removed the fixing screw of the throttle valve, he put a piece of cloth under the throttle valve and began to clean it. As shown by the arrow below, this is the back of the throttle valve.

Let's look at the picture below. The master is cleaning the accelerator with a toothbrush and a special cleaning agent. At this time, the throttle looks clean.

While the master was cleaning the throttle valve, another master had removed the brake pads. As shown by the arrow in the figure below, the thickness of the brake pad is very thin when viewed from the side.

Let's look at the front of the brake pad. These two surfaces in contact with the brake disc should be smooth, but they are not smooth now. The master said that the bright front part of the brake pad is the part where the friction material of the brake pad is closely combined with the rear lining iron. At this time, the friction performance has been affected, and there will be abnormal noise. ?

As shown below, comparing the old and new brake pads, it can be clearly seen that the old brake pads are already very thin. The friction thickness of brake pads is closely related to the driver's driving habits. This Pentium has a mileage of 6,543,800 kilometers, and it is the first time to change the brake pads. Many car owners changed their brake pads less than 654.38+ 10,000 kilometers, which shows that this Pentium car owner has a good driving habit. ?

When the master cleans the throttle valve, matches it with the computer, and checks that there are no other fault codes, start the engine, and the idling operation is stable, and the oil filler door is normal. After replacing the brake pad, be sure to step on the brake first to make the brake pad fully contact with the brake disc. The subsequent driving test shows that the braking performance is normal and there is no abnormal noise.

This is the process of maintenance of Pentium B50 by master. Riders can simply understand, combined with the maintenance of the last article. I hope this maintenance case can help riders. For more car maintenance cases, welcome to pay attention to the "maintenance worker Xiao Wu" of WeChat official account.

This article comes from car home, the author of the car manufacturer, and does not represent car home's position.