The maintenance case we shared this time was a normal one that couldn't be operated when the disease was caused and was towed by the trailer to the Audi A5. After picking up the car, the owner told us that, a few days ago, it was found that the engine fault light on the instrument panel was on. At the same time, the engine was slightly shaken. The owner did not take it seriously and thought that it might be a bad oil product. The problem alarm, and then drive for some time, the fault light may disappear on their own. After driving about 100 kilometers one after another, it was found that the engine became more and more jittery. After the owner stopped and called the trailer directly, the car was sent to our shop for inspection. Troubleshooting Using Audi's special diagnostic instrument to detect the engine's electronic control unit, it was found that there was a cylinder misfire fault code. According to our experience, the possible causes of the fault usually have the following reasons: 1, ignition system failure (ignition coil, spark plug, etc.); 2. Injector fault (The mixture of injectors is attenuated and the mixture of injectors is leaky and the injectors are leaking to cause excessive mixing of vapors); 3, mechanical failure (engine intake valve is not closed, the engine exhaust valve is not closed, the gap between the piston and the cylinder wall is too large, etc., caused by the lack of pressure in the cylinder, etc.); Based on the above-mentioned possible causes of the failure, we first detected the ignition coil and the spark plug of the ignition system, and checked the ignition coil with a replacement method, and found that the ignition coil of the original car was working properly. Considering that the A5's mileage has already reached 40,000 kilometers, and the spark plug has exceeded the replacement cycle, it has not been replaced. We will focus on checking the spark plug. Spark plugs have not been found to be completely aged and damaged. However, the old spark plug of the first cylinder had traces of flooding, and a lot of fuel was accumulated on the electrode. Looking at the first cylinder, the residual fuel in the cylinder could be clearly seen, which made us believe that the injector nozzle fault was more suspicion. After opening the fuel injector and checking it, it was found that there was a lot of fuel residue in the head of the injector corresponding to the first cylinder, and the injectors of the other three cylinders were normal. Obviously, this injector has been damaged, unable to control the amount of fuel injected, leaking a lot of fuel, and remaining in the first cylinder, so that the first cylinder can not work properly causing jitter. The reason for the oil leakage of the fuel injection nozzle is presumed to be that the fuel injection nozzle is dirty or that the fuel injector is excessively worn due to the use of poor quality gasoline for a long time, and the fuel injector has impurities, which results in the fuel injection nozzle not closing tightly and causing poor atomization. So, we replaced the new nozzle for the A5. After checking on the car again, a new problem has come. The first cylinder still cannot work normally and it is still reported as a fire failure. Checking with a cylinder pressure gauge, it was found that the pressure in one cylinder was almost completely absent. Is there a gap between the piston and the cylinder wall? We judge that because of the failure of the fuel injector and poor atomization, the piston is working abnormally, and then it is forced to continue driving, causing damage to both the piston ring and the cylinder wall. After soliciting the owner's consent, we overhauled the engine and repaired the lesions and maintenance. This overhaul includes auxiliary oil, camshaft components, timing components, pistons, generator belt components, and various sealing gaskets. After the completion of the first cylinder A5 fire failure completely cured. Through this case we also remind riders: - The engine fault light should not be neglected. It needs to be investigated in a timely manner. At this time, the service provider can be required to bring the detection computer to the door. Once the problem is found, the trailer is to the service provider. - When the fault light comes on, if there is an abnormal condition such as engine shake (even slight jitter), stop immediately. Indeed, the engine fault light alarm, there are many situations that do not affect short-distance running (such as mixed gas concentration alarm, slight vacuum pressure, etc.), but with the jitter, abnormal noise must be immediately stopped, in this case if the owner at the time of parking The call service provider only needs to replace the fuel injector with a value of more than 1,000 yuan. However, it ignores the continuation of driving, and the engine piston seal ring is damaged. Overhaul costs thousands of yuan, which is not worth the candle.
Cold mill work rolls
Description: Work
rolls for cold strip mill, forged steel working roll performs as a tool to
transform materials under normal room temperature, it is the most wear and tear
spare parts during the rolling process. By using 2%Cr, 3%Cr, 5%Cr materials
series, we have greatly improved our products both in terms of quality and
diversification to meet customers different requirements.
Material: Forged steel,
Chromium 2% , Chromium 3%, Chromium 5% or as per the customer`s requirement.
Barrel Diameter: 1500mm
maximum
Unit weight: 25mt/pc
Type: Single rolls,
forging.
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