What causes redness in the engine exhaust pipe?

The reason why the exhaust pipe turns red is that the engine is not powered enough, the intake pipe is tempered, and the exhaust pipe is burned red after a test run.

Fault analysis: to eliminate any type of fault of the engine, first grasp the appearance characteristics of the fault, then analyze the essence of the external features, and finally analyze the main reason for this phenomenon according to the principle of the engine, and then check and eliminate it in combination with the structure of the engine. According to the working principle of the engine, the only reason why the exhaust pipe is burned red is that the mixture in the cylinder burns in the exhaust pipe, heating the exhaust pipe to a scorching state.

Therefore, in order to troubleshoot this fault, the first step is to analyze the conditions under which the mixture will enter the exhaust pipe.

From the working process of the four-stroke gasoline engine, it is not difficult to know that the main reasons why the combustible gas that is burning in the cylinder enters the exhaust pipe without burning is finished

1) Mixed gas dilution. The mixture is too dilute and will cause the mixture to burn slowly in the power stroke, so that it is still burning in the exhaust stroke, and the combustion gas enters the exhaust pipe and burns the exhaust pipe red.

2) The ignition time is too late. Ignition will cause combustible mixture to burn in the condition that the exhaust valve has been opened, still burning, make the combustible gas that is burning rush into the exhaust pipe through the exhaust valve, continue to burn in the exhaust pipe, and the exhaust pipe is heated and red.

3) The exhaust valve is not closed tightly. If the exhaust valve is not closed tightly, the gas burned in the power stroke leaks from the exhaust valve that is not tightly sealed to the exhaust pipe, and the exhaust pipe is heated and burned red, and the valve will be burned out in serious cases.

4) The electronic control system is out of balance, resulting in the air-fuel ratio of the mixture, which makes the mixture too thin.

The reasons for the redness of the engine exhaust pipe are: 1. Part of the gas in the cylinder enters the exhaust pipe and continues to burn; 2. The mixture is too thin, but the combustion rate of the fuel gas is slow after ignition, and it is delayed until the exhaust stroke is still burning; 3. The burning gas rushes into the exhaust pipe, which increases the exhaust temperature; 4. The exhaust valve is not tightly sealed or the valve clearance is too small, which causes the combustion gas to be discharged into the exhaust pipe and the temperature of the exhaust pipe increases; 5. The injection time is too late. Workaround:

1. The concentration of the mixture should be adjusted; 2. Check and adjust the valve clearance; 3. Adjust the ignition or fuel injection time.

1.Lack of cylinders. There are cylinders that do not work, causing the unburned gasoline in the cylinder to enter the exhaust pipe and burn.

2.The gas distribution phase and ignition timing are incorrect. It will also cause incomplete combustion of gasoline to enter the exhaust pipe and continue to burn, resulting in unstable idling, difficult starting, insufficient power and other faults.

3.The injector is over-injected, and the injector needs to be replaced, the turbocharger replaced, and the valve re-wracked.

4.When the car is under heavy load, long-term high-speed driving or the slope is large and long, the throttle valve has been in the position of full open or nearly fully open, the exhaust temperature is high, the gear is only in the first or second gear, the speed is low, the windward is small, and the cooling is poor.

5.The exhaust valve clearance is too large, causing the exhaust valve to open too late.

6.The valve springs are too soft, so that the exhaust valve opens and closes late, which not only makes the intake branch pipe "discharge", but also affects the temperature of the exhaust pipe.

7.The ignition time is too late, and when the exhaust valve is opened, some of the stick gas is burning, so the exhaust pipe temperature is very high.

8.There is too much carbon accumulation in the exhaust pipe and muffler, and the heat cannot be transmitted, causing the exhaust pipe to burn red.

The main reasons why the exhaust pipe burns red when driving are:

The burning gas rushes into the exhaust pipe, increasing the exhaust temperature;

The exhaust valve is not tightly sealed, or the valve clearance is too small, resulting in combustion gas being discharged into the exhaust pipe, which increases the exhaust temperature; The late injection time not only causes the combustion speed to be slow, but also makes the combustion incomplete, causing the diesel fuel to burn in the exhaust pipe in the later stage of fuel injection, so that the exhaust temperature increases.

During maintenance, the mixture concentration should be adjusted, the valve clearance should be checked and adjusted, and the ignition or fuel injection time should be adjusted.

Remove the exhaust pipe and muffler, extract the muffler and decompose, put it in kerosene (or chemical) to remove the carbon deposit, or scrape off the carbon deposit with a shovel, or put it on an open flame to burn the muffler core, and finally clean it with a wire brush. Replace abrasive and damaged parts if necessary and repair them.

Normal state. The temperature of the exhaust pipe of the engine in normal operation will not be very high, and the exhaust pipe will only burn red if the engine works for a long time under heavy load.

In addition, the common reasons for the redness of the exhaust pipe are: the valve clearance is too large or the valve spring is too soft, so that the valve opens too late; The angle of early opening and late closing of the valve is not suitable; Ignition time is too late and there is too much carbon accumulation in the exhaust pipe and muffler.

Only 5j can occur this situation when the load is under ding. Under normal circumstances, the redness of the exhaust pipe is B too large in the gas clearance or the valve spring is too soft, resulting in the juice of the valve starting too late, and at the same time, the angle of the valve opening early and closing late is not suitable, and the exhaust pipe redness will also occur. In addition, the ignition is too late, or the carbon deposit in the exhaust pipe and muffler is too much, which will also cause the exhaust pipe to hair.

Red. If this fault is acceptable, you should first check whether the valve clearance is appropriate and whether the valve is not closed tightly. If it is a diesel engine, it is also necessary to check whether its fuel injection time is appropriate.

When the injection time is too late, the connection between the fuel injection strip drive device and the fuel injection pump can be disconnected, the engine crankshaft can be rotated in the opposite direction, so that the stop mark of the first cylinder is aligned, and then the fuel injection pump drive plate and the fuel injection pump adapter plate are connected. If it is a gasoline engine, it is also necessary to check the ignition time of the distributor distributor and whether the mixture is too thin. When the mixture is too thin, it is necessary to check whether the oil lang of the float is too low, and whether the oil channels of each nozzle of the carburetor are unblocked, and it should be adjusted and cleaned when necessary.

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The exhaust pipe is to discharge the exhaust gas in the engine, the engine is full of high-temperature parts, and the exhaust gas is also very high, so the exhaust pipe will be very hot, if the exhaust pipe is burned red, there may be something wrong with the exhaust device. If it is completely red, it is a three-way catalytic blockage. Caused by poor exhaust air.

··· The reason for the redness is that the exhaust pipe is clogged, check the three-way catalytic section.

What causes the engine exhaust pipe to burn red? Indicates that the engine burns badly. It is necessary to start with combustion and three-way catalytic emissions, and if the three-way catalysis is not damaged, it can be passed by directly lifting the combustion.

There are 1 cleaning three-way catalysis 2Clean the oxygen sensor 3Directly improve fuel quality4To clean the oil circuit, use Add 5Find someone to check on behalf of 6High-efficiency and alkaline cleaners to clean the combustion chamber – not recommended and can damage the piston rings and oil seals.

To clean the oil circuit, the company has a general idle shake fuel additive fuel additive cleaning two-way curing agent can prevent and remove carbon deposits in the oil circuit, prevent car shaking, and prevent abnormal car exhaust.

Based on past experience, the preliminary diagnosis was that the three-way catalytic reactor was damaged, and its collapse hindered the flow of exhaust gases, resulting in a serious decline in the heat dissipation performance of the engine. Slight engine shake may also be caused by this. So, I took it down for inspection, and found that it was damaged, and I thought it was probably doing something wrong.

However, when the new parts are replaced and the exhaust pipe is not abnormal, the retest car is installed, and the fault is still the same.

As we all know, the oxygen sensor is based on the amount of oxygen in the exhaust gas to give a feedback message to the computer. If the mixture is too thick or too thin, the voltage will vary higher or lower. The engine computer will continuously adjust the fuel injection condition according to this changing signal, which is a closed-loop control process, which can control the air-fuel ratio in a relatively ideal state.

When the oxygen sensor is damaged, the mixture loses its regulating function, which may cause the mixture to be too thick, so that part of the mixture is not fully combusted, and continues to burn after being discharged into the exhaust pipe, thus burning red. Then the exhaust gas analyzer was used to detect the exhaust emissions, and it was found that the mixture was too thick. For this reason, the oxygen sensor was checked and measured with a high-impedance multimeter, and its wiring was normal, but the adjustment function was not obvious after landing, and it was judged that it was damaged, so it was replaced.

However, the results were still not satisfactory, the exhaust pipe was also red, and the exhaust gas analyzer showed that the mixture was still too thick. In this way, the fault is not with the oxygen sensor, nor with the exhaust pipe.

Calm down and analyze carefully, it is none other than the following reasons:

l) The oxygen sensor is not working well, resulting in the mixture being too concentrated, so that the mixture burns in the exhaust pipe.

2) The three-way catalytic converter is damaged, or the exhaust pipe is blocked, resulting in poor circulation, so that the high temperature discharged cannot be quickly dissipated.

3) The ignition system is faulty, and the ignition of one or several cylinders may not be normal.

4) Oil circuit failure, may be a cylinder or several cylinders of poor oil injection atomization, or long-term fuel injection.

In this case, the circuit was checked first, and after careful inspection, it was found that all sensors were normal. No fault code was found to be detected by the fault diagnosticator. Check that the resistance value of the cylinder line is within the specified range, and the low-voltage line is also normal, but the spark plug electrode has a partial burning phenomenon, which is also a reason for the unstable operation of the engine for the EFI vehicle.

Originally, it was a fire jump through the gap between the two faces, but now it is only a breakdown and a fire jump between the two lines, and the ignition energy is obviously insufficient. As a result, the ignition is poor, the combustion is not sufficient, and a large amount of mixed gas enters the exhaust pipe for combustion. Therefore, the spark plug was replaced, the gap was adjusted, and the cylinder line was inserted into the in-situ test, but the fault remained the same, and the cylinder breaking test was done, and the effect was not obvious.

The main reasons for the redness of the diesel engine exhaust pipe are: 1. Air filter.

Blockage: insufficient air intake, poor combustion; 2. The amount of fuel injected is too large: the combustion is incomplete to the exhaust pipe is still burning; 3. Late oil supply time

Combustion lags until the exhaust pipe is still burning; 4. Poor atomization of fuel injector: combustion is not completely burned in the exhaust pipe. Here are some other things to introduce Youqing:

1. Introduction: The diesel engine is an internal combustion engine that uses diesel fuel as a fuel. Diesel engines belong to compression-ignition engines.

2. Principle: When the diesel engine is working, the air in the cylinder of the diesel engine is compressed to a high degree due to the movement of the piston, reaching a high temperature of 500-700. Then the oil is sprayed into the high-temperature air in the form of a mist, mixed with the high-temperature air to form a combustible mixture, which automatically ignites and burns.

The energy released during combustion acts on the top surface of the piston to push the piston through the connecting rod and crankshaft.

Mechanical work that is converted into rotation.

The reasons for the redness of the engine exhaust pipe are: 1. Part of the gas in the cylinder enters the exhaust pipe and continues to burn; 2. The mixture is too thin, but the combustion rate of the fuel gas is slow after ignition, and it is delayed until the exhaust stroke is still burning; 3. The burning gas rushes into the exhaust pipe, which increases the exhaust temperature; 4. The exhaust valve is not tightly sealed or the valve clearance is too small, which causes the combustion gas to be discharged into the exhaust pipe and the temperature of the exhaust pipe increases; 5. The injection time is too late. , Extended Content:

The maintenance methods of the exhaust pipe are: 1. Avoid long-term high-speed driving in the state of closing the choke door; 2. Avoid installing wind shields or decorative items in front of the engine and muffler; 3. Reduce the throttle at high speed in situ for a long time.