Valve burned: signs and causes of malfunction

As you know, the engine uses a lot of complex systems. One of these is the gas distribution mechanism. Now many people are discussing the problems of a broken belt or a weakened chain. But few people mention such an element as a valve. It is this part that is responsible for the intake of the combustible mixture and the exhaust of the exhaust gases. One of the typical malfunctions is a burnout. What are the signs of a burnt out valve? About this - later in our article.

Why is this happening?

This fault occurs for various reasons. And from the burnout of the valve, even the owners of new cars are not insured. Also a similar problem exists on diesel engines. What are the signs of a burnt out valve on the VAZ-2110? Usually, the culprit is the clamped saddles. All this will be accompanied by a characteristic "tractor" rumble of the engine. The valve clearances must be in accordance with the norm. If it is not, there is a risk of a valve burnout. A similar problem can happen on modern engines. The fault of this is the non-working hydraulic compensators. If the oil does not pass through them, the gap will be set incorrectly. Among other signs, it is worth noting the incorrectly configured HBO (if installed on the car). When driving on a too lean mixture, there is a risk of burnout of one or more valves.

Than it is dangerous?

The consequences can also vary significantly, starting from the banal over-expenditure of fuel and ending with burn-out of the saddles. In more serious cases, damage to the piston and head occurs. How does this happen? A burnt out exhaust valve, the symptoms of which will be considered further, is broken up into small pieces. As a result, a part of the "plate" falls into the combustion chamber. So there are badasses and other damage. Long-term operation of such a car can lead to a complete replacement of the motor.

Signs of a burned-out valve

On VAZ-2110 and other cars this malfunction will be accompanied by engine throttling. You will feel like one of the cylinders has stopped working. Also, the thrust will significantly decrease, the fuel consumption will increase. What to do in this case? If the valve is burnt out, the signs of malfunction will be accompanied by low compression. The chamber will not produce the right pressure for pushing the piston. Therefore, first we take the compressometer in hand, twist the candles and insert them into each cylinder one at a time. It is worth noting that the indications of compression are very different on diesel and gasoline engines. In the first case, this parameter is at the level of 23-27, in the second - 10-12. But there are exceptions. For example, on de-engineered engines (the old Soviet production, which is designed for the 72nd gasoline), this figure is 6-7 points.

It is worth noting that low compression can cause a worn-out cylinder-piston group. In this case, the valve will be in normal, working condition. But how can you be sure of the accuracy of the measurements? To do this, experts recommend pour a little oil into the cylinder through the candle well. Use a medical syringe. It is important that the oil corresponds to the parameters of the factory (or that was previously filled).

After that, install the compressometer and call the assistant, so that he scrolls the starter on your team. The essence of the method is very simple - oil due to its viscosity will close the cavities in the walls of the cylinders. So we exclude the case with worn rings. If the oil reading is below normal, then the valve is burnt out. The signs are visible.

Candle testing

If you do not have the right oil or syringe at hand, you can determine the malfunction by the nature of the wear of the candles. To do this, they should be unscrewed from the seat and carefully inspect the condition. The candle will be dry, without oil coating. Also air will emerge from the engine breather or smoke of a blue color. If this is a relatively new engine and the signs of a burned valve have been confirmed, then most likely you have rings.

How to avoid a problem?

The main cause of burnout is the work of the part in the mode of increased loads. The operating temperature of the valve is about 600-650 degrees. To prevent overheating, the gaps should be checked. Because of the short distance, friction occurs and, as a consequence, the valve overheats. Symptoms can also indicate low-quality fuel. On carburettor cars, the mixture is adjusted manually. It is important not to allow too poor a mixture. The same goes for cars with HBO. There are two main generations:

• The second.
• Fourth.

In the first case, the mixture is adjusted mechanically, by adjusting the "greed" tap. Adjust it is very simple - we turn the tap until the machine starts to stall. Then unscrew it for 1-2 turns. This is the most optimal setting. In the case of HBO of the fourth generation, the adjustment is done programmatically by specialists. If the valve has burnt out, pay attention to the quality of the product when buying. A defective element will not last long. A qualitative valve eliminates various risks, scuffs and other flaws. The very detail is inexpensive, but with the installation will have pretty sweat. After all, for replacement, you must "throw off" the head of the block and make further grinding of the saddles.

Conclusion

So, we found out why the valve burns out. The signs basically come down to the rope - one of the cylinders will not work properly, as the mixture immediately evaporates outward. To prevent a second burnout, you should properly adjust the carburetor or HBO, as well as monitor the valve clearances. If there is a characteristic noise, it means that the clearance is incorrect or the hydraulic compensators were clogged.