Why do exhaust valves burn

If there is an issue with the valves, such as bent or burnt valves , it must be addressed immediately to prevent engine damage. What are the symptoms of a bad exhaust valve or bad intake valve? How much will it cost to repair bent or burnt valves? Keep reading to learn the answers to these questions and more. Intake and exhaust valves are the final component in the valve train system.

They are made of hardened metal that must withstand the extreme conditions of the combustion chamber. Intake and exhaust valves are responsible for controlling the flow of gases through the combustion chamber.

Intake valves let air in, whereas exhaust valves let air out. They are shaped to have a slim stem leading to a flatter face, with the intake valves often being larger than the exhaust. Each valve is designed to only move up and down, not side to side. When a valve is closed, it sits tightly on the valve seat to stop the flow of air. But when it is open, it separates from the valve seat to allow air to flow through. There are four events that must take place in an internal combustion engine to ensure operation.

These are called strokes. The first stroke is the intake stroke. The next stroke is the compression stroke. The next stroke is the power stroke. With the exhaust and intake valves remaining closed, the ignited mixture rapidly expands, forcing the piston back downward in the cylinder.

This in turn spins the crankshaft, which then through the power train eventually turns the wheels of the vehicle. The final stroke is the exhaust stroke. During the exhaust stroke, the piston will begin to head upward again, pushing the expended mixture through the now open exhaust valve. After the exhaust gases have escaped the cylinder, the exhaust valve will close and the intake stroke will occur again. Although valves can fail for a number of reasons, the two most common types of failures are bent valves and burnt valves.

Bent valves occur when the piston makes contact with the valves. This causes the valve to be no longer able to seal the cylinder correctly. Many engines are interference engines, meaning the piston travels upward beyond the lowest point that the valves travel downward during normal operation.

Cars are just like humans. Remember, how low we feel when we are sick. The same goes for the cars. When the entire exhaust valve is burnt, how can a car even start normally? Of course, it will, eventually, but then it will certainly show up some symptoms to let you know about the issues going on inside. A burnt valve does not allow the car to gas up, as it should. So, if you are having trouble starting the car, maybe you should check for the burnt exhaust valve.

When the cylinder in the engine fails to discharge appropriate amount of fire, it is termed as Misfiring. For the proper working of a cylinder, it is essential for these things to work appropriately, which are good compression, right spark at the right time, and a proper mixture of air and fuel. But when the exhaust valve is burnt, you can expect a proper compression, which is needed to avoid misfires. So, if the cylinders in the engine are misfiring, it is a clear sign of the exhaust valves being burnt.

Experts always suggest getting familiar with the symptoms to ensure that you detect the issues in the car before it turns into a bigger and unmanageable one. The burned exhaust valve issue is common, and anyone can face it any time. So, getting familiar with these symptoms will surely help you in understanding that the valve has burnt. The most common failure of valves is bending or breaking as a result of contact with the pistons.

If you suspect your engine may have bent or broken valves, it is crucial not to attempt to start the engine as this may result in more costly damage being caused to the cylinder head, pistons and cylinder bores. The bent valves above are a result of a fatigued timing belt that has broken. Replacing your timing belt is cheap insurance against costly engine damage. The other common type of valve failure is valve burn, or burnt valves.

Essentially this is caused by combustion gases escaping between the valve and valve seat when they are not sealing correctly. The hot combustion gases are forced past the valve which starts to burn away the edge of the valve, progressively getting worse the longer it is left without being rectified.

Normally this type of failure affects the exhaust valves only, but it can also damage the intake valves. Rough idle, reduced power, backfiring, and misfire are all symptoms of valve burn.

If your engine is showing symptoms like these, we recommend you get your car checked by a trusted mechanic, as continual driving with a burnt valve will cause more damage to your engine, and will in turn cost more to repair in the long run.

To help prevent this type of failure, there are a few things you can do. Maintain a clean, efficient cooling system so the engine does not run too hot, use good quality fuels to help prevent carbon build up on the valve seats, and have your mechanic regularly check the valve clearances are within specifications. If your vehicle is using an aftermarket L.