EXHAUST MANIFOLD AND COMMON PROBLEMS
An exhaust manifold is a system which is used to vent exhaust gases away from an engine. The exhaust manifold pipe is connected to the engine block, and the exhaust of each cylinder is collected and introduced into the exhaust manifold with divergent pipes.
Working Principle of Exhaust Manifold
When the pistons in the engine reach the exhaust stroke, they push the exhaust fumes up into the gas manifold. The manifold consists of a series of pipes which connect to the cylinders and then consolidate in a central large pipe which vents to the exhaust pipe. A series of gaskets are used to create tight seals so that exhaust cannot escape from the cylinders. The main requirement for the exhaust manifold is to minimize the exhaust resistance and avoid mutual interference between the cylinders. When the exhaust is too concentrated, there will be mutual interference between the cylinders. That is to say, when one cylinder exhausts, it happens to encounter the exhaust gas from other cylinders that is not completely discharged. In this way, the exhaust resistance will be increased and the output power of the engine will be reduced. The solution is to separate the exhaust of each cylinder as far as possible, one branch for each cylinder, or one branch for two cylinders, and make each branch as long as possible and form independently to reduce the mutual influence of gas in different pipes.
Common Faults of Exhaust Manifold
(1)One of the most common problems which can arise with an exhaust manifold is damage of the exhaust manifold flange. In this case, the manifold needs to be unbolted so that the gasket manifold can be removed and replaced.
(2)Another common problem is rust. If rust erodes the manifold pipes, they begin to leak exhaust into the engine compartment, which can get into the car, posing a danger to passengers and drivers.
(3)The differing pipe lengths can also lead to an issue known as back pressure, which forces the engine to work harder to push the exhaust fumes out. This can be resolved with a manifold part called a header, which uses pipes of the same length to reduce back pressure. Headers are fitted on high performance cars and race cars to increase efficiency. Reducing the amount of work the engine needs to do contributes to higher performance operation, and can make a critical difference with some vehicles.
In summary, if the exhaust manifold fails, the technician should be contacted to suggest repair or replacement based on the nature of the problem. If the driver notices a drop in performance or a change in the way the vehicle is maneuvered, it is best to discuss the problem with the mechanic to determine if there is a functional problem with the vehicle that could cause the change. Paying attention to changes is important for the longevity and performance of the vehicle and driver’s health and safety.
