What is an exhaust-manifold? What are the signs and symptoms of exhaust manifold loss? What are the causes for exhaust manifold failure What types of exhaust manifolds are there? How does the exhaust manifold function? Can the exhaust manifold ever be repaired?
What is Exhaust Manifold?
The exhaust manifold is used to extract exhaust gases from the engine. In order to make room for fresh air, internal combustion engines must have cylinders that can be moved around. Also, exhaust gases from the combustion process must be emitted. The exhaust manifold collects the combustion gases and then directs them to the turbocharger, catalytic converter, or turbocharger.
Most vehicles with an in-line system have only one exhaust manifold. “V” engines have 2. Turbocharged engines come with additional downpipes. There are exceptions and regulations. The exhaust manifold connects the engine cylinders’ exhaust ports. The exhaust manifold gasket prevents toxic exhaust gases from leaking between them.
What are the Exhaust Manifold Types
Cast iron (pig) and stainless steel make up the exhaust manifold. Cast iron exhaust manifolds can be durable and economical. Cast iron exhaust manifolds weigh more than steel. They can become fragile over time due to heat cycles, deformation and deterioration. Cracking can cause the engine check lamp to go on and make the vehicle run louder. The manifold crack can allow toxic exhaust fumes to leak into the vehicle’s interior. This can also happen if exhaust manifold gaskets fail or the mounting screws are damaged. This type of exhaust manifold is used in many fabricated vehicles.
Because they are more efficient and have better flow, tubular steel exhaust manifolds are popular in sports cars. Manufacturers prefer this manifold for non-sports vehicles like Jeep, but that is an exception. This type of exhaust manifold is available in mild or stainless steel depending on the preference of the automaker. The steel pipe that is used to make the manifolds is welded to both the cylinder head’s flanges and any points where it intersects. These manifolds will crack, just like cast iron exhaust manifolds.
Some vehicles have modified manifolds, also known as “Headers” With special fittings, instead of standard manifolds. These manifolds have a longer pipe diameter and can remove exhaust gases quickly through high-powered sweeping. OEM exhaust manifolds have been designed with fuel efficiency and long-term durability in mind. Maximum horsepower and torque are the main goals of headers. They are often mandrel bent and have equal length steel tubes so each cylinder has the same flow. You can adjust the headers to get more or less performance in specific areas of your engine’s power range. For maximum efficiency, the exhaust system will have to be completely replaced. The vehicle’s exhaust gas flow will increase faster, and the original exhaust system is not designed to handle this. It can cause clogging.
How does the ExhaustManifold Work?
A spark plug ignites the air-fuel mixture inside the cylinders. The exhaust valve opens after combustion and directs the exhaust gases to the exhaust manifold. The pressure inside the cylinder can push most of it out. However, the manifold’s purpose is to draw as much gas out as possible. This is known as “sweeping” . Remaining exhaust gases may cause poor combustion, which can lead to reduced power output. Some exhaust manifolds can condense or burn any remaining gases. Once all of the gases have been collected, they are sent to a catalytic converter before being sent to the exhaust system.
The oxygen sensor can be found on most exhaust manifold outlets. This sensor controls the oxygen level of exhaust gas. The sensor transmits this information back to the ECU to adjust each cylinder’s fuel/air mixture.
Why does the Exhaust Manifold Leak
Because they are the primary component that removes exhaust fumes from an engine, exhaust manifolds can be subject to extreme thermal stress. Vibrations also increase the pressure. The manifold can fail due to repeated heating and cooling cycles, material expansion, and repeated heating and cooling.
Cracked or broken exhaust manifolds are usually due to one of two factors: heat cycles and/or aging. The manifolds lose their ability to withstand heat, and cracks develop inside. These cracks can then become small holes. The second most common reason is the weakening, elongation and/or breaking of the studs or bolts that hold the manifold together to the cylinders.
A damaged gasket is one of the leading causes of exhaust manifold leakage. The gasket must be removed from the exhaust manifold to be replaced. A common problem is manifold corrosive, particularly in salty environments. Exhaust fumes can leak into the engine compartment if the manifold pipes are corroded. These fumes can get into the passenger compartment, causing poisoning.
What are the Signs of Exhaust Manifold Malfunction
- – A hissing or rattling sound coming from the engine
- – Very loud exhaust
- – A decrease in engine performance
- – High fuel consumption
- – Illumination (related to the emission systems)
- – Vehicle cabin emits an exhaust odor
- Visible cracks or soot formations around manifold
- – Exhaust gases from an engine can melt plastic components and cause a fire.
Leaky exhaust manifolds will produce a repetitive, rattling sound. This noise is louder when the engine is first started. As the engine warms, the manifold expands in order to seal the leak. The noise may then subside and disappear completely.
Leakage of the exhaust manifold can cause exhaust gas to leak into the cabin. This smell can be easily detected by cabin passengers.
Can the Exhaust Manifold be repaired?
You can repair or weld small cracks or leaks in your exhaust manifold. While large cracks might require more extensive repairs, this temporary solution is acceptable. The same problem may arise again. The structural integrity of your unit may be compromised if the crack that is causing the leak becomes too large. Leakage can lead to further problems like premature catalytic converter failure. The best solution is to replace your exhaust manifold in such instances.
Leaks from other parts of the exhaust system can present the same symptoms that the leak from the manifold. Before you attempt any repairs, make sure to check that the leak is not coming from the exhaust manifold.
