Exhaust manifolds are usually made from porous metals that expand and contract depending on the temperature. This makes them more prone to cracks over time. Once your car's exhaust manifold breaks, the engine's performance will be affected because of the unequal air-to-fuel ratio. Also, harmful exhaust gas will leak into the car's interior, putting yours and your passengers' health at risk. This is why a damaged exhaust manifold should be replaced immediately. If you're in the market for a replacement part, you should consider these three critical things so that you won't regret your purchase.
OEM or aftermarket?
OEM manifolds are typically made from cast iron, so they are inexpensive. But because of production cost constraints, some OEM manifolds are susceptible to rust and corrosion.Aftermarket manifolds, on the other hand, are engineered for optimum engine performance. They can be made from stainless steel, coated mild steel, or aluminized steel. However, aftermarket manifolds are more expensive than OEM.
Exhaust wrap, ceramic paint, or ceramic mixture?
Proper thermal insulation is essential to help prevent overheating inside your car's engine bay. Below is a list of the most common types of insulation used on an exhaust manifold.
- Exhaust wrap: This type offers excellent insulation because it's wrapped completely around manifolds. Though it's relatively cheap, it can cause premature manifold degradation.
- Ceramic paint: Usually sprayed or brushed onto manifolds, ceramic paint reduces the heat through radiation but not that much.
- Ceramic mixture: Because of its very good thermal insulation, ceramic mixture is commonly used on performance cars and race cars.
Stainless steel, aluminized steel, or cast iron?
If you're having a hard time choosing the best type of exhaust manifold, here's a list of the advantages and disadvantages of the common types of manifold.
- Stainless steel: This kind of exhaust manifold is rust resistant. It can also retain its chrome-like shine for a long time. However, despite these benefits, stainless steel manifolds are more expensive than other types.
- Aluminized steel: By forming a layer of oxide, aluminized steel prevents corrosion. Although it's cheaper and lighter than stainless and cast iron, it easily rusts once the oxide layer is scratched or dented.
- Cast Iron: Stock exhaust manifolds are made from cast iron, so they are affordable. However, they tend to be on the heavy side, and they don't boost engine performance that much.
When picking the right part, always make sure that you will buy from a trustworthy brand. Remember that even though price affects quality, you shouldn't compromise durability or your budget.