Exhaust Gasket Guide: Function, How to Replace, and FAQs

Exhaust gaskets play an important part in your car’s exhaust system. Driving with a faulty one could lead to leaks of toxic gases, damage to other engine components, increased emissions, a failed emission inspection, and an illuminated check engine light.

To keep your vehicle in tip-top shape, it’s best to learn more about this component, how it works with the exhaust system, and how to replace it.

What Are Exhaust Gaskets?

Exhaust manifold gaskets can withstand extreme pressure and temperatures. They’re typically on the mounting surface of the exhaust manifold (the engine), which can reach temperatures up to 1,200 degrees F.

These gaskets help seal the gap between the engine block and the exhaust pipe. They prevent leaks and ensure exhaust gas flows through the catalytic converter.

Are Exhaust Gaskets Different From Donut Gaskets?

While they work similarly, exhaust gaskets are different from donut gaskets.

Donut gaskets are round-shaped and fit from the exhaust manifold to the exhaust pipe or between exhaust pipes. They prevent leaks and maintain the proper pressure within the exhaust system.

To be more specific, donut gaskets seal the connection between the exhaust manifold and the front pipe of the exhaust system. Exhaust gaskets, on the other hand, seal the connection between different exhaust components, such as the exhaust manifold, catalytic converter, and muffler.

Exhaust gaskets also serve a more general purpose compared to donut gaskets, which are specifically shaped for flared joints.

Different Materials Used For Exhaust Gaskets

Exhaust gaskets come in different materials, including composite graphite, multi-layer steel, ceramic coating, and “sandwich type,” which is composed of aluminum, copper, and steel.

Composite Graphite

Gaskets made of composite graphite have superior performance and are lighter than other types. They’re less likely to corrode because they’re resistant to coolant, gasoline, alcohol, and oil. In addition, composite graphite doesn’t easily crush, split, shrink, or squeeze, making it durable and long-lasting.

Composite graphite gaskets are also easy to make because composite is easily trimmed for exact fit on modified parts.

Multi-Layer Steel

Multiple sheets of carbon or spring steel with a sealing material between them are used to make exhaust gaskets. The layers provide better sealing around critical areas, such as the cylinder bores, oil passages, and water ports.

Multi-layer steel (MLS) gaskets are coated with materials like Viton for better heat resistance. Due to their design, these gaskets require less clamp load, resulting in less bore distortion.

MLS gaskets also come in various thicknesses, allowing flexibility in achieving the desired overall gasket thickness. Multi-layer steel gaskets range from extra thin (.018) to thicker (.140).

Multi-Layer Steel With MOS

This type of exhaust gasket is basically MLS but with a dry film lubricant coating made of molybdenum disulfide (MOS) to reduce wear.

MLS with MOS gaskets can also withstand extreme temperatures without damaging its structural integrity because of MOS’ high compressive strength and ability to adhere to sliding surfaces.

Ceramic Coating

Ceramic coatings are essentially thermal barriers that reflect heat back into the exhaust system. It helps maintain higher exhaust gas temperatures, improving performance and efficiency.

Additionally, gaskets with a ceramic coating withstand road grim, water stains, and other substances, which make them durable and long-lasting.

Sandwich Type (Multiple Materials)

Sandwich-type exhaust gaskets are named as such because they have an outer layer made of thin sheets of aluminum, copper, steel, and another type of metal.

They also have a center layer made of graphite. The outer layer provides structural strength and durability, while the graphite in the middle acts as a sealant.

This type of exhaust gasket can withstand high temperatures thanks to the metal and graphite. It’s also versatile, as you can use sandwich-type gaskets for turbo gaskets, exhaust gaskets, and cylinder head gaskets.

What to Look for When Choosing an Exhaust Gasket

If you need to replace your exhaust gasket, you must know what factors to consider to ensure you get a high-quality replacement.

Heat-Tolerance

Look for a heat-tolerant exhaust gasket because it’s constantly exposed to high temperatures. If the facing/filler material can’t handle the heat, the seal might wear out and cause leaks, which could result in a noticeable loss in power and acceleration.

In addition, extreme temperatures could cause stress through the contraction and expansion of materials. This could deform the gasket if it can’t tolerate the heat.

Metal Reinforcement

Exhaust gaskets with reinforced metal are a great investment because they can tolerate extreme temperatures and have long lifespans.

Abrasion Resistance

Abrasion-resistant gaskets have increased hardness and toughness, making them less prone to damage and wear and tear.

These gaskets are highly recommended if your exhaust system has joints with high thermal motion (two joints made of two or more dissimilar metals with varying contraction and expansion rates under heat).

Low Creep Relaxation

Lastly, exhaust gaskets with graphite filler in the middle (sandwich types) have low creep relaxation. That means the gasket material won’t lose much thickness due to exposure to extreme heat. This helps the gasket keep the seal intact because it will maintain reliable flange loading.

Can You Replace a Bad Exhaust Gasket Yourself?

It’s usually best to leave exhaust gasket replacement to the pros.

In older vehicles, the exhaust manifold is in plain sight, but the bolts holding it are sealed to the metal because of high heat and intense cooling, making the bolts hard to remove.

Meanwhile, in modern vehicles, the manifold is behind a myriad of wires and hoses that must be removed to access the part. Once the job is done, the wires must be reattached or returned to their place.

How to Replace a Damaged Exhaust Gasket

As mentioned, it’s best to leave the process of replacing a damaged exhaust gasket to professionals. However, if you’re willing to try your hands at DIY, you’ll need the following tools and equipment:

• Gasket scraper
• Cleaning equipment
• Torque wrench
• Socket set
• Wire brush
• Sandpaper

The process usually involves the steps below, but note that some steps can vary depending on the vehicle:

Remove the Old Gasket

Once the engine is cold enough to touch, look for the old exhaust gasket. It’s usually located where the exhaust pipe meets the exhaust manifold or where two sections of the exhaust pipe connect.

Remove the exhaust manifold, header, pipe, and flange, as they’re all attached to the gasket. Use a gasket scraper to remove any residue and remnants left by the old gasket material. Be sure the surfaces are clean and smooth to properly seal the new gasket.

Clean the Area

Clean the surface where the new gasket will sit using a solvent to remove dirt and oil. Clean it gently and double-check to make sure there are no damages or irregularities that could prevent a good seal. Use a wire brush or sandpaper to remove any rust or debris.

Align and Install the New Gasket

Align the new gasket with the holes and contours on the surfaces. You’ll need to make sure the port holes in the gasket align with the exhaust ports on the engine and manifold/header.

Place the gasket onto the surface and reattach it by hand-tightening the bolts in a crisscross pattern to apply even pressure. Afterward, use a torque wrench to tighten the bolts. Check the manufacturer’s recommended torque to avoid over-tightening and damaging the gasket.

Afterward, reattach the exhaust manifold, header, pipe, and flange.

Final Checks

Lastly, start the engine and inspect for any signs of leaks. You may also need to retighten the bolts a bit once the engine reaches its operating temperature.

FAQs About Exhaust Gaskets

Here are some of the frequently asked questions about exhaust gaskets.

Where Is the exhaust gasket?

You can find exhaust gaskets between the exhaust pipes and the exhaust manifold.

How do I know if my gasket needs replacement?

Some signs of a bad exhaust gasket include hissing or tapping noises, poor fuel economy, the smell of burning materials, and smoke.

Can I drive with a bad exhaust gasket?

It’s best to avoid driving a car with a bad exhaust gasket because it could lead to poor fuel economy, which could take a toll on your wallet.

Are exhaust gaskets reusable?

You can reuse exhaust manifold gaskets only if they’re repairable and if it’s necessary. However, it’s still better to replace them once they show signs of damage.

How Much Does It Cost to Replace an Exhaust Gasket?

Replacing an exhaust gasket can cost between $100 and $400, depending on the gasket’s brand, how difficult it is to access the gasket in the vehicle, and other factors.

Where to Get a New Exhaust Gasket for Your Vehicle

Exhaust leaks can be a nightmare to deal with, and a leaky gasket is usually to blame. Don’t worry, though, because CarParts.com is the best place to get a replacement exhaust manifold gasket, and finding one will only take a few minutes of your time.

We have a great selection of precision-engineered exhaust manifold gaskets that have passed the highest quality control standards from the most reputable names in the industry. They’re made from only the finest materials available, so you can rest assured that our exhaust manifold gaskets can deliver maximum durability and dependability.

Enter your vehicle’s specifications into our vehicle selector to start shopping for OE-grade exhaust gaskets. You can also use the search filters to find a gasket according to your preferred brand, price range, quantity, and more.

Never go over budget when you shop from us. All our products come with a low-price and lifetime replacement guarantee, helping you get the best value for your money. Order now, and we’ll deliver what you need straight to your doorstep in as fast as two business days.

Don’t miss out on the best deals on the market, and shop for an exhaust manifold gasket today!