Replace Worn Engine Gaskets to Stop Oil and Coolant Leaks

Gaskets - The Unsung Heroes Keeping Your Engine Sealed

Is your car leaking oil or other fluids? Do you frequently have to top up the coolant? If so, worn out gaskets may be to blame. Gaskets are essential components that seal your engine and prevent leaks. Ignoring worn gaskets can lead to overheating, oil burning, emissions issues, and even complete engine failure down the road.

What Exactly Are Gaskets?

Gaskets are made from materials like rubber, cork, silicone, or graphite and are used to seal two components in an engine. Some common locations include:

• Between the cylinder head and engine block
• On valve covers
• On exhaust manifolds
• Between the intake manifold and cylinder head
• On the oil pan

Gaskets fill the slight imperfections in machined metal components to provide a leak-proof seal. They prevent combustion gases and engine fluids like oil and coolant from escaping.

Signs of Failing Gaskets

Here are some common indicators your engine gaskets may be worn out:

1. Oil leaks - Look for oil dripping from below the valve covers or oil pan.
2. Coolant leaks - Check for leaks around the water pump, radiator, or heater hoses.
3. Exhaust smoke - White or blue smoke from the tailpipe pointing to bad seals.
4. Overheating engine - Coolant leaks can lead to overheating.
5. Coolant in oil - A sign of a blown head gasket allowing coolant and oil to mix.

Replacing Worn Gaskets

Many gaskets like valve cover and oil pan gaskets can be replaced by DIYers with basic mechanical skills. Here are some tips:

• Consult your repair manual for step-by-step instructions.
• Allow the engine to fully cool before starting.
• Remove old gasket material thoroughly to prep the surface.
• Apply gasket sealant if recommended by the repair manual.
• Torque bolts to spec when re-installing parts.

Replacing more complex gaskets like the cylinder head gasket often requires special tools and expertise. Consult a professional mechanic for jobs like these.

Preventing Premature Gasket Failure

To help your gaskets last, follow these tips:

• Maintain proper coolant strength and change intervals.
• Keep oil changed regularly.
• Watch for leaks and address them quickly.
• Don't reuse old gaskets during repairs.
• Torque bolts to manufacturer specs.

While they don't get much fanfare, proper gaskets are critical for safe engine operation. Address any leaks promptly to avoid damage down the road.

Main Engine Gaskets and Where They Go

Modern engines have many gaskets that serve as seals between components. Here are some of the most common gaskets you'll find under the hood and where they are used.

Cylinder Head Gasket

This crucial gasket seals the cylinder head to the engine block. It:

• Prevents combustion gases from leaking into the coolant passages.
• Seals oil and coolant passages between the cylinder head and block.
• Withstands high temperatures and pressures.

A failed cylinder head gasket can lead to cooling system leaks, oil burning, and even hydrolock if coolant leaks into the cylinders.

Exhaust Manifold Gasket

The exhaust manifold gasket seals the manifold to the cylinder head. It:

• Withstands high exhaust temperatures.
• Prevents exhaust leaks.
• Is often made of multilayer steel for durability.

Exhaust leaks can cause noisy operation, reduced engine performance, and potentially dangerous carbon monoxide entering the cabin.

Valve Cover Gasket

This gasket seals the valve cover to the cylinder head. It:

• Contains cylinder head oil and prevents leaks.
• Is usually made of rubber or cork.
• Should be replaced whenever the valve cover is removed.

A leaking valve cover gasket can drip oil onto sensitive engine components like the exhaust manifold.

Intake Manifold Gasket

The intake manifold gasket seals the intake manifold to the engine. Key traits include:

• Prevents air and fuel leaks.
• Withstands heat from the cylinder head.
• May be made of paper, plastic, rubber, or metal.

Leaks can cause poor engine performance, stalling, or misfires in affected cylinders.

Be sure to address any gasket leaks promptly to avoid creating bigger issues down the road.

Gasket Materials - Properties and Uses

Gaskets come in a variety of materials, each with their own advantages and disadvantages. Here is an overview of some common gasket materials used in engines.

Rubber

Rubber is a popular gasket material thanks to properties like:

• Flexibility - Conforms to surface irregularities.
• Resilience - Returns to original shape after compression.
• Oil resistance - Handles contact with engine oil.

Drawbacks include degradation from heat and wear over time. Common uses are valve cover, oil pan, and timing cover gaskets.

Cork

Benefits of cork gaskets:

• Natural compressibility fills small voids.
• Good thermal insulation.
• Handles temperatures up to 700°F.

However, cork can dry out and must be replaced after several openings. Cork is often used for valve cover and oil pan gaskets.

Silicone

Key silicone gasket traits:

• Temperature resistance up to 500°F.
• Excellent flexibility and sealing.
• Superior oil and chemical resistance.

Silicone can be damaged by sharp edges during installation. It is used for valve covers, oil pans, and water pumps.

Graphite

Graphite offers:

• Resistance to fuels, oils, and chemicals.
• Ability to conform to surface flaws.
• High heat tolerance up to 1,200°F.

The downside is gradual compression over time. Graphite is often used in exhaust manifold gaskets.

PTFE

PTFE (Teflon) gaskets provide:

• Inertness - chemically stable.
• Non-stick properties.
• Handle temperatures from -450°F to 500°F.

PTFE has poor cold flow characteristics. It is commonly used in valve cover gaskets.

Consider the needs of each gasket application when selecting a replacement material.

Common Gasket Issues and How to Fix Them

Gaskets are subjected to extreme pressures and temperatures. Here are some typical problems that can develop and how to address them.

Blown Head Gasket

Symptoms of a blown head gasket include:

• Overheating engine.
• Exhaust smoke.
• Coolant leaks.
• Coolant in the oil.

Repairing involves removing the cylinder head, scraping both mating surfaces completely clean, and installing a new head gasket. Torque specifications must be followed exactly. This is a complex job best left to a professional mechanic.

Leaking Valve Cover Gasket

Signs include:

• Oil dripping from the valve cover area.
• Low oil level.
• Oil on spark plugs.

Replace the valve cover gasket by cleaning the sealing surfaces, applying fresh gasket sealant, and re-installing the valve cover with proper torque. Be sure to use a new gasket.

Damaged Exhaust Manifold Gasket

You may notice:

• Loud exhaust noise.
• Smell of exhaust fumes in the cabin.
• Check engine light.

Remove the manifold, scrape both sides completely clean, and install a replacement manifold gasket. Check for warpage. Torque bolts in the pattern specified by the manufacturer.

Leaking Oil Pan Gasket

Check for:

• Oil dripping under the engine.
• Low oil level.
• Oil on the underside of the engine.

To fix, drain the oil, remove the oil pan bolts, clean the surfaces thoroughly, apply fresh gasket sealant, and reinstall the pan with new gasket. Refill engine oil.

Detecting gasket issues early and completing repairs helps avoid further damage.

Gasket Material

Gaskets are mechanical seals used in fluid processing and handling equipment to prevent process fluids from escaping and contaminants from entering sensitive areas. The material of a gasket significantly influences how it performs in the intended application. There are numerous gasket materials available, each of which offers unique characteristics that make it suitable for different applications. Here are some of the most common and versatile non-metallic gasket materials:

Natural rubber: a good all-around, general-purpose gasket material that is incredibly water-resistant and works very well with metal surfaces. It is great to use with water pumps and pipes for its good shock and vibration resistance qualities.

Silicone rubber: a popular choice for gasket material due to its flexibility and resistance to high temperatures. It has good electrical insulating properties and is weather-resistant, making it highly suitable for outside applications.

Neoprene rubber: suitable for many applications, particularly effective with silicone greases, oils, water, and petroleum oils.

Cork: high compressible and flexible than many other gasket materials. With their expansive nature, these gaskets were preferred as they can hold a strong seal. Combined with elastomer bindings, cork gaskets which are high in flexibility and compression, are perfect for applications involving oil, fuel, and solvents.

Non-asbestos types of gaskets: created from a compressed fiber material and a binding elastomer. Non-asbestos types of gaskets are used across many different applications, involving water, oil, acid, and steam.

FKM fluoroelastomer rubber: a common material for gaskets that require resistance to high temperatures and chemicals.

Best Gasket Material For Water Pump

When it comes to selecting the best gasket material for water pumps, there are several options to consider. Here are some of the most popular materials that perform well with water:

Natural rubber: This is a good all-around, general-purpose gasket material that is incredibly water-resistant and works very well with metal surfaces. It is great to use with water pumps and pipes for its good shock and vibration resistance qualities.

Platinum Cured Silicone: This is a very good all-rounder and can be used for both fresh and saltwater. It is also a firm favorite in the food, beverage, and medical industries because it has no peroxide by-products. This means that if you cut a gasket from platinum-cured silicone, the gasket itself will not taint the water at all.

Neoprene rubber: This material is excellent for outdoor use and is highly resistant to water. It is often used to protect electrical systems from bad weather.

Non-asbestos gaskets: These are preferred for pumps as they are safer, more environmentally friendly, and have better heat and chemical resistance than other gaskets.

Permatex Water Pump & Thermostat RTV Silicone Gasket Maker: This is a noncorrosive silicone gasket material formulated for water pumps and thermostat housings. It has the highest water-glycol resistance available in RTV silicone and superior adhesion and flexibility. It can be used as a gasket maker or dressing.

It's important to note that the ideal gasket material for water pumps may vary depending on the specific application and the type of water being used. For example, if the water is for drinking, the WRAS (Water Regulations Advisory Scheme) recommends EPDM rubber for use with drinking water in the United Kingdom. The rubber should conform with British Standard regulations BS6920 and BS EN681-1 to ensure that drinking water does not become contaminated or have its taste affected by coming into contact with the rubber.

Gasket Sheet Types

There are many types of gasket sheet materials available, each with unique characteristics that make them suitable for different applications. Here are some of the most common types of gasket sheet materials:

1. Rubber: Rubber comes in several formulations and grades, making it ideal for a wide range of applications with varying environmental and operating conditions. It can be processed by many different manufacturing processes, depending on the part and production specifications.
2. Non-asbestos sheet material: Non-asbestos materials are considered the most reliable option for all sealing flanges and are used in various applications. As the name would suggest, non-asbestos sheet material gaskets are cut from sheet materials that do not contain asbestos. Since the 1980s, non-asbestos materials have replaced asbestos as the industry standard. Aramid, fiberglass, mineral fiber, carbon, and graphite are commonly replaced fibers for asbestos.
3. Flexible graphite: Flexible graphite gaskets have superior compressive strength and recovery with very little creep. Three common types of graphite gasket sheets are reinforced (tanged, metal, metal foil, or polymer) .
4. Fluorocarbon: Fluorocarbon gaskets have a flat cross-section and are reusable for non-critical applications. They are widely used for applications that require frequent reassembly. Fluorocarbon gaskets are an alternative to copper gaskets and used to seal conflat flanges. They are not used for high-temperature applications since they lose their strength with increased temperatures.
5. Sponge materials: Gaskets made from sponge materials are mostly employed when low compressional forces. Sponge materials are the choice when:

The gasket must be compressible

The gasket must be able to conform to irregular surfaces

The gasket must be able to seal against low-pressure differentials

1. Elastomer: Elastomer gasket materials are used in many applications, including automotive, aerospace, and industrial. They are available in many different materials, including Nitrile (NBR) Buna, EPDM, FKM (Viton), and more.
2. Corrugated metal: Corrugated metal gaskets are reliable and cost-effective gaskets for flanges and heads where bolt loading is adequate. The constant load, or pressure, to which the gasket is exposed creates the sealing effect. This gasket type is used in various applications as they are capable of withstanding harsh environments such as those in steam transfers or hydrocarbon.
3. Paper: Paper gaskets are made on a paper machine that takes pulp and turns it into a sheet. The pulp process allows gasket manufacturers to convert many types of materials into a sheet without the cost of blending it with rubber. Non-asbestos gasket materials are generally made in a batch process that blends fibers with rubber and is compressed on a rubber calendar process.
4. PTFE and PTFE composites: PTFE and PTFE composites are used in applications that require chemical resistance, high-temperature resistance, and low friction. They are also used in applications that require electrical insulation.

• Gaskets - The Unsung Heroes Keeping Your Engine Sealed
• What Exactly Are Gaskets?
• Signs of Failing Gaskets
• Replacing Worn Gaskets
• Preventing Premature Gasket Failure
• Main Engine Gaskets and Where They Go
• Cylinder Head Gasket
• Exhaust Manifold Gasket
• Valve Cover Gasket
• Intake Manifold Gasket
• Gasket Materials - Properties and Uses
• Rubber
• Cork
• Silicone
• Graphite
• PTFE
• Common Gasket Issues and How to Fix Them
• Blown Head Gasket
• Leaking Valve Cover Gasket
• Damaged Exhaust Manifold Gasket
• Leaking Oil Pan Gasket
• Gasket Material
• Best Gasket Material For Water Pump
• Gasket Sheet Types