Mechanics

Valve Cover Gasket Replacement

Valve Cover Gasket
How to Replace a Valve Cover Gasket

When your engine is running, internal engine components are moving, shaking, and causing temperature changes throughout the entire engine. Consequently, all the moving parts need proper lubrication. Therefore, oil is pumped throughout the engine, and it is no surprise that oil is splashed around internally.

As normal preventative maintenance, the motor oil level should be checked every time the fuel tank is filled. If you notice that you are adding oil more often than usual, you could be leaking oil from the engine. One of the most common components to leak is the engine’s valve cover.

The valve cover is bolted to the top of the engine cylinder head. Its purpose is to allow access to cylinder head components such as valves, and the cam shaft on over head cam engines. Additionally, the cover prevents the oil used to lubricate the components from splashing and leaking from the engine.

When the valve cover is installed, there is a gasket between the valve cover and the engine cylinder head. The gasket seals oil from leaking. However, over time the gasket can become dry, cracked or damaged from heat. As a result, motor oil can leak down the sides of the engine, onto the exhaust manifolds, and even onto the spark plugs and ignition wires. When this happens, the gasket needs replaced.

If you find there is a leak, check to make sure the bolts that hold the cover to the cylinder head are tight. When checking, gently tighten the bolts. If they are over tightened, it can cause the gasket to break or compress away from the sealing area and create a larger leak.

Parts and Supplies needed to Replace a Valve Cover Gasket

1 - New valve cover gasket

2 - Protective clothing

3 - Eye protection

Tools Needed to Complete this Job

1 - Sockets and socket wrench

2 - Scraper

3 - Screw drivers

4 - Shop rags

Instructions

Step 1 - Park the vehicle on a flat location, place it in park (AT) or in reverse (MT), apply the parking brake, open the hood, disconnect the negative battery terminal, and allow the engine to cool.

Step 2 - Locate the valve cover. It is located on the top of the cylinder head. Carefully, remove any wiring harnesses, PCV valve, vacuum hoses and other items that restrict access to the valve cover. I recommend that you mark anything you remove to help reattach it at the end of the job.

Step 3 - Locate and clean dirt and oil from valve cover bolts. They will be at the engine side of the cover. When cleaned, identify the bolt size.

Step 4 - Using your socket wrench, remove the bolts from the valve cover and place them in a safe place.

Step 5 - Remove the valve cover from the engine cylinder head. NOTE: Often times, the valve cover will still feel attached even after the bolts are removed. Take a screw driver and gently pry the valve cover from the cylinder head.

Step 6 - At this point, you need to properly clean all old gasket material from both the cylinder head and the valve cover. Using your scraper, scrape the old gasket off both surfaces. Avoid getting gasket material in the cylinder head.

Step 7 - Once all old gasket material is removed, clean any sludge from the valve cover and any that has accumulated on the cylinder head. Parts solvent works well for this, or you could use any auto product that is designed to remove oil or sludge.

Step 8 - Once everything is clean and dry, check the valve cover to make sure it isn’t bent or warped which can cause problems with a proper seal. You can use a straight edge to check it.

Step 9 - Now it is time to replace the gasket. Some valve covers are grooved to hold the gasket in place. Regardless, attach the gasket to the valve cover making sure it is properly positioned.

Step 10 - Carefully place the valve cover back on the cylinder head making sure the gasket stays positioned. Install the bolts and tighten the valve cover to the manufacturer’s recommend torque specifications. NOTE: Do not over tighten.

Step 11 - Replace any items that needed removed to access the valve cover, check and refill oil if needed, and connect the negative battery terminal.

Step 12 - Start the engine and check for leaks.

Best Practices

  • Avoid allowing gasket material and dirt from getting into the engine
  • Do not over tighten the valve cover
  • Always check oil level every time the fuel is refilled

If further technical assistance is needed, our certified car repair technicians are ready to answer your car questions. For manufacturer specific repair information visit - Car Repair Manuals

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AUTHOR


Written by
Co-Founder and CEO of 2CarPros.com
35 years in the automotive repair field, ASE Master Technician, Advanced Electrical and Mechanical Theory.


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Article first published (Updated 2013-08-16)