Oil leaks from your car are a hassle that can leave your driveway looking like a mess. One place your car can develop oil leaks from is the valve cover gasket, although the leak could be from another component, such as a damaged oil pan.
However, the valve cover gasket is the most likely culprit for an oil leak—and if left unchecked, it can cause your car’s engine to run low on oil, resulting in catastrophic damage.
As mentioned, a valve cover gasket leak can result in a pool of oil under your car. But there are a few other noticeable symptoms, which we’ll discuss below.
Common Signs of a Leaking Valve Cover Gasket
The valve cover (also known as a camshaft cover or rocker cover) is a plastic or metal cover fastened to the top of the engine’s cylinder head. The valve cover protects the valvetrain components while keeping oil in and contaminants out.
Inline or straight engines with one bank of cylinders have just one valve cover. On the other hand, engines with a ‘V’ or flat configuration have two valve covers.
As for the valve cover gasket, it provides a seal between the valve cover and cylinder head. When the valve cover gasket fails, it can result in the following problems:
Oil Running Down the Engine
An engine oil leak is the most common sign of a bad valve cover gasket. Because the valve cover is on the top of the cylinder head, the oil leak usually travels down the engine before reaching the ground.
Low Oil Level
A leaking valve cover gasket can eventually lead to a low engine oil level. If the leak is severe and you ignore it, the engine may run low on oil, causing internal damage.
The valve cover gasket can leak oil down on to the hot exhaust manifold, resulting in a burning smell.
Smoke Coming from the Engine Compartment
In some cases, you may also notice smoke from the engine compartment as oil from the valve cover gasket leaks down onto the exhaust manifold.
Valve Cover Gasket Replacement (Typical Four-Cylinder Engine)
Okay—so your valve cover gasket is bad, and you want to replace it. Should you do the job yourself?
Replacing a valve cover gasket is usually a fairly straightforward job. But on some vehicles, the valve cover is buried under other components, which can make removal more difficult.
It’s important to consult a repair manual or repair database to see what the job entails for your vehicle. That way, you can decide whether to tackle the repair yourself or leave it to a professional.
If you decide to do the job yourself, the following outline will give you an idea of what the task might involve in a typical, four-cylinder engine.
Tools & Supplies Needed to Replace a Valve Cover Gasket:
The tools needed to replace a valve cover will vary, depending on what type of car you have.
In general, however, you’ll need:
- Brake cleaner
- Gasket scraper (optional)
- Dead-blow hammer or rubber mallet
- Ratchet set (ratchet, sockets, and extensions)
- Sealant (some vehicles)
- Flathead screwdriver (optional)
- Torque wrench
- Repair manual or access to a repair database
- Safety glasses
Valve Cover Gasket Replacement Instructions:
Before we begin, keep in mind: all vehicles are different. The information below is generic and for entertainment and educational purposes only. Be sure to follow the factory repair information for your specific application.
Repair manuals, such as those from Chilton, are useful, but a subscription to a repair database is even better. ALLDATA and Mitchell 1 both have single-vehicle subscriptions for DIYers that provide detailed factory repair information.
You can learn more about accessing quality repair information in this article.
Valve Cover Removal on a Typical Four-Cylinder Engine:
- Put on your safety glasses.
- Disconnect and isolate the negative battery cable.
- Remove any components (i.e., covers, wiring harnesses, etc.) restricting access to the valve cover. In some instances, you may need to remove major components, such as the upper intake manifold.
- Remove the coil-on-plug ignition coils as outlined in our article on “how to replace an ignition coil”.
- Disconnect any hoses or electrical connectors attached to the valve cover. Remove the engine oil dipstick if needed.
- Remove the valve cover by pulling it up and away from the engine. If the cover does not come off easily, carefully tap on it with a dead-blow hammer or rubber mallet.
Caution: Once you remove the valve cover, the valvetrain will be out in the open. Keep the area free from dirt and debris. Be sure to retrieve any old sealant or gasket residue that happens to fall inside.
- Remove the old valve cover gasket from its groove.
Tip: It’s a good idea to replace the spark plug tube seals (if applicable) when replacing the valve cover gasket. To do this, carefully pry the old seal out with a flathead screwdriver. Then, tap the new seal into place using a dead-blow hammer or rubber mallet. You can learn more by watching this video:
Valve Cover Gasket Installation on a Typical Four-Cylinder Engine:
- Compare the new valve cover gasket to the old valve cover gasket to ensure that both are the same design.
- Thoroughly clean the gasket mating surface on the valve cover using brake cleaner and a clean rag.
- Thoroughly clean the gasket mating surface on the engine with brake cleaner and a clean rag. If you need to, you can use a gasket scraper to carefully remove stubborn residue from the engine. But be extremely careful: using a scraper on an aluminum surface can cause permanent damage.
- Install the new valve cover gasket in its groove.
- Although the valve cover gasket is typically installed dry, you may need to apply sealant to certain locations between the valve cover and the engine. Apply the sealant to the locations as specified in the repair manual or repair database.
- Reinstall the valve cover onto the cylinder head. Thread each of the bolts in by hand.
- Consult a repair manual or repair database to determine the proper torque and tightening sequence for the valve cover bolts. Then, use a torque wrench to tighten the bolts to the manufacturer’s specification.
Note: Some valve cover bolts have grommets. Be sure to replace the grommets with the new ones found in the valve cover gasket set.
- Reinstall any hoses or electrical connectors attached to the valve cover. Reinstall the engine oil dipstick if needed.
- Reinstall the coil-on-plug ignition coils as outlined in our article on “how to replace an ignition coil”.
- Reinstall any components (i.e., covers, wiring harnesses, etc.) removed during disassembly.
- Reconnect the negative battery cable.
- Give the sealant ample time to dry before starting the engine. Consult the product information for the proper dry time.
- Start the engine and double-check your work, looking for leaks. For a visual representation of how to replace a valve cover gasket, check out the video below:
Valve Cover Gasket Replacement Cost
After reading the outline above, you might decide valve cover gasket replacement is a job best left to a professional. If you decide to take your vehicle to a repair facility, expect to pay between $250 and $350 to replace the valve cover gasket.
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Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic.