When it comes to sealing an engine from oil leaks, the gasket is a vital component that prevents oil leaks, but it has not been given any recognition from most car owners.
The valve cover gasket serves as a shield that helps to keep your engine oil from leaving your car in-between the head cylinder and the valve cover itself.
Although the valve cover gasket is shielded from both up and downsides, it is very delicate and prone to damage from the sides since it is manufactured with plastic and rubber.
Over time, the gasket becomes brittle and dries up or crack due to exposure to heat. When this happens, the gasket will lose its value, causing severe issues like low engine performance and oil leaks.
To prevent these issues, you have to know the Symptoms of valve cover gasket leak.
What is the valve cover gasket?
Valve cover gasket is one of the most important gaskets in the engine that prevents your valve cover from oil leaks. It is placed in between your valve cover and the cylinder heads. Valve covers are made of rubbers or plastics.
As we all know, the oil pump sends pressurized oil to the head cylinder to enable adequate lubrication to the valves and the mechanism that drives them.
As the oil pump sends the oil to the cylinder head, oil clings to the surface of the valve cover, and this oil will escape if there are any little openings.
In most cars, tiny bolts are used to fasten the valve cover together with the cylinder head. Without the valve cover gasket, there will be a tremendous amount of oil leaks.
What Does the Valve Cover Gasket Do?
The valve cover protects some of the most vital and carefully calibrated parts of your vehicle, and keeps the high pressure oil there to lubricate it all. The valve cover gasket is exactly what it sounds like, a gasket for the valve cover.
It essentially maintains the seal between the valve cover and the cylinder head, and prevents oil from escaping.
The gasket is usually made of silicone, rubber, or cork and provides a cushion for the seal. With use though, the gasket is gradually worn down by the oil and heat and can eventually no longer properly serve its purpose.
Valve Cover Gasket Location
The valve cover gasket is located between the motor and the valve cover. You will find the valve cover sitting on top of the motor. It’s the hard cover protecting the valves and engine components.
The gasket is used to create a tight seal between the engine and the valve cover. Often, this part fails due to old age and requires replacement. To replace the valve cover gasket, you must remove the valve cover as well.
What Can Cause a Valve Cover Gasket to Fail?
While all valve cover gaskets are prone to leakage with time, several different factors can also play a key role in the depletion of such a gasket’s structural integrity. The vast majority of which are at least partially maintenance-related in nature.
#1. Infrequent Oil Changes.
Perhaps the most significant cause of premature valve cover gasket failure is infrequent engine service. Fresh engine oil, which is changed at a regular interval, contains a number of additives that are intended to prevent gasket deterioration.
With time these additives begin to break down, which in turn, leaves an engine’s valve cover gasket(s) vulnerable to accelerated wear and aging. This often occurs when items of routine maintenance are ignored for extended periods of time.
#2. Overheating.
Another leading cause of valve cover gasket failure is overheating. All engines are intended to operate at a predetermined temperature.
If this predetermined value is exceeded, as in the case of overheating, an engine’s gaskets become heat stressed, which poses an accelerated risk of cracking and blowout.
Overheating is not only hard on an engine’s valve cover gasket(s), but also jeopardizes the integrity of other vital seals, such as the head gasket. It is not uncommon to find multiple failed gaskets on a single engine, in the case of severe engine overheating.
#3. Over/Under Tightened Valve Cover Bolts.
Additionally, previously replaced valve cover gaskets often begin leaking in short order, if an engine’s valve cover bolts are not properly torqued upon installation.
Over-tightening of these bolts can lead to improper gasket seating or pinched/flattened gasket surfaces. On the other hand, the under-tightening of these bolts often prevents a suitable seal from ever forming between each metallic surface.
Valve Cover Gasket Leak symptoms
The most common symptoms of a bad valve cover gasket are external oil leaks and a low engine oil level when you check the dipstick. You may also notice a burning smell after acceleration. In some cars, it can also result in a misfiring engine or a check engine light.
Here is a more detailed list of the signs of a bad or leaking valve cover gasket to look for:
#1. Oil Leaks.
Whenever you see oil leaking out under your vehicle, it’s alarming. However, oil leaks are caused by many issues, so it’s not necessarily a tell-tale sign of a failed valve cover gasket alone.
Still, if you notice oil leaking from the valve cover area, you can assume that the gasket has gone bad. Inspect the area around the gasket to see if any oil is seeping out.
Initially, the oil leakage will be minimal, getting worse as time goes on. After some time, it could even coat the valve cover surface, causing a thick layer of dirt to also accumulate on the valve cover.
If you allow the oil to continue leaking, you risk more extensive engine repairs down the road. Plus, this symptom puts additional wear on the belts and hoses, as the oil softens the rubber on the belts and hoses, eventually causing premature failure.
#2. Low Oil.
It’s vital to check your engine’s oil levels regularly. When the oil gets too low, it’s often a sign of a problem, especially when it occurs frequently.
The engine operates as a sealed system, so oil shouldn’t be disappearing unless something is wrong. Start by checking the valve cover for signs of leaking.
While you wait for a valve cover gasket repair, make sure you keep topping off the oil. Running the engine without the proper amount of lubrication can cause the engine to cease and fail.
#3. Burning Smell.
The smell of burning oil should always cause alarm. As the oil leaks out of the valve cover, it can easily drip onto your car’s hot engine and exhaust. What you are left with is the undeniable smell of burning oil.
This odor becomes overpowering when you pop the hood, even if you can’t see the oil burning. Whenever you smell burning oil, you should assume that there is a risk of a car fire and stop driving immediately.
#4. Misfiring Engine.
When the car engine misfires, there are many causes that contribute to poor performance. One of the most common reasons for misfiring is a defective spark plug or issue in the fuel system. However, you shouldn’t overlook the possibility of a bad valve cover gasket.
The valve cover sits above the spark plugs. When the gasket fails and allows oil to leak onto the car’s spark plugs, fluid can get into the openings. As oil builds up, the spark plugs cannot work properly and foul out.
This causes the spark plug to fail, reducing the ignition of the air and fuel mixture. What you are left with is a misfiring engine that creates a rough ride. It can also lead to an engine fire when not dealt with immediately.
#5. Dashboard Indicator Lights.
Some people rely on the dashboard warnings to tell them when something is wrong. If you haven’t been checking the oil, this might be your first indication of a problem.
The Oil Warning Light might alert you to low pressure or a lack of lubrication in the engine. You might also see the Check Engine Light when there is a valve cover gasket defect.
Either one of these indicators is telling you that there is a critical issue that should be addressed immediately.
Is a Valve Cover Gasket leak serious?
In the vast majority of cases, a valve cover gasket leak is not considered to be extremely serious. This is especially true of minor leaks, which do not heavily contaminate an engine’s external surfaces.
Generally, a valve cover gasket leak is only considered to be serious if it becomes severe enough to cause significant oil loss.
Additionally, a valve cover gasket leak that causes a misfire condition is also cause for concern. This occurs when run-off from a leak leads to the presence of oil in a spark plug well, thereby contaminating a spark plugs electrode and insulator.
In any case, it is considered good practice to replace a leaking valve cover gasket within a reasonable amount of time. A leak of this nature will only progress in severity, eventually reaching a level of severity consistent with that described above.
Being proactive with such repairs helps to minimize the chance of any drivability-related symptoms.
How Long Should the Gasket Last?
The life expectancy of a valve cover gasket(s) in an engine is often based on a number of factors, such as the make and model of the engine, the frequency of routine engine maintenance, and any motorist’s driving habits.
Some OEM gaskets will be naturally better than others and therefore will offer a longer service life, while valve cover gaskets in a consistently well-maintained engine, will always be more likely to last longer than that of a neglected engine.
Another interesting fact about engine gaskets is that those found in a vehicle’s engine that are driven infrequently are more susceptible to failing sooner, as they become dry and brittle, just from resting.
But, on average, you can expect to get approximately 40,000-60,000 miles out of your engine’s valve cover gaskets, and that should be with little to no issues. In fact, in some cases, gaskets like these last a significantly longer time.
Valve Cover Gasket Materials
Valve cover gaskets all have one job (to seal properly to prevent oil leaks), but their make-up determines how well they do it. Below are some of the more common types of materials used for valve cover gaskets.
Plastic
Plastic valve cover gaskets have become more common (and popular) with the recent surge in “plastic” valve covers (common in modern vehicles). They are lightweight, fairly durable, and have some thermal resistance.
Plastic valve cover gaskets may not be suitable for older engines used in higher operating temperatures, as they tend to deteriorate quickly in extreme heat.
Rubber
Rubber valve cover gaskets made from silicone or nitrile rubber offer the best thermal resistance and longevity.
While not as durable as a plastic cover, they are better than cork and offer many temperature variations without changing shape and risking a leak. In general, rubber and silicone gaskets are relatively higher in cost than other gaskets.
Cork
Cork has been a traditional material for valve cover gaskets due to its lower cost and easy installation. Cork provides reasonable sealing for most engines, but it isn’t as good as rubber or plastic gaskets and probably not as durable.
Cork valve cover gaskets tend to compress only over time and can easily be replaced and filled more often, and could fall short in high temperature applications.
Metal
Metal gaskets are typically manufactured from aluminum or steel, offer some excellent durability, and are easy to seal in higher temperatures. But metal valve covers are generally more expensive and more difficult to install than most other materials.
How to Diagnose a Faulty Valve Cover Gasket
To determine if your valve cover gasket is faulty, you can follow these steps:
- Visual Inspection: Check for visible oil leaks around the valve cover. Look for oil spots on the engine or underneath your vehicle.
- Smell Test: Pay attention to any burning oil smells coming from the engine bay. Don’t ignore how much hp does a cold air intake.
- Engine Performance Check: Notice any unusual engine behavior, such as rough idling or misfires. These can indicate oil-related issues.
- Check Engine Light: If the check engine light is on or in the case of the Ford F150 Wrench Light On, it’s worth getting the vehicle scanned for trouble codes that may point to a gasket issue.
How to Fix Valve Cover Leak – step-by-step guides
A leaking valve cover gasket can cause you a lot if you don’t fix it. Don’t worry. I’ll explain how to fix a valve cover gasket leak in simple terms. That said, let’s quickly look at the valve cover gasket quick-fix method.
Tools Needed:
- Flathead screwdriver clean rag
- Wrenches or socket set
- Smooth sandpaper or gasket scraper
- A clean rag
Parts Needed:
- Gasket sealant
- New gasket
Step 1: Park your car.
Park your car on level, hard ground, and engage your hand brakes.
Step 2: Allow the engine to cool.
Open the hood and wait for the engine to cool so it won’t burn your hand.
Step 3: Unplug/disconnect the connection.
Unplug the ignition coil wires by depressing the lock tabs and pulling out the ignition coil’s wire socket.
Step 4: Unbolt the fastening bolts.
Use proper mechanic tools like ratchets and wrench sockets to Unbolt the ignition coil fastening bolts.
Step 5: Take off the ignition coils.
Gently take off the ignition coil by pulling them off the valve cover.
Note: you may have to slightly twist the coil to pull it off if it’s proving stubborn to come out.
Step 6: Unbolt the valve cover fasten the bolts.
Use appropriate mechanic tools like wrench sockets to Unbolt all the valve cover fastening bolts.
Step 7: Gently pull off the valve cover.
Pull off the valve cover from the head cylinder by slightly shaking the valve cover sideways or use a flat screwdriver to pry it off.
Step 8: Clean the valve cover.
Use your gasket scraper and clean the valve cover. Ensure you remove any gasket debris on the surface. Clean the head cylinder and make there is no leftover gasket debris on it.
Spray your brake cleaner to keep the surface free from oil residue.
Step 9: Install the gasket on the valve cover.
Carefully install the spark plug seals and the new valve cover gasket and back on the valve cover.
Step 10: Apply instant sealant.
Add a slight instant sealant on the valve cover where it seals with the cylinder head.
Step 11: Mount the valve cover.
Mount the valve cover on the head cylinder and drive the bolts with your hand until they catch the thread.
Step 12: Tighten the valve cover bolts.
Tighten the valve cover bolts to the manufacturer’s specifications with your torque wrench.
Step 13: Fix back the ignition coils to their position.
Fix back ignition coils back on the spark plug tubes just the same way you removed them.
- Note: If there is oil contamination on the coils, you have to replace the coil boots.
Step 14: Tighten the Coil fastening bolts.
Place back the ignition coil fastening bolts and run them with your hand until they catch the thread, use your torque wrench and tighten the bolts to the manufacturer’s specifications.
Step 15: Reinstall the electrical wires.
Plug back the spark plug sockets on the plugs by pressing them into the plug heads until you hear a locking sound.
Step 16: Check the engine oil level.
Gauge the oil level. If it’s below the standard gauge, add more oil.
Step 17: Start the car and inspect the valve cover.
Start your car and allow it to idle for some time. Check for any oil leaks in the valve cover.
What Is The Average Cost Of Replacing A Valve Cover Gasket?
Expect the valve cover gasket replacement cost to be between $90 and $400, depending on what type of vehicle you drive.
You will find new valve cover gaskets for $40 to $50, with the majority of the cost spent on labor. To replace the valve cover gasket, labor could be $50 to $350.
Thankfully, it’s often just the gasket that needs to be replaced and not the valve cover. However, if this part also needs to be replaced, it can be done with minimal effort at the same time you swap out the gasket, since both parts are removed at the same time.
The only additional charge would be for the valve cover itself.
How to Prevent Valve Cover Gasket Issues
- Regular Maintenance: Inspect gaskets during routine oil changes to identify wear early.
- Use Quality Oil: High-quality oil reduces sludge buildup that can degrade gaskets over time.
- Monitor Oil Levels: Frequent drops in oil levels can signal leaks.
- Address Warning Lights: Never ignore the check engine light, as it may indicate valve cover gasket issues. You can reset the check engine light with our guide.
FAQs.
Q: Can you drive a car with valve cover leaks?
Yes, you can drive a car with a valve cover leaks in as much as the number of oil leaks from the valve cover gasket is small, and the oil is not dripping on hot engine parts like the exhaust manifold or pipes.
If this is the case, it is relatively safe to drive your car until you have a chance to visit a mechanic garage or fix it yourself.
Q: Is a valve cover gasket leak serious?
Is valve cover leak serious? When the valve cover gasket shrinks over time due to the engine’s high temperature, the gasket will lose it’s value and leak, commonly causing oil leak issues, reduced engine performance, or drivability issues.
If not fixed on time, a valve cover gasket leak can cause severe engine breakdown.
Q: When should a valve cover gasket be replaced?
Because the valve cover gasket is made of rubbers, under excess heat from the engine, and over time, the gasket tends to shrink and becomes brittle, which is the most common cause of oil leaks around the valve cover.
When should you replace it? The valve cover gasket does not have any maintenance requirements. It should only be shrinks or leaks. However, the valve cover gasket is often replaced when doing major engine maintenance.
Q: How long can you drive with an oil leak?
It is always good not to run your car if it has an oil leak. However, a short distance drive within the city, less than 15 miles is not dangerous as driving with an oil leak until it lowers your oil level. In a nutshell, if the oil leak is much, do not drive the car at all.
Q: Can a valve cover gasket leak cause smoke?
As oil leaks from the valve cover gasket, the oil will end up running down till it gets on the exhaust manifold or pipes.
As the engine gets hot while idling or running the car, the exhaust will get hot and the oil. As soon as this happens, you’ll see white smoke coming from under your hood.
Final word
Whether the first symptoms of a valve cover gasket leak you notice is an ignition misfire, a puddle of oil on the floor, the smell of burning oil, or a low engine oil level, you have to replace the valve cover gasket once you find out that it’s leaking.
In some rear cases, it could be that the valve cover is not well-tighten, so tightening it may stop the leak. But typically, once the oil starts dripping out, you need to loosen the valve cover and add instant sealant to the gasket or replace it if it’s long gone.
Fixing small oil leaks before it gets spread over other components can help you diagnose other future oil leaks on your engine.