Engine misfires paired with the sharp odor of burning oil are telltale signs of a failing valve cover gasket — and if yes, you’ll have to get it replaced.
Wondering how to do a gasket replacement?
Or how much it’ll cost to replace a valve cover gasket?
We’ll answer both those questions, highlight valve cover gasket leak symptoms, and examine possible causes. We’ll also explore how long a new gasket can last, and how to prevent leakages in the first place.
This Article Contains:
- What Is a Valve Cover Gasket?
- Is a Valve Cover Gasket Leak Serious?
- How to Replace a Leaky Valve Cover Gasket
- How Much Does a Valve Cover Gasket Replacement Cost?
- How Long Does a Valve Cover Gasket Last?
- What Are the Symptoms of a Bad Valve Cover Gasket?
- What Causes a Valve Cover Gasket to Fail?
- How to Prevent Valve Cover Gaskets From Leaking
What Is a Valve Cover Gasket?
The valve cover gasket sits between the valve cover and cylinder head, sealing the space so engine oil doesn’t leak out. Most gaskets are made from rubber, silicone, plastic, or cork.
A properly sealed gasket ensures your car has enough engine oil to lubricate essential parts such as the piston pins, crankshaft bearings, and valves.
However, constant heat exposure and engine debris can cause the gasket to develop a small leak, which can eventually contribute to a low oil level.
Is a Valve Cover Gasket Leak Serious?
Yes!
A small leak won’t cause immediate issues, but your car may run out of engine oil if not fixed.
Over time, oil seeping out can drip onto hot engine parts, creating smoke, odor, and even a potential fire hazard. In fact, a bad valve cover gasket can cause loss of power and accelerate wear on vital components, as the engine struggles with reduced lubrication and performance.
If left unresolved, a minor gasket issue can snowball into costly repairs or even a full engine replacement. That’s why you should call a mechanic and fix the valve cover gasket ASAP.
We’ll address valve cover gasket leak repair costs in a bit, but first, let’s find out what replacement involves.
How to Replace a Leaky Valve Cover Gasket
The mechanic will start by checking the oil pan for cracks or tightening the valve cover bolts with a torque wrench. But if the leak continues, they’ll replace the faulty gasket.
Here’s how they’ll do it:
- Allow the engine to cool off: The mechanic will switch off the car and let the engine cool down completely.
- Access the bad valve cover gasket: They’ll refer to the service manual to locate and access the bad gasket. Then, they’ll remove components such as the engine cover, PCV hoses, electrical connectors, and spark plug tubes (in older engines).
- Remove the valve cover: The mechanic will use a rubber mallet (a hammer-like object with a rubber head) to gently tap the valve cover and lift it off with their hands.
- Replace the old gasket with the new one: Next, the mechanic will remove the old unit and clean the spilled oil in the surrounding valve cover gasket area. Then, they’ll fit the new piece into its groove.
- Apply silicone to the new gasket: If your manufacturer recommends it, they’ll apply a silicone sealant to the gasket (otherwise, they’ll skip this step).
- Reinstall the valve cover: Finally, they’ll reinstall the PCV hoses, electrical connectors, bolts, spark plug tubes, and engine cover. Then, they’ll tighten each valve cover bolt using a torque wrench.
The mechanic will refer to the service manual for the recommended torque to ensure no bolt is over-tightened.
NOTE: While working with a rubber, cork, or silicone gasket, mechanics avoid using metal tools to prevent damage. So, while replacing the bad gasket, you’ll mostly notice them using their hands and a torque wrench to tighten the bolts.
Now, let’s find out what a valve cover gasket leak repair costs.
How Much Does a Valve Cover Gasket Replacement Cost?
On average, replacing a valve cover gasket costs around $110 to $380, depending on your vehicle’s make and model, the valve cover gasket price, and local labor rates.
This cost covers:
- New gasket: $10 to $80
- Labor: $100 to $300
The next important question is:
How Long Does a Valve Cover Gasket Last?
A valve cover gasket can last for around 20,000 to 50,000 miles, though it may last much longer if the gasket material is high-quality and oil changes are timely (dirty oil circulates heat poorly, baking the gasket more than necessary).
Which raises the question:
What Are the Symptoms of a Bad Valve Cover Gasket?
Here are a few telltale signs of a faulty valve cover gasket:
- Low engine oil: A car with a gasket leak won’t have enough oil for lubrication, increasing friction amongst the engine block parts. Gradually, your vehicle will overheat and stop working altogether.
- Frequent oil changes: If you notice that you’ve been getting oil changes more often than needed, there might be a valve cover leak.
- Burning oil smell and smoke from the engine: When leaking oil spills over hot engine parts like the exhaust manifold, it heats up. After a while, you’ll notice a burning smell and smoke emitting from under the hood.
- Engine misfire: A valve cover oil leak can cause fluids to spill into the spark plug wells and soak the plugs, meaning the plugs won’t ignite properly. This can cause a loss of power along with engine misfires during acceleration.
- Rough-running engine: Without sufficient oil, the metal components will start rubbing against each other, creating friction. Eventually, the increased friction will overheat the engine, making it run rough.
- Oily and dirty valve cover: Normally, the valve cover gasket area is supposed to be clean. However, a failing gasket will leave oil residue that attracts dust and debris, forming a greasy buildup.
NOTE: An oil pan and valve cover leak can often look alike. So, if you notice oil leakage, call an auto repair mechanic to confirm whether the leak is coming from a worn gasket or the oil pan.
So, what makes this little seal throw in the towel?
Time to find out.
What Causes a Valve Cover Gasket to Fail?
The usual suspects behind a failing valve cover gasket are:
- Engine heat: Constant exposure to high temperatures dries out and hardens the gasket, making it brittle and prone to cracking.
- Irregular sealing surfaces: Dirt, corrosion, and warping on the valve cover or cylinder head prevent the gasket from sealing properly.
- Loose bolts on the cover: If the bolts aren’t snug enough, the gasket can’t stay compressed, allowing oil to seep out.
- Over-tightened hold-down bolts: Tightening too much can crush or deform the gasket, creating weak spots for leaks.
- Excessive internal engine pressure: Blocked positive crankcase ventilation valves (PCV) or ventilation issues can raise pressure inside the engine and push oil past the seal.
So if you’re wondering how to make your valve cover gasket last longer, keep reading.
How to Prevent Valve Cover Gaskets From Leaking
Here are a few measures you can take to ensure your valve covers last longer:
- Maintain your cooling system, as overheating can crack gaskets faster.
- Avoid aggressive driving and rapid acceleration, as excess heat and pressure can put more strain on the valve cover gasket.
- Purchase a good-quality valve cover gasket set that can withstand high engine temperatures and chemicals in the oil.
Also, keep the engine bay clean. Oil and debris buildup around the valve cover can hide leaks until they become severe — and you’ll want to notice a problem sooner rather than later.
Keep Valve Cover Gaskets Leak-Proof with AutoNation Mobile Service
Once the valve cover gasket cracks or wears, it’ll eventually start leaking. Ignoring these valve cover gasket symptoms can lead to severe engine damage.
But if dealing with gasket repairs seems overwhelming, mechanics from AutoNation Mobile Service can come to you and replace the faulty gasket right from your driveway. We’re a mobile auto repair solution that offers easy online bookings and upfront pricing. We also offer a 12-month, 12,000-mile warranty on all repairs.
Contact us, and let’s seal things up before your valve cover gasket loses its cool.