Valve Cover Gasket Vs. Head Gasket- Everything You Need To Know

There are many various types of gaskets and seals that can hang out and cause problems with car parts. The head gasket and the valve cover gasket are the most commonly replaced gaskets. 

So, what is the difference between these two? Are they both the same? What are they good for? This blog post will compare the head gasket and valve cover gasket and common leak symptoms for each.

Table of Contents

• Valve Cover Gasket Vs. Head Gasket
  • What is a head gasket?
  • What is a valve cover gasket?
  • Are they both the same? 
• Leaking Head gasket symptoms 
  • Contaminated Engine Oil
  • Rough Idle or Knocking Engine
  • Low Coolant Level
  • White Smoke Coming Out of Tailpipe
  • Engine Overheating
• Leaking Valve Cover Gasket Symptoms
  • Visible oil leaks and a dirty valve cover
  • Low Engine Oil Level
  • The smell of burning oil
  • Misfire and Rough Idling of the Engine
  • Warning lights on the dashboard
  • Smoke from the engine compartment
• What Happens When The Valve Cover Gasket Is Blown?
• How to check for valve gasket and head gasket leaks?
  • How to Recognize a Leaking Head Gasket?
  • How to Recognize a Valve Cover Gasket Leak?
  • What’s the difference between a leaking head gasket and a leaking valve cover gasket?
• Some related FAQs.

Valve Cover Gasket Vs. Head Gasket

What is a head gasket?

A car engine’s head gasket is a seal between the engine block and the cylinder head. The head gasket’s main function is to seal the cylinders, ensuring optimal compression and avoiding coolant and oil leaks. 

What is a valve cover gasket?

The valve cover is sealed to the top of the engine cylinder head by a valve cover gasket. The gasket keeps oil from leaking as the camshafts, rockers, and valves move around. The valve cover gasket also seals off many of the spark plug ports.

Are they both the same?

No, a head gasket is different from a valve cover gasket. They are manufactured in different materials and are used for different purposes. Most head gaskets are made of metal or a combination of metal and plastic. In contrast, valve cover gaskets are usually made of rubber or silicone. 

While valve cover gaskets are between the engine’s valve cover and cylinder head, head gaskets are between the engine block and cylinder head.

How Long Do Head Gaskets Last?

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Leaking Head gasket symptoms 

Here are some common symptoms of a leaking head gasket.

Contaminated Engine Oil

We all know that oil and water don’t mix, but if your engine’s coolant gets into the oil, the mixture loses its lubricating properties. When the head gasket leaks, engine coolant can enter the oil system. The result is a thick, foamy mixture that can build up under the oil filler cap on the engine.

Rough Idle or Knocking Engine

If the head gasket leaks badly enough, the engine won’t be able to make enough power. This can cause the engine to idle badly, knock, or even stop running.

But other things can make the engine run rough or knock. If you get support from a technician, he may do a compression leak test on your car to find out if it has a leaking head gasket. If combustion gasses mix with the engine oil, your head gasket may have failed internally.

Low Coolant Level

If the car’s head gasket fails between a coolant channel and one of the combustion chambers in your engine, the engine may start to use up coolant. This can also cause the engine to overheat because there isn’t enough coolant.

White Smoke Coming Out of Tailpipe

Most of the coolant in an engine is water, and when the coolant is burned, white smoke can be seen coming out of the tailpipe. This is an indication that the engine is consuming coolant as a result of a leaking head gasket.

Suppose coolant isn’t used up in the engine, but the coolant level is always low. In that case, you may need to look for a leak somewhere else in the cooling system or where the engine block meets the cylinder head on the outside.

Engine Overheating

One of the most common symptoms of your car’s head gasket failing is the engine getting too hot. If the head gasket doesn’t work, the engine must work harder to produce power.

Also, a blown head gasket can cause your car to lose coolant, making the engine cooling system less effective and worsening the overheating problem.

Leaking Valve Cover Gasket Symptoms

When you first notice that a valve cover leaks, you still have time to fix the problem before it worsens. Here are some signs that your valve cover gasket is leaking, which can help you determine where the leak is coming from.

Visible oil leaks and a dirty valve cover

Most auto mechanics will look at your valve cover when they change your oil. The valve check is done to see if your valve cover gasket has any leaks.

If you look under your car’s hood and see that the valves are dirty, your valve cover is likely leaking, and you need a new valve cover gasket.

Low Engine Oil Level

You must know that an engine oil leak would result from a damaged valve cover. Your oil pan is full of oil because the valve cover gasket is broken.

If this keeps happening for a long time, the engine oil light on your dashboard indicates that the engine needs more oil.

The smell of burning oil

Oil leaks from the cylinder head and under the valve cover when a gasket gets worn, brittle, or cracked.

Suppose this happens while your engine is idling. In that case, the oil leaks onto parts of the engine like the cylinder head, the fuel intake, and sometimes the exhaust manifolds and pipes.

If you smell burned oil, you should check your car for oil leaks or call a mechanic to find and fix the problem.

Misfire and Rough Idling of the Engine

In some car makes and models, the valve cover acts as a seal to prevent oil from leaking into the spark plug. Most of these seals are in the shape of O-rings.

When the gasket breaks, engine oil leaks into the spark plug tubes because of how hot the engine is.

Warning lights on the dashboard

If you haven’t been changing your engine oil often, dashboard warning lights could be the first sign that something is wrong.

Your ‘Oil Warning Light‘ may indicate a lack of oil pressure in your vehicle, or it may illuminate the ‘Check Engine Light’ due to flaws caused by a cracked gasket and valve cover.

Smoke from the engine compartment

When engine oil leaks from the valve cover gasket and runs down the exhaust manifold and other hot engine parts, smoke may come out of your engine compartment.

What Happens When The Valve Cover Gasket Is Blown?

Running your car for an extended period without inspection and repair if your engine loses oil can result in permanent damage. If the gasket is worn out, it will leak engine oil, which will likely cover the top of the engine. It can also let dirt, debris, and other pollutants into your engine, which can cause long-term damage.

You’ll need to get a new one right away to keep your engine from getting seriously damaged. When your mechanic changes the valve cover gasket, ask them to check the valve cover as well.

How to check for valve gasket and head gasket leaks?

How to Recognize a Leaking Head Gasket?

Mechanics can determine what’s wrong with a leaking head gasket in several ways. One way to check for leaks in the gasket is to do a compression test. Another is to perform a “dye test,” which entails mixing a special dye with the coolant and using a blacklight to search for leaks.

Once the mechanic has found out what’s wrong, they can start fixing it. The head gasket can sometimes be changed. Sometimes, the engine may need more extensive repairs.

How to Recognize a Valve Cover Gasket Leak?

You can do a few easy tests at home to find out if your car is leaking oil. First, use the dipstick to check the oil level. If it’s low, it could mean that there’s a leak.

Next, look at your engine’s spark plugs. If they are covered in oil, that’s another sign that oil is getting into the combustion chamber.

What’s the difference between a leaking head gasket and a leaking valve cover gasket?

The place of the leak origin is the most obvious difference. A head gasket leak will be between the cylinder head and the engine block. A gasket leak will be between the cylinder head and the valve cover.

What kind of fluids are leaking is another important difference. Oil and coolant can mix and leak out when the head gasket leaks. This can cause all sorts of problems with the engine, like overheating and not getting enough oil.

If the gasket on the valve cover is broken, only oil will leak out. Even though this isn’t as bad as a leaking head gasket, it can still damage the engine if it’s not fixed.

Lastly, the signs of a leaking head gasket and a leaking valve cover gasket can be very different. When the head gasket leaks, the engine often overheats. When the valve cover gasket leaks, however, the engine usually just leaks oil.

If you don’t know what kind of leak your car has, you should take it to a mechanic and have them figure out what’s wrong. They can determine what’s happening and advise you on what to do next.

The most typical types of leaks in cars are head gasket leaks and valve cover gasket leaks. Both can hurt the engine a lot if they aren’t fixed. Still, there are some important similarities and differences between them. You can identify both leaks by doing a simple and quick checkup. If you can’t determine it, you must contact a technician to fix the issue before it harms the vehicle further. 

Some related FAQs.

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