Valve Cover Gasket Leaks – Function – Failure – Warning Signs

Valve Cover Gasket Leaks - Function - Failure - Warning Signs
Valve Cover Gasket Leaks - Function - Failure - Warning Signs

Stopping valve cover gasket leaks, between the valve cover and the cylinder head, is very important, for many reasons.

That’s why, the valve cover gasket needs to do it’s job, without any flaws.

So, to stop valve cover gasket leaks, most valve cover gaskets are made from, molded rubber.

Valve cover gasket leaks, are more common than you think. And, unlike the old days it’s not just oil you should be concerned about.

Today, the valve cover gasket has several important functions:

  • It protects cylinder head parts from the elements
  • Stops important lubricating oil from leaking externally
  • Controlling air leaks to help promote proper (PCV) operation

So, the valve cover gasket is very delicate and prone to oil leaks. Consequently, over time, it becomes brittle and will crack, due to exposure to dirt, debris, heat and other elements. When this occurs, it can lose its integrity and leak. Therefore, if not replaced in time, it can lead to complete engine failure.

Finding Valve Cover Gasket Leaks, Is Easier Than You Think

Luckily valve cover gasket leaks can be, pretty easy to diagnose. Firstly, the valve cover gasket is almost always, the highest seal in the engine.

Valve Cover Gasket Leaks
Valve Cover Gasket Leaks

If a vehicle’s oil is not changed often enough, sludge develops; clogging the drainage holes and placing a lot of pressure on the gasket. So, when the gasket is unable to function properly, oil leaks often occur.

Always Start With A Visual Inspection:

  • Loose or missing bolts or screws
  • Cracks in the valve cover
  • Part of the gasket sticking out, from under the valve cover
  • Evidence of a leak in the form of oil or black residue, around the edge of the valve cover
Valve Cover Gasket Leaks
Valve Cover Gasket Leaks

Most importantly, once you’ve confirmed you have a leak, you need to decide how to move forward.

If you have a missing bolt or screw, it should be replaced immediately. Make sure to torque the bolts, to the factory recommended torque. Consequently, if you tighten them too much; you can risk breaking the valve cover, and too loose, they can leak.

Common Warning Signs, Of A Failing Valve Cover Gasket:

The Smell Of Burning Oil

While the engine is running, the excess oil will drip on other components. These are all hot components that will burn the oil and produce; a burning oil smell that is easily recognizable.

Valve Cover Is “Caked” With Dirt And Is Leaking Oil

The quickest indication of this problem is when, the valve cover/cylinder head is very dirty. Because, oil attracts dirt and will appear to be “caked” on where its leaking.

Oil "Caked" On Where Its Leaking
Oil “Caked” On Where Its Leaking

So, if you look under your hood and discover that the valve cover is dirty; it’s most likely a leaking gasket.

Oil Level Is Low

Any oil leak, reduces the amount of oil in the oil pan. And, if this happens frequently, it can cause the engine oil light to appear on your dashboard. Furthermore, if the engine oil is low, it will reduce its ability, to properly lubricate internal engine components. Above all, this can build up excessive heat inside the engine and cause serious engine damage.

Engine Is Misfiring

IMPORTANT NOTE – Sometimes oil can leak all the way down to the spark plug and eventually; seep inside the spark plug tubes.

Oil Leaking Into Spark Plug Well
Oil Leaking Into Spark Plug Well

This will cause a misfire or reduce engine performance. Even worse, it can also cause a fire under your hood if it goes unrepaired.


So, proper, regular maintenance and routine oil changes, can help reduce the problems outlined above. As a result, helping you avoid further damage to primary engine components; essentially preventing damage and leaks, before they happen.

Thank You !