Don’t Let Your Engine Run Low On Oil – It Can Cause Serious Engine Damage
Can you smell burning oil coming from your car? Is it running rough, or does it have a rough idle? Have you noticed the oil levels are low when checking the dipstick? Any of these could be signs of an oil leak. You may be convinced you have an oil leak, but where is the oil leaking from? Usually, you’ll find spots of oil under your car when it’s parked on the street or driveway. The location of that oil spot is often the first indication of what is leaking under the hood. Any leaks near the front or center of the engine are likely a valve cover leak. If you’re convinced you have a valve cover gasket oil leak, let’s learn more and find out.
How Do I Know If My Valve Cover Gasket Is Leaking?
Your valve cover gasket prevents oil from leaking out of the valve cover. The valve cover itself protects the valve train components and keeps them lubricated. Both of these parts are located at the top of the engine cylinder head. You might notice a sticky ring of debris around the seal of the valve cover gasket. Debris around your gasket is a safe bet that it’s leaking.
Why is my valve cover gasket leaking?
Valve cover gaskets are usually made from either plastic, rubber, or cork, which helps the gasket maintain a tight seal. The seals are further reinforced with heat-tolerant caulk-like sealant called “gasket sealant”. This sealant isn’t invincible; over the years of use, heat, vibration, oil build-up, and debris cause the seal’s materials to deteriorate. As it breaks down, oil pressure causes oil to seep between the gasket and the cover, resulting in the previously mentioned “sticky ring” residue.
What are other signs of an oil leak?
Your Engine Oil is Low
Checking your engine oil on a regular basis lets you keep tabs on your vehicle’s health. If you notice low oil, it could be one of the first signs of a leak.
Your Engine Is Running Rough or Misfiring
The valve cover usually curves around your spark plugs. A leaking valve cover gasket sometimes causes oil to drip down and around the plugs, affecting spark and causing your engine to run roughly, idle roughly, or even misfire.
The Smell of Burning Oil
Valve covers are usually found at the very top of the engine. This places it above the hottest parts under the hood, including the exhaust manifold. A valve cover leak can drip onto these hot components, creating smoke and a smell like burnt oil. Heavier leaks may cause the oil to catch fire, so fix any leaks quickly to prevent fire hazards.
Pressure Build Up in the Valve Cover
Your PCV valve relieves pressure from the valve cover. If that valve becomes clogged, the buildup of pressure can cause the valve cover gasket, the component’s weak point, to fail. Oil will then start to leak from the valve cover.
It’s time to diagnose and fix a bad valve cover gasket
Locate the seam of the valve cover
Some vehicles will include a plastic shield covering the top of the engine. If your car or truck has this covering, remove and inspect the area where the valve cover meets the top of the engine. If you notice any oil leaks here, you can trace them back to the source.
Remove the valve cover
Assuming the issue is a bad valve cover gasket, you will have to remove the valve cover from the cylinder head. There will be several bolts around the outside of the valve cover. After removing these bolts, keep them in a safe place, so you don’t lose them or accidentally drop them inside the engine. Later vehicle models place the ignition coils on top of the spark plugs. If that’s the case, remove these before taking off the valve cover. Spark plugs do not need to be removed.
Mechanic’s note: Four-cylinder engines are typically easier than 6 and 8 cylinders, depending on the year, make, and model, of course, but in some cases, you may need to remove an air intake system. This may sound daunting, but it is usually a simple task. Overall, replacing a valve cover gasket isn’t a very difficult job when compared to some other mechanical tasks.
Check your PCV valve
Sometimes simply replacing your valve cover gasket isn’t enough. Inspect your PCV valve for clogs or dirt, too. If it’s clogged or dirty, replace it, because it could be the cause of your issues. PCV valves vary between different years, makes, and models, so check your owner’s guide or search Google for a proper replacement guide.
Replacing the valve cover
Clean the surface where the gasket goes onto, on both the cylinder head and the gasket cover. Then, squeeze a small bead of sealant onto the surface of the cylinder head and the valve gasket cover. Place the gasket on the cylinder head, matching the shape and bolt patterns. You can then replace the cover and bolt it down.
Mechanic’s Note: When seating any sealed item like a valve cover gasket, it is best to tighten every other bolt a few turns each to ensure they are all tightened evenly. If you tighten one all the down and then the next, the last bolts may not be as tight or seated as the first, which could cause the gasket to fail sooner than it should.
Reinstall the coil packs and any hoses you removed.
Clean remaining oil from the engine
You can use brake parts cleaner or engine degreaser to mop up any excess oil around the valve cover, cylinder head, oil fill cap, or anywhere else you see a mess. Clean engine parts will stop the oil-burning smell and help you identify new oil leaks quickly.