Why is My Valve Cover Gasket Leaking?

Valve Cover Gasket

Your valve cover gasket may be leaking for a variety of reasons.  It could be shrunken, cracked or rotten, or your valve cover itself may be cracked or broken or one of the valve cover bolts may just be loose, allowing a little leak.

Your car may have 1 or 2 valve covers depending on its configuration.  A straight 4 or 6 cylinder engine will have 1 valve cover, while “V” configured engines like a V6 or V8 will have 2 valve covers, one on each side.  The valve cover sits on top of the cylinder head and does just what its name suggests, covers the valves.  The valves in your engine are opened and closed either by a rocker arm that is moved either directly by the camshaft lobs, or by pushrods that ride on the cam shaft lobs.  The valves, rockers and pushrods or camshaft all need to be lubricated with engine oil to stay cool and not wear out.  The oil pump draws oil out of the oil pan and pushes it through the oil filter, then up into the engine head where it can lubricate all the moving components and then it drains through small holes back into the oil pan through the block.

This means that there should not be any high-pressure oil around the valves, simply oil flowing around them.  The lack of high-pressure oil under the valve cover gasket means that most valve cover gasket leaks will be very slow, or more of a weep rather than a stream or a squirt.  This can make them difficult to diagnose as there will be less evidence of the leak.  Even though they can be slower leaks, fixing a valve cover gasket leak quickly is important for a few reasons.  First, the oil can leak onto the exhaust manifold causing fumes and the possibility of a fire.  Also, a slow leak can still deplete your engine oil quickly, causing premature wear or even catastrophic damage to your engine.

How to identify a valve cover gasket leak

Valve cover gasket leak www siennachat comFirst, let’s make sure you actually have a leak coming from your valve cover gasket.  Nothing is more frustrating than putting a lot of time and energy into solving a problem, only to find out all that work was for nothing and your problem was actually something else.  Luckily valve cover gaskets can usually be pretty easy to diagnose.  The valve cover gasket is almost always the highest seal in the engine.  Your job is to find the evidence of the leak, or dripping oil and follow the drip higher and higher on the engine until it disappears.  This can be pretty easy if it is on the front or side of the engine, but if the leak is in the back near the firewall it can be difficult to do without a flashlight and a mirror.  The best way to check for a valve cover leak is to move enough things out of the way that you can check the whole perimeter of the valve cover from the top side.  This may involve removing spark plug wires, throttle linkages or even the intake manifold.

Once you have the entire perimeter of the valve cover gasket visible, you need to check for a few things:

Valve cover inspection:

  1. Loose or missing bolts or screws
  2. Cracks in the valve cover
  3. Part of the gasket sticking out from under the valve cover
  4. Evidence of a leak in the form of oil or black residue around the edge of the valve cover.

Once you’ve proved you have a valve cover gasket or another type of oil leak (if so, you may want to look at an oil leak sealant), you need to decide how to move forward.  If you have a missing bolt or screw, it should be replaced immediately.  The easiest way to do that is to remove a second bolt and take it to your local hardware store and ask them to match it.  When replacing both, make sure to use a torque wrench to torque the bolts to the factory recommended setting.  If you tighten them too much, you can risk breaking the valve cover, and if too loose, they can fall out again or cause a leak.  If the valve cover is cracked or broken, get a replacement valve from the dealer, a junkyard, or even try eBay.

How to fix a valve cover gasket leak

If you find evidence of a leak, the best solution is to use BlueDevil Oil Stop Leak.  Adding 8oz. of BlueDevil oil stop leak to your engine oil is guaranteed to permanently seal any oil leaks in your vehicle’s engine.  BlueDevil Oil Stop Leak is not a petroleum distillate like other stop leak products on the market today.  That means BlueDevil Oil Stop Leak can act as a valve cover gasket sealer and stay in your engine oil until your next oil change and will not clog or harm your engine in any way.  BlueDevil Oil Stop Leak will restore dried, cracked or shrunken seals to original size and shape, allowing them to reseal and stop your leak.

BlueDevil Oil Stop Leak

Pick Up BlueDevil Oil Stop Leak today at any of BlueDevil’s partnering auto parts stores:

  • O’Reilly Auto Parts
  • Pep Boys
  • CarQuest Auto parts
  • Bennett Auto Supply
  • NAPA
  • AutoZone
  • Prime Automotive Warehouse
  • Advance Auto Parts

You can also purchase BlueDevil Oil Stop Leak, and other BlueDevil products directly from BlueDevil online here: Oil Stop Leak

Pictures courtesy of: www.automedia.com and www.siennachat.com