If the gasket under the valve cover on your Mazda 626 is leaking, you will have to remove the valve cover to replace it. You may also need to remove the valve cover to access components inside the cover should valve train repair become necessary. The cover is made from cast aluminum and can be damaged easily, so work slowly and carefully to make sure you don't crack or break any part of the cover as you remove it.
Locate the vent hose on the front edge of the valve cover and pull it off the nipple on the cover. Lay the hose aside.
Grasp the PCV valve on top of the valve cover and pull it straight up and out of the grommet. Set the PCV valve aside.
Locate the retaining bolts around the perimeter of the cover. Remove all eight bolts with a socket and ratchet. Set the bolts aside.
Slide a stiff putty knife or other flat tool under the edge of the cover and break it loose from the cylinder head. Lift the cover off the head. If you car has the dual overhead cams, you will need to remove the spark plug wires before lifting the cover off, as they run through the top of the cover.
