See Figures 15, 16, 17 and 18

Disconnect the negative battery cable.

On the 1.2L and 2.5L engines, remove the intake manifold stay bracket from the engine.

Disconnect the vent hoses from the intake manifold and from the cover assembly.

Fig. 15: To remove the valve cover on V6 engines, detach the spark plug wires from the plugs, and if necessary, remove the intake manifold

Remove the spark plug wires from the spark plugs, make a note of plug wire original location.

On 2.3L engines and for rear valve cover removal on the 1.2L and 2.5L engines perform the following:

Remove the intake manifold assembly from the engine.

Fig. 16: Exploded view of the valve cover assemblies on the V6 engines

Remove the ventilation pipe attaching bolts and disconnect the pipe from the front cover.

Remove the cover bolts and remove the cover assembly.

To install:

Clean all old gasket material from the rocker arm cover and the cylinder head.

Install a new gasket onto the cover.

Apply silicone sealer to the cylinder head perimeter.

Fig. 17: Mazda V6 engines valve cover bolt tightening sequence for right-hand covers

Fig. 18: Mazda V6 engines valve cover bolt tightening sequence for left-hand covers

Install the cover assembly and the bolts and tighten in the sequence shown over three steps to 43-6 inch lbs. (4.3-2.2 Nm).

Install the ventilation pipe to the front cover assembly and tighten the bolts to 63-35 inch lbs. (1.2-5 Nm).

If removed, install a new gasket to the intake manifold assembly and install it to the engine. Loosely tighten the bolts and nuts.

On the 1.2L and 2.5L engines, install the intake manifold stay and tighten the bolts to 8-7 ft. lbs. (7-25 Nm).

If necessary, tighten the intake manifold nuts and bolts over three stages to the proper specification.

Connect the vent hoses and connect the negative battery cable.

Start the engine and inspect for leaks.