Removal and installation of the Mazda 3 cylinder head

Loosen the camshaft sprocket mounting bolts (camshaft timing mechanism mounting bolt) as shown in Figure 2.

Fig. 1. Components of the cylinder head disassembly stage: 1 - camshaft sprocket mounting bolts; 2 - camshaft sprockets; 3 - control oil valve (OCV) (L3); 4 - camshaft covers; 5 - camshafts; 6 - valve pusher; 7 – a bolt of fastening of a head of the block of cylinders; 8 – a head of the block of cylinders; 9 – laying of a head of the block of cylinders; 10 - cylinder block

Remove the camshaft sprockets.

Fig. 2. Loosening the camshaft sprocket bolts

Variable valve timing actuator (L3 with variable valve timing mechanism).

Remove the oil control valve (OCV) (L3 with variable valve timing).

Fig. 3. The sequence of loosening the camshaft bearing cap bolts

Remove the camshaft bearing caps by loosening the mounting bolts in three steps in the order shown in Figure 3.

Before removing the camshaft bearing caps, check the camshaft end play and the clearances in the camshaft bearings.

Camshaft bearing caps are numbered to ensure correct reassembly.

Once removed, keep the covers together with the cylinder head from which they were removed. Do not mix caps.

Remove the camshafts.

Remove the valve lifters.

Valve lifters are numbered to ensure correct reassembly.

After removal, keep the valve lifters together with the cylinder head from which they were removed. Do not mix valve lifters.

Fig. 4. Cylinder head bolt loosening sequence

Loosen the cylinder head bolts in two or three steps in the order shown in Figure 4.

Installing the cylinder head

Install the cylinder head.

Fig. 5. The order of tightening the cylinder head bolts

Tighten the cylinder head bolts in the order shown in Figure 5 in six steps.

  • 1.Tighten to 5.0 Nm
  • 2.Tighten to 13-17 Nm
  • 3.Tighten to 44-46 Nm
  • 4.Tighten 88-92°.
  • 5.Tighten 88-92°.
  • 6.Tighten completely.

Installing camshafts

Install the camshafts with the #1 cylinder piston at TDC on the compression stroke.

Fig. 6. Tightening order for the camshaft bearing cap bolts

Tighten the camshaft bearing cap bolts in two steps (fig. 6).

  • 1.Tighten to 5.0 - 9.0 Nm
  • 2.Tighten to 14.0-17.0 Nm

Assembly instructions for camshaft sprocket, variable valve timing actuator (L3 with variable valve timing).

Camshaft sprocket bolt or variable valve timing actuator (L3 with variable valve timing mechanism) is temporarily screwed in by hand until the timing chain is installed.

Fig. 7. Tightening the bolt for the camshaft sprocket (conventional engine) and the variable valve timing actuator

Camshaft sprocket or timing actuator connecting bolt valve timing (L3 with a mechanism for changing the valve timing) after installing the drive chain of the gas distribution mechanism is installed on the adhesive (Fig. 7). Tightening torque: 69–75 Nm.