Valve Clearance Inspection

WARNING: This page is about a different car, the 2004 Mazda 3. However, it is still accessible from the selected car via links, so may be relevant.

Remove the plug hole plate. (See PLUG HOLE PLATE REMOVAL/INSTALLATION .)
Remove the battery cover.
Disconnect the negative battery cable.
Disconnect the wiring harness.
Remove the ignition coils. (See IGNITION COIL REMOVAL/INSTALLATION .)
Disconnect the OCV connector (L3).
Remove the ventilation hose.
Remove the cylinder head cover.
Verify that the engine is cold.
Measure the valve clearance.
1. Turn the crankshaft clockwise so that the No. 1 piston is at TDC of the compression stroke.
2. Measure the valve clearance at A in the figure.
  - If the valve clearance is out of the standard value, adjust it. (See VALVE CLEARANCE ADJUSTMENT .)
  Fig 1: Identifying Valve Clearance Measurement Locations
  Courtesy of MAZDA MOTORS CORP.
  
  Standard [Engine cold]
  
  IN: 0.22-0.28 mm {0.0087-0.0110 in}
  
  EX: 0.27-0.33 mm {0.0107-0.0129 in}
  NOTE:
  - Make sure to note down the measured values for choosing the suitable replacement tappets.
3. Turn the crankshaft 360° clockwise so that the No.4 piston is at TDC of the compression stroke.
4. Measure the valve clearance at B in the figure.
  - If the valve clearance is out of the standard value, adjust it. (See VALVE CLEARANCE ADJUSTMENT .)
NOTE:
- Make sure to note down the measured values for choosing the suitable replacement tappets.
Standard [Engine Cold]
1. IN: 0.22-0.28 mm {0.0087-0.0110 in}
2. EX: 0.27-0.33 mm {0.0107-0.0129 in}
Install the cylinder head cover. (See CYLINDER HEAD COVER INSTALLATION NOTE .)
Install the ventilation hose.
Connect the OCV connector (L3).
Install the ignition coils. (See IGNITION COIL REMOVAL/INSTALLATION .)
Connect the wiring harness.
Connect the negative battery cable.
Install the battery cover.
Install the plug hole plate and bracket. (See PLUG HOLE PLATE REMOVAL/INSTALLATION .)