Inspection After Disassembly

Cylinder Head Bolts Outer Diameter 

• Cylinder head bolts are tightened by plastic zone tightening method. Whenever the size difference between (B) and (A) exceeds the limit, replace them with new one.

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  Limit [(B) - (A) ]	: 0.18 mm (0.0071 in)
  (c)	: 55 mm (2.17 in)
  (d)	: 12 mm (0.47 in)

• If reduction of outer diameter appears in a position other than (A), use it as (A) point.

Cylinder Head Distortion 

1. Using a suitable tool, wipe out oil, scale, gasket, sealant and carbon deposits from surface of cylinder head.
   CAUTION: Do not allow gasket fragments to enter engine oil or engine coolant passages.
2. At each of several locations on bottom surface of cylinder head, measure the distortion in six locations

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   Limit

   : Refer to Cylinder Head .

• If it exceeds the limit, replace VVEL ladder assembly & cylinder head assembly.
  NOTE: Cylinder head assembly cannot be replaced as a single part, because it is machined together with VVEL ladder assembly.

Valve Dimensions 

• Check the dimensions of each valve. For the dimensions, refer to Cylinder Head .
• If dimensions are out of the standard.
  • Replace valve and check valve seat contact. Refer to "VALVE SEAT CONTACT".

Valve Guide Clearance 

Valve Stem Diameter

• Measure the diameter of valve stem with suitable tool (A).

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  Standard

  : Refer to Cylinder Head .

Valve Guide Inner Diameter

• Measure the inner diameter of valve guide with suitable tool.

  Standard

  : Refer to Cylinder Head .

Valve Guide Clearance

• (Valve guide clearance) = (Valve guide inner diameter) - (Valve stem diameter)

  Standard

  : Refer to Cylinder Head .

• If the calculated value exceeds the limit.
  • Replace valve (EXH) and/or valve guide (EXH). Refer to Exploded View . (Exhaust side)
  • Replace valve (INT) and/or VVEL ladder assembly & cylinder head assembly. Refer to Exploded View . (Intake side)
    NOTE: Since the valve guide (INT) cannot be replaced by the piece, VVEL ladder assembly & cylinder head assembly replacement are required.

Valve Seat Contact 

• After confirming that the dimensions of valve guides and valves are within the specifications, perform this procedure.
• Apply prussian blue (or white lead) onto contacting surface of valve seat to check the condition of the valve contact on the surface.
• Check if the contact area band is continuous all around the circumference.

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  (A)	: OK
  (B)	: NG

  • If not, grind to adjust valve fitting and check again. If the contacting surface still has "NG" conditions even after the re-check, replace valve seat. Refer to Exploded View .

Valve Spring (with valve spring seat) Squareness 

• Set a suitable tool (A) along the side of valve spring (with valve spring seat) and rotate spring. Measure the maximum clearance between the top of spring and try square.

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  (B)

  : Contact

  Limit

  : Refer to Cylinder Head .

• If it exceeds the limit.
  • Replace valve spring (with valve spring seat). Refer to Exploded View .

Valve Spring Dimensions and Valve Spring Pressure Load 

• Check the valve spring (with valve spring seat) pressure at specified spring height.

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  Standard

  : Refer to Cylinder Head .

• If the installation load or load with valve open is out of the standard.
  • Replace valve spring (with valve spring seat). Refer to Exploded View .

INSPECTION AFTER ASSEMBLY 

The following are procedures for checking fluid leakage, lubricant leakage.

• Before starting engine, check oil/fluid levels including engine coolant and engine oil. If any are less than the required quantity, fill them to the specified level. Refer to Fluids and Lubricants .
• Follow the procedure below to check for fuel leakage.
  • Turn ignition switch to the "ON" position (with engine stopped). With fuel pressure applied to fuel piping, check for fuel leakage at connection points.
  • Start engine. With engine speed increased, check again for fuel leakage at connection points.
• Run engine to check for unusual noise and vibration.
  NOTE: If hydraulic pressure inside chain tensioner drops after removal/installation, slack in guide may generate a pounding noise during and just after the engine start. However, this does not indicate a malfunction. The noise will stop after hydraulic pressure rises.
• Warm up engine thoroughly to check that there is no leakage of fuel, or any oil/fluids including engine oil and engine coolant.
• Bleed air from lines and hoses of applicable lines, such as in cooling system.
• After cooling down engine, again check oil/fluid levels including engine oil and engine coolant. Refill them to the specified level, if necessary.
  Summary of the inspection items:
  
  

  Items	Before starting engine	Engine running	After engine stopped
  Engine coolant	Level	Leakage	Level
  Engine oil	Level	Leakage	Level
  Transmission / transaxle fluid	Leakage	Level / Leakage	Leakage
  Other oils and fluids*	Level	Leakage	Level
  Fuel	Leakage	Leakage	Leakage

  * Power steering fluid, brake fluid, etc.