Valve Guide: Testing and Inspection

Valve Guide Identification Measurement

- Tools Required
- J43120 Valve Guide Go/No-Go Gauge (7 mm)
- J43481 Valve Guide Go/No-Go Gauge (6 mm)

Saturn Valve Guide Go/No-Go Gauges (P/Ns J43120 and J43481) are precision tools that allow technicians to quickly and accurately measure cylinder head valve guide bores for proper diameter, roundness, and straightness. This type of tool is commonly used in manufacturing for qualifying bores, sleeves, guides, etc. Precision tools must be used and handled with care. Do not drop, bend, score,m scratch, or otherwise damage the gauge measuring pins or holder. Store the tools in a safe and secure location when not in use as described in the letter when accompanied the 7 mm tool in a previous mailing. Also, lightly coat the gauge measuring pins with oil or silicone lubricant to inhibit corrosion when in storage. If surface corrosion occurs clean the pins with fine steel wool.

Procedure:
1. With cylinder head removed from engine and valve removed from guide, thoroughly clean the valve guide using a drill driven guide brush and solvent.

NOTICE: The Go (Green) end of the gauge should go through the entire length of the guide with light and uniform pressure. Use of excessive force will result in tool damage.

2. Insert the Go (Green) end of the appropriate gauge (P/N J43120 or J43481) into the guide from either the combustion chamber side or the camshaft side:
- If the gauge passes through the gauge with light and uniform pressure, proceed to step 3.
- If the gauge will not pass through the guide with light and uniform force, clean the guide again as in step 1 and repeat the guide measurement. If the gauge still will not pass through the guide with light and uniform pressure, refer to the appropriate valve guide repair and/or replacement procedures.

NOTICE: The No-Go (Red) end of the gauge should not enter either end of the guide. Use of excessive force will result in tool damage.

3. Attempt to insert the No-Go (Red) end of the gauge into both ends of the valve guide:
- If the gauge does NOT enter either end of the gauge, the guide is within the correct specifications for diameter, straightness, and roundness.
- If the gauge enters wither end of the guide, the guide is oversized beyond specifications. Refer to the appropriate valve guide repair and/or replacement procedures.