Q45t V8-4130cc 4.1L DOHC MFI (VH41) (1997)
Valve Guide: Testing and Inspection
1. Measure valve deflection in a parallel direction with rocker arm. (Valve and valve guide mostly wear in this direction.) The valve deflection limit
(dial gauge reading) for both intake & exhaust is 0.15 mm (0.0059 inch).
2. If it exceeds the limit, check valve to valve guide clearance.
a. Measure valve stem diameter and valve guide inner diameter.
b. Check that clearance is within specification. Standard valve to valve guide clearance is as follows:
Intake: 0.029 - 0.052 mm (0.0011 - 0.0020 inch)
Exhaust: 0.035 - 0.051 mm (0.0014 - 0.0020 inch)
c. The limit is:
Intake: 0.086 mm (0.0034 inch)
Exhaust: 0.092 mm (0.0036 inch)
d. If it exceeds the limit, replace valve or valve guide.