Valve Guides

WARNING: This page is about a different car, the 2002 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

Using a valve guide bushing brush and cleaning solvent, clean inside diameter of all valve guides. Ensure valve guide inside diameter is within specification. See CYLINDER HEAD table under ENGINE SPECIFICATIONS. Replace valve guide if inside diameter exceeds specification.
To replace valve guide, submerge cylinder head in a suitable container filled with water, and heat to 176-212°F (80-100°C). When cylinder head has reached specified temperature, remove and place on bench. Using a hammer, Valve Guide Remover/Installer (09201-1000) and Handle (09951-07100), drive out valve guide from camshaft (upper) side of cylinder head.
Using a caliper gauge, measure inside diameter of cylinder head valve guide bushing bore. If inside diameter is .4049-.4057 in. (10.285-10.306 mm), use standard valve guide.
If inside diameter of bore exceeds .4057 in. (10.306 mm), machine valve guide bushing bore to .4069-.4077 in. (10.335-10.356 mm) for oversize valve guide. Replace cylinder head if inside diameter of bore exceeds .4077 in. (10.356 mm).
CAUTION: Exhaust valve guide is 1.594 in. (40.5 mm) long and intake valve guide is 1.358 in. (34.5 mm) long. Ensure proper length valve guide is installed in the correct location.
To install valve guide, submerge cylinder head in a suitable container filled with water and heat to 176-212°F (80-100°C). When cylinder head has reached specified temperature, remove and place on bench. Using a hammer, Valve Guide Remover/Installer (09201-1000) and Handle (09951-07100), drive valve guide in from camshaft (upper) side of cylinder head, until valve guide protrudes .362-.386 in. (9.2-9.8 mm) for intake or .323-.346 in. (8.2-8.8 mm) for exhaust, above spring seat.
Using a sharp 5.5-mm reamer, ream valve guide to obtain standard valve stem-to-guide oil clearance. See CYLINDER HEAD table under ENGINE SPECIFICATIONS.