If the valve guides are determined to be worn during the valve inspection procedure, there are two possible repair alternatives, knurling or replacement. Either procedure can be done by a competent automotive machine shop.
If guide wear is minimal, the correct inside diameter can be restored by knurling. Knurling involves using a special tool to raise a spiral ridge on the inside of the guide while it is installed in the head. This effectively reduces the inside diameter of the guide. A reamer is then usually passed through the guide to make the inside diameter smooth and uniform.
Knurling is only an alternative if there is minimum guide wear. Excessive wear can only be corrected by replacing the guide.
REMOVAL & INSTALLATION
- Gradually heat the disassembled cylinder head in water to approximately 190°F (90°C).
- Remove the cylinder head from the water and place it on a bench. Block the head on its side, or install a pair of head-holding brackets made especially for cylinder head service.
- Drive out the valve guide toward the camshaft side of the cylinder head using valve guide remover tool T87C-6510-A or equivalent.
- Drive in the new guide using the same tool. Drive the guide in until 0.752-0.772 in. (19.1-19.6mm) of the guide protrudes from the top of the head.
The valve guide is an integral part of the cast iron cylinder head on the 3.0L engine. It can only be removed using a special cutter tool, usually mounted on a cylinder head machine. The new guide is then driven in and retained by press-fit.