The following procedures are provided as an overview for guide replacement. After the guides have been replaced the valve to valve seat contact area must be check. It may be necessary to match ground to the valves to the seats. All valve and valve seat grinding operations should be performed by a qualified machine shop; only the valve lapping operation is recommended to be performed by the home mechanic.
REMOVAL & INSTALLATION
See Figures 1, 2, 3 and 4
- Using a 2-ton press or a hammer and a suitable driving tool, drive the old valve guide from the cylinder head, in the rocker cover to combustion chamber direction.
Heating the cylinder head to 302-392°F (150-200°C) will facilitate the operation.
- Using the Valve Guide Reamer tool KV11081000 (F10) or ST11081000 (all other models, ream the valve guide hole.
- Using a new valve guide, press it into the cylinder head and ream the guide hole with the proper size reamer.
- Using a valve seating tool kit, cut a new valve contact on the valve seat.
- To install the removed components, reverse the removal procedures.
See Figure 5
Valve guides which are not excessively worn or distorted may in some cases, be knurled rather than reamed. Knurling is a process in which metal inside the valve guide bores is displaced and raised (forming a very fine crosshatch pattern), thereby reducing clearance. Knurling also provides for excellent oil control. The possibility of knurling rather than reaming the guides should be discussed with a machinist. Most Nissan models covered in this information have replaceable valve guides.