Using a valve grinder, resurface the valves according to specifications in this chapter.
NOTE: All machine work should be performed by a competent, professional machine shop. Valve face angle is not always identical to valve seat angle.
Reface the valves with a refacing tool, following the instructions of the tool manufacturer. See illustrations for dimensions and angles. Remove just enough metal to clean up faces and seats. If, during the refacing process, valve margin becomes less than 1mm (0.04 in.) the valve must be replaced. On the 1,998cc and 2,184cc engines, exhaust valve margin is 1mm (0.04 in.) but intake valve margin need be only 0.5mm (0.00197 in.) or more.
On the diesel, there is no margin limit, provided contact width can be brought to specification, which is 1.7–2.3mm (0.0669–0.0906 in.). To check margin width, apply a thin coating of red lead to the valve seat and then press the valve firmly against the seat without rotating it. Then, measure the width of the mark.