W 250 Pickup V8-360 5.9L VIN I (1987)
Positive Crankcase Ventilation: Service and Repair
On 1982-84 six and eight cylinder light duty emissions cycle vehicles, check system operation every 15,000 miles, and replace PCV valve every
30,000 miles. On four cylinder and all 1985-87 light duty cycle vehicles, replace PCV valve every 52,500 miles. On 1980-84 heavy duty cycle vehicles
and 1985-87 heavy duty cycle California vehicles and Federal vehicles with a single air pump, check system operation every 12,000 miles and replace
PCV valve every 24, 000 miles. On 1985-87 heavy duty cycle vehicles with dual air pump, except California, replace PCV valve every 54,000 miles.