Yanmar 4TNE88 — Waste gate valve adjusting method
Adjustments · Turbocharger waste gate
For the Yanmar 4TNE88, from the Yanmar service manual.
Applies to: Yanmar 4TNE88, Yanmar TNE series engine
Before you start
- Do not apply over 5 kg/cm2 to the actuator.
- If adjustment is impossible, replace the whole turbocharger ass'y.
Procedure
- Set the manometer control pressure (Pc) applied to the waste gate actuator to 0 and set the dial gage to zero.
- Gradually open the pressure regulating valve and measure the Pc value when the actuator rod is operated by 2 mm.
- For hysteresis, let the rod move to 3 mm then gradually close the valve and measure pressure at 2 mm.
- Apply 1.2 kg/cm2 to the actuator and hold for 1 minute; the actuator is good if pressure is 1.1 kg/cm2 or more.
Tools required
- Dial gage Amazon
- Manometer Amazon
- Pressure regulating valve Amazon
- Pressure reducing valve Amazon
- Pressure gage Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Pc (control pressure) 600 to 750 mmHg
- Actuator leak test 1.2 kg/cm2 held 1 minute
Full service-parts list: Yanmar 4TNE88 →
Source: Yanmar service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.