Thermostat

Thermostat replacement

Note: Drain Coolant before removal.

1. Disconnect Radiator Upper Hose.
2. Remove Thermostat Upper Housing.
3. Remove Gasket: discard & replace.
4. Remove Thermostat.

Note: Do not over-torque attachment bolts or the housing may crack.

Housing attachment torque: T = 12 N·m {1.2 kgf·m; 106 in-lb}.

(verified against scan p.151, 2026-08-30) — T=12 {1.2} is the only torque callout on the page, and its leader points to the housing attachment bolt at the top of the exploded diagram. The stray “32” was OCR pickup of adjacent diagram item numbers: “2” labels the Thermostat Upper Housing and “3” (with a small symbol box) labels the gasket. It is not a second torque value.

Thermostat opening test

1. Place Thermostat in a clear bowl and slowly raise the heat. Monitor the thermometer and verify opening temperature.

Limit: 82±1.5°C-88°C (180±3°F-190°F) — over this, replace.

(verified against scans p.151 and p.149, 2026-08-30) — both pages read as transcribed: printed p.151 states “Limit: 82±1.5°C88°C Over Replace” (plain 88°C), while printed p.149’s spec table gives “82±1.588±1.5°C”. The discrepancy is in the source manual itself, not an OCR artifact; the printed book carries both wordings.

Thermostat opening lift measurement

Limit: 95100°C (203212°F), full open, 8mm+ (0.31 in+).

Replace thermostats that fail to fully open at 100°C (212°F) (minimum full travel: 8mm (0.31 in)).

Applies to both SOHC and DOHC (our truck) — no separate spec given per valvetrain on this page.