Symptoms
Coolant disappearing with no visible leak, pressurised hoses after hard work, or temperature that climbs when a thermostat is fitted.
The fix, step by step
- Members' advice on an SD33T that kept boiling after a pressure-tested, rebuilt head: start with the radiator.
- Have it properly cleaned or replaced, then fit a new cap, top and bottom hoses and the correct thermostat, and check the fan clutch hub.
- Never run it without a thermostat.
- If temperature rises with one fitted, there's a flow restriction.
- Use real coolant: owners report water pumps wearing out on engines run on plain water.
- If the head must come off, buy an SD33T-specific head gasket, as the non-turbo gasket doesn't fit the turbo engine correctly.
Tools & part numbers
- Cooling-system pressure tester
- infrared thermometer
- torque wrench (head)
- workshop manual
Where to buy the parts
Nissan Patrol MQ radiator, hoses and thermostat (search)Supercheap Auto ↗
Hunting a used or discontinued part? Search eBay Motors for Nissan Patrol 160 / MQ parts →
Rated for a competent home mechanic with a decent tool kit. Confirm torque figures, fluids and procedures against the factory service manual for your VIN, support the truck on stands rather than a jack, and work at your own risk (disclaimer). Some parts links are affiliate links, which pay us a small commission at no cost to you.