Checks, in order
- Coolant level and capWith the engine cold, check the radiator and reservoir. A weak cap that does not hold pressure can cause boil-over and coolant loss.easy $ · under about $50
- Radiator and hosesLook for crusty residue, wet seams or a crack at the plastic end tanks. Squeeze the hoses (cold) for soft or swollen spots. Clear any debris packed between the radiator and A/C condenser.easy $ · under about $50
- Cooling fan or fan clutchWith the engine hot and idling, the fan should be pulling a lot of air. A fan that spins freely with the engine off, or is quiet and weak when hot, may have a failed clutch or drive.easy $ · under about $50
- ThermostatA thermostat stuck closed shows a quick temperature rise with a hot upper hose and a cold lower hose. A stuck-open one runs cool and heats poorly.medium $$ · about $50 to $500
- Water pump and head gasketLook for coolant at the pump weep hole and listen for bearing noise. Bubbles in the reservoir or white smoke point to a pressure test for a head gasket or leaking exhaust-side path.hard $$$ · shop-level job, $500+
Applies to: US-market UZJ100 Land Cruiser and Lexus LX 470, 1998 to 2007, with the 2UZ-FE 4.7L V8 (timing belt). AHC items apply to the LX 470 only; most US Land Cruisers have conventional shocks. Transmission is the A343F or A750F depending on year, so check the fluid spec for your truck.
Tools and parts for these checks
Links below are Amazon affiliate links: as an Amazon Associate, toyotadata earns from qualifying purchases, at no extra cost to you. Confirm fitment for your exact truck before you order.
| ITEM | USED FOR | BUY |
|---|---|---|
| Cooling system pressure tester | Finding coolant leaks and testing the radiator cap | Shop on Amazon |
| Toyota Super Long Life Coolant (50/50 premix) | Topping off or refilling with the factory-type coolant | Shop on Amazon |
| Infrared thermometer | Checking radiator, hose and thermostat temperatures | Shop on Amazon |
| Combustion leak (block) test kit | Checking coolant for exhaust gas from a head gasket | Shop on Amazon |
Go deeper
The same problem on other Toyotas
- 3rd Gen Tacoma (2016–2023): Engine temperature climbing or overheating warning
- 2nd Gen Tacoma (2005–2015): Engine overheating or temperature gauge climbing
- 1st Gen Tacoma (1995.5–2004): Engine overheating or temperature gauge climbing
- 5th Gen 4Runner (2010–2024): Temperature gauge climbing, coolant loss, or overheating
- 4th Gen 4Runner (2003–2009): Engine overheating or temperature gauge climbing
- 3rd Gen 4Runner (1996–2002): Engine overheating or temperature gauge climbing
- FJ Cruiser (2007–2014): Engine temperature gauge climbing, overheating or losing coolant
- 80 Series Land Cruiser (1991–1997): Temperature climbs when towing, climbing or on hot days
More 100 Series Land Cruiser / Lexus LX 470 problems
- Timing belt due, squeal or rattle from the front of the engine, or coolant and oil weeping at the front (Engine)
- Turn the key: click or nothing, engine won't crank (Starting & Charging)
- Engine cranks normally but won't start (Fuel & Ignition)
- Rough idle, stumbling or a misfire code (P0300 to P0308) (Fuel & Ignition)
- Check engine light with P0171, P0174 or air-fuel sensor codes (P2195, P2197) (Fuel & Ignition)
- Check engine light with secondary air injection codes (P2440, P2442, P2445, P0418), whirring at cold start (Emissions)
All 15 100 Series Land Cruiser / Lexus LX 470 symptoms in the interactive troubleshooter →
General guidance from owner experience. Confirm torque specs, fluid capacities and procedures in the factory service manual. Brakes, steering and anything structural: if in doubt, have a qualified shop inspect it before driving.