Lexus GX 470: Timing belt due or history unknown, coolant weep at the front of the engine

Checks, in order

1. Find the history
   Look for a sticker on the timing cover or radiator support, dealer records, or receipts. No proof means it is due.
   easy $ · under about $50
2. Look for the pump
   Coolant crust or a drip at the bottom of the timing cover is the water pump weeping behind the belt. That moves the job from scheduled to soon.
   easy $ · under about $50
3. The job
   Belt, water pump, tensioner, idlers, thermostat, and the cam and crank seals if they are damp. Independent shops run about $1,200–1,700; dealer quotes owners have posted range from $1,400 to $2,700, with seals and the serpentine belt adding to it.
   hard $$$ · shop-level job, $500+

Applies to: Lexus GX 470, 2003 to 2009, with the 4.7L 2UZ-FE V8 (timing belt) and the A750F 5-speed automatic. Every US GX 470 has rear air suspension; KDSS was optional from 2004. It shares its chassis with the 4th gen 4Runner and 120 Series Prado, so many 4Runner parts and procedures apply.

Tools and parts for these checks

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Go deeper

• Toyota 2UZ-FE 4.7 V8: Specs, Reliability & High Mileage Guide

The same problem on other Toyotas

• 100 Series Land Cruiser / Lexus LX 470 (1998–2007): Timing belt due, squeal or rattle from the front of the engine, or coolant and oil weeping at the front

Other engine problems on the Lexus GX 470

• Ticking from the engine on cold start that fades as it warms

More Lexus GX 470 problems

• Rear end sags overnight or leans, compressor runs long or never, suspension warning light (Steering & Suspension)
• Rust on the frame, or play and a torn boot at the lower ball joints (Frame & Body)
• VSC TRAC and VSC OFF lights on, with or without a check engine light (Body & Electrical)
• Dashboard cracked, sticky or shiny and soft in the heat (Body & Electrical)
• Rear swing-out door will not open from outside or inside, or will not latch (Body & Electrical)
• Check engine light with P0171 and P0174 (both banks lean) (Fuel & Ignition)

All 11 Lexus GX 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.