Symptoms
A ticking noise from the engine bay that is loudest cold and often fades as the manifold heats and expands. The cause is a paper-thin crack where the flange meets the first pipe.
The fix, step by step
- Soak every fastener in penetrating oil for days beforehand.
- The engine mounts must be released, and the engine raised, to reach the lower manifold studs.
- Replace the manifold assembly with new gaskets, studs and nuts.
- Expect seized or broken studs on rusty trucks.
- Afterward, idle the engine for about half an hour to burn off manufacturing oil.
Tools & part numbers
- Engine support or jack
- penetrating oil
- stud extractor set
- new manifold, gaskets, studs and nuts
Where to buy the parts
Exhaust manifold gaskets, 2005 GX 470RockAuto ↗Amazon ↗
Exhaust flange studs and nuts, 2005 GX 470RockAuto ↗Amazon ↗
Exhaust manifold gasket, 2UZ-FE to 04/2005 (confirm for VVT-i trucks)CruiserTeq ↗Amazon ↗
Hunting a used or discontinued part? Search eBay Motors for Lexus GX 470 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.