Parts for your 2004 Toyota Bb-Timing belt kit

2004 Toyota bB timing-belt-kit — what’s actually fitted

For the 2004 Toyota bB (NCP30/NCP31), a timing-belt-kit isn’t relevant because the vehicle doesn’t use a timing belt at all — it runs a timing chain. This applies to the common bB engines of the era, the 1NZ‑FE (1.5L) and 2NZ‑FE (1.3L). Both are chain-driven, so there’s no belt, no belt tensioner, and no belt pulleys to replace as a kit.

Technical sources that confirm the chain-driven setup include:

• Toyota service literature for the 1NZ‑FE/2NZ‑FE engines (chain-driven camshafts with hydraulic tensioner and chain guides)
• Toyota Electronic Parts Catalogue (EPC) for NCP30/NCP31 bB, which lists a timing chain, guides and tensioner, not a belt
• Owner’s and service information for the Scion xB (the export twin of the bB) noting a timing chain with no scheduled belt replacement
• Major aftermarket catalogues (e.g., Gates, Aisin) showing no timing-belt listing for 1NZ‑FE/2NZ‑FE

Why a chain and not a belt? Toyota designed these NZ-series engines with an oil-fed timing chain system for durability and reduced routine maintenance. The chain runs inside the engine under the timing cover, is lubricated by engine oil, and is kept tight by an automatic hydraulic tensioner and guides. Because there’s no rubber belt, there’s no periodic belt-change interval like you’d see on belt-driven engines.

What should owners and workshops focus on instead? Good oil hygiene is the big one. Regular oil changes with the correct grade help keep the chain, tensioner and VVT gear happy. If the vehicle’s done big kilometres, it’s smart to listen for cold-start rattles, check for oil leaks around the timing cover, and inspect the accessory (serpentine) belt and water pump — the water pump on these engines is driven by the accessory belt, not by a timing belt.

Typical service advice for a 2004 bB with a timing chain:

• Change engine oil and filter on time to prevent chain and tensioner wear
• Investigate rattles at start-up or mis-timing codes (possible stretched chain, worn guides, or tired VVT cam gear)
• Replace the accessory belt and idler if cracked/noisy, replace the water pump if leaking or rough
• If the timing cover is removed, budget for new seals/gaskets and fresh coolant and oil

Bottom line: there’s no timing-belt-kit for a 2004 Toyota bB because it doesn’t need one. If you’re shopping for parts, look for timing chain components only if there are symptoms, or stick to routine servicing that keeps the chain system in good nick.

Popular questions

Does the 2004 Toyota bB have a timing belt or a chain?
It has a timing chain. The 1NZ‑FE and 2NZ‑FE engines fitted to the 2004 bB are chain-driven, so there’s no timing belt to replace. This is supported by Toyota service information and parts listings for the NCP30/NCP31 bB and the equivalent Scion xB.

When should the timing chain be replaced on a 2004 bB?
There’s no fixed replacement interval. A healthy chain can last the life of the engine with regular oil changes. Replacement is considered only if there are symptoms like cold-start rattles, cam/crank correlation faults, or obvious chain wear found during diagnosis.

Is there a timing-belt-kit available for the 2004 bB?
No. Because the engine uses a chain, you won’t find a genuine “timing-belt-kit” for this model. If repairs are required, technicians source timing chain components (chain, guides, tensioner, possibly VVT gear) or service the accessory belt system and water pump separately.