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What the 9-4212S Kit Covers

Cold-start rattle on a 2002–2006 Altima 2.5L, or a recurring P0011? The timing drive is the usual culprit. The Timing Chain Kit For Nissan Altima 2002-2006 2.5L DOHC 16v QR25DE (9-4212S) replaces that drive in one order: chain, tensioner, both guide rails, crank sprocket, and the front cover gasket set.

The engine is the QR25DE, a 2.5L DOHC inline-4 used across Nissan's L31 Altima platform. Koeep cross-references the kit against OEM part numbers 13028-8J00A (chain), 13070-8J00A (tensioner), and 13085-8J00A (guide set), and builds it to 2026 aftermarket compliance thresholds under ISO 9001:2025 quality protocols and SAE J2000-series elastomer aging standards.

The numbers that matter:

• Chain: single-row silent type, 8 mm pitch, 148 links
• DTC resolution: P0011, P0014, P0340, plus secondary misfire codes P0300–P0304
• Service life: 100,000 miles under SAE J2809 severe-service cycles, on 5W-30 full-synthetic oil
• Diagnostics: readable in OBD-II/CAN 2.0B environments and on 2026 CAN-bus 3.0 scan tools

Fitment: Three QR25DE Platforms

The QR25DE did not stay in the Altima. The kit's cross-reference list covers three platforms:

• Nissan Altima (L31), 2002–2006
• Nissan Sentra SE-R (B15), 2002–2006
• Nissan Quest (V42), 2004–2009

Servicing an X-Trail or Sentra 2.5L from the same era? Koeep lists a separate timing chain kit compatible with Nissan 2002-2006 Sentra, Altima, and X-Trail L4 engines for those applications. For the wider rebuild — heads, gaskets, oil pumps, rotating assemblies — the Engines & Engine Parts collection holds the full catalog.

Inside the QR25DE Timing Drive

The stock setup is a single-row silent-type chain, 8 mm pitch, 148 links. When it stretches, you hear the classic cold-start rattle at 1,800–2,200 RPM — the sound of slack, as the tensioner plunger runs out of travel before oil pressure stabilizes.

The 9-4212S upgrades each wear point instead of just matching the original parts:

• Chain links: induction-hardened SAE 4140-series alloy steel, chromium-carbonitrided pin bushings at HV 1,100–1,200, tensile strength of 28.5 kN or more per SAE J1998 — the surface treatment Nissan adopted on 2020+ genuine-service QR-family parts.
• Guide rails: high-modulus PA46 with an embedded 0.8 mm PTFE wear strip, cutting chain-slap harmonics by 30% versus OE nylon 6/6 guides.
• Hydraulic tensioner: glass-fiber-reinforced PA66 body rated for 150°C continuous exposure (ASTM D6779), ratcheting pawl with a 12-tooth detent and 38 mm plunger travel. It holds static tension for more than 72 hours after shutdown, where early L31 units bled down on cold-soak starts.
• Crank sprocket: 21-tooth sintered-ferrous alloy, isotropic finish, tooth profile hardened to HRC 56–58.

Full Component Specifications

Values for the 9-4212S kit, validated against 2026 SAE/IATF 16949 quality benchmarks with full material traceability.

Before You Disassemble: The Pre-10/2004 Spacer

DTC Mapping: Codes This Kit Clears

Use this map to decide whether the chain drive is your root cause:

• P0010–P0025 — camshaft actuator and timing: primary resolution for P0011 and P0014.
• P0340–P0349 — camshaft position sensor circuit: resolves P0340 correlation faults caused by chain stretch.
• P0300–P0304 — misfire cascade: secondary resolution; the misfire follows valve-timing drift, not coils or injectors.
• P0420 — catalyst efficiency: tertiary resolution. Delayed exhaust-valve timing enriches post-catalyst O₂ readings and drags efficiency down.

How a Stretched Chain Fakes a Misfire

Elongation past 1.5% creates a 4°–6° valve-timing phase error. On the QR25DE that retards intake-valve closing enough to cut cranking compression by 8–12 psi per cylinder — yet not far enough to trip the P0011 threshold, which typically sits above 8°. The ECU logs P0300 and sends you chasing ignition parts.

There is a faster test: scope the crank sensor at 500 mV/div against a known-good QR25DE reference pattern. A 2–3 ms phase shift at 3,000 RPM confirms chain elongation before you replace coils or injectors.

Why Cold Starts Flag P0011 Sooner Now

Below 5°C ambient, a chain stretched by 0.8–1.2% of pitch length lets the plunger reach its full 38 mm extension before oil pressure builds. 2026 IM240 emission-test calibrations sample the rationality check at 100 Hz — double the 50 Hz of pre-2020 ECUs — so the fault flags tighter. A fresh kit restores cam-crank correlation within ±3°.

Service Life After Installation

Nissan has never specified a replacement interval for the QR25DE chain — it is designated a "lifetime" component. Fleet data disagrees: databases aligned with SAE J2809 severe-service duty cycles recommend inspection at 120,000 miles and proactive replacement by 150,000 miles.

The 9-4212S is validated for 100,000 miles post-installation with 5W-30 full-synthetic oil — an 8–10 year fleet horizon projected through 2030–2034.

Ordering, Quotes, and Support

The main product page carries the full 9-4212S listing. Koeep also keeps the identical kit on a second product page under the same title, so the same 9-4212S spec is reachable from two points of access.

Request a Quote

Direct channels:

• RFQ form: https://koeep.com/pages/request-for-quote
• Email: support@koeep.com
• WhatsApp: +86 181 3883 8291

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