P0021 on Infiniti: How to Diagnose & Fix
Intake Camshaft Position Timing - Over-Advanced (Bank 2)
5 Infiniti models · 5 documented issues · 5 critical · $900-$5,000 repair
P0021 on Infiniti by model: symptoms, diagnosis and fix
The VQ37VHR runs three timing chains — a primary and two secondaries — with plastic guides and hydraulic tensioners. The chains stretch and the guides wear, and because the tensioners rely on oil pressure to take up slack, any oil pressure loss or extended change interval accelerates it sharply. The first symptom is a rattle from the front of the engine on cold start that lasts a second or two until pressure builds, progressing to a rattle that persists at idle. Left alone, stretch pushes cam timing out of correlation and sets timing codes; in the worst outcome the chain skips or a guide fragments, and on this interference engine that means bent valves.
Common Symptoms
- Rattle from the front of the engine on cold start
- Rattle that persists at idle once warm
- Check engine light with cam or crank correlation codes
- Rough running or reduced power
- Whining or chain slap that changes with RPM
How to Fix
Treat a front-of-engine rattle on cold start as a timing chain issue and act on it rather than waiting for a code — chain, guides, and tensioners replaced proactively is a fraction of the cost of a destroyed engine, though it is still a substantial job because the front cover comes off. Have the shop scan for cam and crank correlation codes and check actual cam timing against spec. Critically, verify oil pressure at the same time: on this engine the chain rarely wears out on its own, it wears out because oil pressure dropped from a leaking cam cover or oil gallery gasket, and replacing the chain without fixing the pressure loss just repeats the failure. Change oil every 5,000 miles with full synthetic instead of following the extended factory interval. On a used purchase, insist on a genuine cold start before buying.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- OEM VQ37VHR timing kitOEMZ1-configured Nissan OEM VQ37VHR timing kit
Confirmed VQ37VHR chain/guide/tensioner repair Fitment/availability: Configure the exact G37 model year and choose the required chains, guides and cam-chain tensioners. Do not buy from noise alone; compare included components with the VI…
- OEM VQ35HR/VQ37VHR timing-cover O-ring and seal kitOEMNissan OEM VQ35HR/VQ37VHR timing-cover O-ring and seal kit
Conditional disturbed-seal bundle for the front-cover timing procedure Fitment/availability: Match kit contents to the exact VQ37VHR service procedure and VIN. It supports front-cover reassembly but does not diagnose or repair chain wear…
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Sources for this issue (2)
The VQ37VHR and VQ35HR engines in the M/Q70 series develop timing chain tensioner wear, leading to chain rattle on startup and potential chain skip. The hydraulic tensioners lose their ability to maintain proper chain tension as the internal check valve wears.
Common Symptoms
- Chain rattle on cold start lasting 1-3 seconds
- Check engine light with cam timing codes
- Rough idle after extended parking
How to Fix
Replace the primary timing chain tensioners and inspect the chains and guides. Use updated tensioner part numbers that feature improved check valve design. This repair requires removing the front timing cover.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Infiniti VQ37 lower primary timing-chain tensionerOEM13070-1MR0A
Confirmed lower primary hydraulic-tensioner failure branch Fitment/availability: 13070-1MR0A is the lower/primary tensioner cataloged for the 3.7L VQ family and shown in the Q70 engine catalog. Confirm 2014-2019 Q70 3.7L VIN and exact fa…
- Genuine Infiniti VQ37 primary timing chainOEM13028-JK20A
Measured primary-chain wear or damage branch during confirmed timing repair Fitment/availability: 13028-JK20A is the primary camshaft timing chain shown for Q70 VQ37VHR; the catalog also has two 13028-JK20B secondary chains. Confirm VIN …
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Sources for this issue (1)
The VK45DE V8 used in the FX45 can develop timing chain guide and tensioner wear, leading to chain rattle on startup or at idle. Owners report the issue more often on higher-mileage engines or vehicles with poor oil change history, where sludge and low oil pressure accelerate guide and tensioner wear.
Common Symptoms
- Rattling noise on cold start
- Metallic chain noise at idle
- Check engine light
- Rough running or timing-related misfire
- Noise from front of engine
How to Fix
Diagnosis usually starts with confirming front cover chain noise during cold start and checking oil condition, oil pressure, and cam/crank correlation data. Repair typically involves replacing timing chain guides, tensioners, and often the primary chain while the front timing cover is removed; parts and labor are substantial because of the engine teardown. Typical repair cost runs about $1,800 to $3,500 depending on how many timing components are replaced.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Infiniti VK45DE camshaft timing chainOEMInfiniti 13028-6N200
chain replacement after measurable wear, damage or timing-set service is confirmed Fitment/availability: Infiniti 13028-6N200 replaces 6N210 and fits the 2003-2008 FX45 VK45DE.
- Genuine Infiniti VK45DE right-side timing-chain tensionerOEMInfiniti 13070-AR000
right-bank chain-tensioner branch during confirmed timing-system repair Fitment/availability: Infiniti 13070-AR000 is the VK45DE right-side chain tensioner cataloged for 2003-2008 FX45. It is paired with, not substituted for, the left-si…
- Genuine Infiniti VK45DE left-side timing-chain tensionerOEMInfiniti 13070-AR015
left-bank chain-tensioner branch during confirmed timing-system repair Fitment/availability: Infiniti 13070-AR015 replaces AR010 and is cataloged for 2003-2008 FX45 VK45DE.
- Genuine Infiniti VK45DE right-side slack chain guideOEMInfiniti 13091-AR000
right-side slack-guide branch during confirmed complete timing-system service Fitment/availability: Infiniti 13091-AR000 is a right-side/slack-side VK45DE guide cataloged for 2003-2008 FX45. It is only one of four side-specific guides; A…
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Owner tips & cautions
- TipUse high-quality synthetic oil and avoid extended oil change intervals, since dirty oil is commonly blamed for accelerating chain guide and tensioner wear.
- TipIf startup rattle lasts more than a second or becomes frequent, inspect it early before chain slack causes cam timing faults.
Sources for this issue (1)
Owners of VK56VD-equipped M56 models report startup rattle and persistent front-engine timing noise related to timing chain guide and tensioner wear. As mileage increases, slack in the primary chain system can affect valve timing and trigger correlation faults, especially when oil change intervals have been extended.
Common Symptoms
- Rattle from front of engine on cold start
- Check engine light
- Rough idle or reduced power
- Engine timing-related noise at idle
- Intermittent cam/crank correlation faults
How to Fix
Diagnosis starts with confirming cold-start rattle, checking oil condition/pressure, and scanning for cam/crank correlation codes. Repair typically involves replacing the timing chains, guides, and tensioners, and resealing the front cover; on this engine the labor is substantial, so total repair commonly runs from about $2,500 to $5,000 depending on parts replaced and shop rate.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- OEM 2011-2019 M56/Q70 5.6L timing-chain service kitOEMZ1 assembled OEM VK56VD timing kit
Confirmed VK56VD chain/guide wear branch after campaign-history and mechanical diagnosis Fitment/availability: Fits 2011-2019 M56/Q70 VK56VD and includes the primary left/right chains, guides and tensioners, with selectable additional co…
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- TipUse high-quality synthetic oil and avoid extended oil intervals; owners report chain noise is more common on engines with inconsistent maintenance.
- TipIf startup rattle lasts more than a brief second, inspect immediately to avoid chain jump and more severe engine damage.
Sources for this issue (1)
Owners of the 3.7L VQ37VHR-equipped QX50 report a metallic rattle at cold start and oil seepage from the front timing cover area. On this engine, timing chain guide/tensioner wear and RTV-sealed front cover leaks can develop with age and heat cycling; because the VVEL/timing components sit behind the front cover, diagnosis often starts with distinguishing harmless brief startup noise from persistent chain or guide wear. Multiple owner complaints and repair discussions note oil smell, visible seepage down the front of the engine, and expensive labor because the front cover must be resealed and timing components inspected at the same time.
Common Symptoms
- metallic rattle for 1-3 seconds on cold start
- oil smell after parking
- oil seepage on front of engine
- small oil spots under front of vehicle
- low oil level between services
How to Fix
Inspect for oil seepage around the front timing cover, upper oil pan junction, and valve cover areas to confirm the leak source before authorizing repairs. If startup rattle is persistent or worsens, check chain tensioner operation and timing correlation, then reseal the front cover with OEM-equivalent RTV and replace worn guides/tensioners as needed. Because labor overlap is substantial, many owners replace the water pump, drive belt, and related seals during the same job.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Infiniti VQ37 lower primary timing-chain tensionerOEM13070-1MR0A
Confirmed lower primary hydraulic-tensioner failure branch Fitment/availability: 13070-1MR0A is the lower/primary tensioner cataloged for the VQ37 timing system. Confirm 2014-2017 QX50 3.7L VIN and failed position; it is not either bank'…
- Genuine Infiniti VQ37 primary timing chainOEM13028-JK20A
Confirm QX50 VIN and measured primary-chain wear; it is one chain rather than a complete timing kit and does not justify automatic replacement of secondary chains, sprocket
- Genuine Infiniti VQ37 water-pump kitOEMB1010-JK20A
Confirmed leaking/noisy water-pump or approved labor-overlap branch Fitment/availability: B1010-JK20A is the genuine water-pump kit cataloged for 2014-2017 QX50 3.7L VQ37VHR.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Owner tips & cautions
- TipHave the leak source dye-tested first; valve cover seepage can mimic a front cover leak, and misdiagnosis can turn a moderate repair into a very expensive one.
- TipIf the front cover is being removed, ask the shop to inspect timing chain guides, tensioners, and water pump at the same time to avoid duplicate labor later.
Sources for this issue (1)
P0021 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0021 mean on a Infiniti?
P0021 stands for "Intake Camshaft Position Timing - Over-Advanced (Bank 2)." P0021 means the engine computer detected that the intake camshaft on bank 2 is timed too far advanced and won't return to its commanded position. Most modern engines use variable valve timing (VVT), where an oil-pressure-driven actuator rotates the camshaft to optimize power and efficiency; the PCM compares the camshaft's actual position to its target. When the cam stays over-advanced beyond an acceptable limit, this code sets. Bank 2 refers to the side of the engine that does not contain cylinder number one. You may notice rough idle, reduced performance, or lower fuel economy. On Infiniti it is documented across 5 models: G37, Q70, FX45, M56, QX50.
What are the most common causes of P0021?
The most common causes of P0021 are: Dirty or low engine oil restricting the VVT system, Stuck or failed camshaft oil control valve (VVT solenoid) on bank 2, Clogged VVT solenoid screen or oil passage, Faulty camshaft position actuator / phaser, Wiring or connector fault at the VVT solenoid, Camshaft or crankshaft position sensor problems, Worn timing chain, guides, or stretched chain altering cam timing. The specific cause varies by vehicle.
How much does it cost to fix P0021 on a Infiniti?
Published repair estimates on Infiniti range from $900 to $5,000 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
Looking for P0021 on a different make?
View P0021 across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.