P0021: How to Diagnose & Fix — Intake Camshaft Position Timing - Over-Advanced (Bank 2)
45 vehicles · 14 makes · $40-$32,000 repair
How to diagnose and fix P0021: most-reported vehicles
Ranked by owner reports. Each card gives the symptoms, how to confirm the cause, the fix, parts and sources for that vehicle.
Ford Mustang · 2015–2023
Two distinct tick patterns affect 5.0L Coyote V8 in 2015-2023 Mustang depending on engine generation. Gen 2 Coyote (2015-2017): light tick at idle and on cold start, commonly attributed to valve lash / lifter operation; generally cosmetic and not associated with engine damage. Gen 3 Coyote (2018-2023): louder, more pronounced tick — same family but Ford changed to plasma transferred wire arc (PTWA) cylinder liners. The tick is increasingly linked to piston slap from clearance issues against the plasma liner, with some confirmed cases of cylinder wall scoring requiring engine replacement under warranty. Direct injection (added on Gen 3 alongside port injection) contributes a separate fainter HPFP tick that is normal. Distinguishing: Gen 2 tick stays constant warm; Gen 3 piston slap diminishes as engine warms but returns under load. Owner forums (Mustang6G, MPR Racing Engines) document the Gen 3 pattern extensively.
Common Symptoms
- Tick or tap noise at idle
- Typewriter-like clicking sound
- Metallic rattle on cold start
- Noise that diminishes when warm
- Ticking more pronounced after oil change
How to Fix
Ford TSB 14-0156 addresses this as a normal characteristic, stating no repair should be attempted. Using Ford's recommended oil (Motorcraft 5W-20 or 5W-30) and changing oil at 5,000-mile intervals may help. For persistent issues, VCT solenoid replacement ($200-400) or cam phaser service ($1,500-3,000) may help.
Sources for this issue (1)
Jeep Cherokee · 2014–2023
Multiple factors cause sudden engine stalling including low oil levels (2.4L), VVT issues, faulty sensors, fuel system problems, and transmission-related stalling (2019 9-speed). Stalling typically emerges after ~1,000 miles.
Common Symptoms
- Engine stalls during turns
- Sudden stalling at idle or low speed
- Misfires leading to stalling
- Engine cuts out without warning
- Difficult restart after stalling
How to Fix
Diagnosis required to identify root cause: check oil level (especially 2.4L), test MAF and throttle position sensors, inspect VVT system, check fuel pump pressure, verify transmission software updates applied.
Owner tips & cautions
- WarningFor 2.4L engines: Check oil level weekly - stalling often due to low oil
- TipDocument stalling incidents with date, mileage, conditions for warranty
Sources for this issue (1)
Nissan Frontier · 2005–2019
The Nissan Frontier VQ40DE 4.0L V6 is notorious for timing chain guide and tensioner failure, typically occurring between 80,000-130,000 miles. The plastic chain guides deteriorate and break apart, causing chain rattle and potential engine damage. This is one of the most well-known issues with the Frontier. Nissan issued a Service Campaign for some model years.
Common Symptoms
- Loud rattling on startup that fades
- Persistent chain rattle at idle
- Check engine light with P0300/P0011/P0021 codes
- Metal debris in oil
- Engine timing jumping
How to Fix
Replace all timing chain guides, tensioners, and chains. The job requires significant labor as the engine must be partially disassembled. Use updated Nissan timing chain kit. Total cost: $1,500-3,000. Some independent shops specialize in this repair for $1,200-2,000.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Nissan updated secondary timing chain 13028-ZK01C
Quantity two; confirm VIN and bulletin applicability.
- Genuine Nissan secondary tensioner shoe 13097-ZK01C
Use only for a confirmed applicable VQ40DE secondary-chain repair; quantity two.
As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.
Toyota Sienna · 2007–2020
Mazda Mazda6 · 2009–2021
Find P0021 by make
Browse every documented model and issue for your make.
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?
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.
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?
Repair costs for P0021 range from $40 to $32,000, depending on the vehicle and root cause.
Which vehicles are affected by P0021?
Au7o has documented P0021 across 45 vehicle models from 14 manufacturers: BMW, Chevrolet, Dodge, Ford, GMC, Infiniti, Jeep, Lexus, Mazda, Mercedes-Benz, Nissan, Subaru, Toyota, Volkswagen.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.