P0018 on Buick: How to Diagnose & Fix
Crankshaft/Camshaft Position Correlation - Bank 2 Sensor A
2 Buick models · 2 documented issues · 2 critical · $2,000-$4,500 repair
P0018 on Buick by model: symptoms, diagnosis and fix
The GM 3.6L LLT (built 2007-2011) and LFX (built 2012 on) "High Feature" V6 in LaCrosse, Enclave, Acadia, Traverse, CTS, Cadillac SRX, and many others suffers timing chain stretch typically between 80,000-150,000 miles. Root cause is oil-related — original OLM intervals (up to 12,000 miles) starved the chain of fresh oil. Excessive oil consumption (LLT also has a known consumption issue) accelerates wear.
Common Symptoms
- cold start rattle
- check engine light
- extended cranking
- misfire
- low oil between changes
How to Fix
Full timing chain kit ($2,000-$4,500 incl. labor) — both primary and secondary chains, all tensioners and guides. Switch to 5,000-7,500 mile oil intervals with full-synthetic dexos1 5W-30. LLT engines may also need PCV valve replacement to reduce oil consumption (TSB 10-06-01-007).
Sources for this issue (2)
The 3.6L high-feature V6 in 2008-2013 Enclaves is prone to timing chain stretch and worn chain guides/tensioners, sometimes appearing as early as 40,000-60,000 miles. As the chain elongates, valve timing drifts, triggering misfires and a rattle at idle/startup; if a chain jumps a tooth it can bend valves and cause catastrophic engine damage. GM acknowledged premature chain wear under certain driving conditions with the vehicle's original oil change intervals and issued Special Coverage Adjustment #11340C extending the chain warranty to 10 years/120,000 miles, but for the Enclave it covers only the 2009 model year.
Common Symptoms
- Rattling noise at idle or cold startup
- Check engine light
- Engine misfire / rough running
- Reduced engine power message
- Metal shavings in oil
How to Fix
Replace the timing chains, guides, and tensioners (a full front-of-engine job). On a 2009 Enclave, GM Special Coverage #11340C made the chain replacement free up to 10yr/120k mi (or, if the chain did not need replacing, an ECM reprogram); otherwise it is an out-of-pocket repair. Keeping oil changes current and using correct-spec oil slows wear.
Sources for this issue (1)
P0018 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 P0018 mean on a Buick?
P0018 stands for "Crankshaft/Camshaft Position Correlation - Bank 2 Sensor A." This code means the computer detected that the crankshaft and the Bank 2 'A' (typically intake) camshaft are out of their expected timing relationship. The computer compares the crankshaft and camshaft position sensor signals; they should stay in a fixed correlation as the engine turns. When the Bank 2 camshaft is too far off from the crankshaft, P0018 sets, indicating the valve timing on that bank is misaligned. This can cause rough running, reduced power, hard starting, or a no-start, and in some cases signals timing chain or phaser trouble that warrants prompt attention. On Buick it is documented across 2 models: LaCrosse, Enclave.
What are the most common causes of P0018?
The most common causes of P0018 are: Stretched, worn, or jumped timing chain (Bank 2), Worn or broken timing chain guides/tensioner, Stuck variable valve timing solenoid or phaser, Low or dirty engine oil affecting the phaser, Faulty crankshaft or camshaft position sensor, Damaged reluctor/tone ring, Incorrect timing from prior service, Wiring or connector fault at a cam/crank sensor. The specific cause varies by vehicle.
How much does it cost to fix P0018 on a Buick?
Published repair estimates on Buick range from $2,000 to $4,500 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.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.