DTC P0456 CAUSED BY EVAP LEAK AT VENT CONTROL VALVE O-RING This bulletin has been amended. See AMENDMENT HISTORY on the last page. Please discard previous versions of this bulletin.
full bulletin at NHTSA ↗2006 INFINITI QX56 engine problems
moderate 3 complaints filed with NHTSA · avg repair $3,100 · see engine across all vehicles →
When does it fail?
Of the 3 engine complaints filed for the 2006 INFINITI QX56, here's the actual mileage breakdown — failures cluster heaviest at 150,000+ mi.
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
Of the 5 model years of INFINITI QX56 we track for engine problems, this one has the fewest owner complaints on file (3).
No new NHTSA engine complaint has been filed on this vehicle in over 7 years — the issue may be aging out of the active population.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
INFINITI; DTC P0456 CAUSED BY EVAP LEAK AT VENT CONTROL VALVE O-RING This bulletin has been amended. See AMENDMENT HISTORY on the last page. Please discard previous versions of this bulletin.
full bulletin at NHTSA ↗QX56; REVISED UPPER OIL PAN AND TIMING CHAIN CASE PROCEDURES This bulletin is no longer active. Please discard previous versions of ITB10-055.
full bulletin at NHTSA ↗2005-2015 INFINITI VEHICLES; ECM REPROGRAMMING SERVICE INFORMATION This bulletin is no longer active. Please discard previous versions of ITB15-024.
full bulletin at NHTSA ↗VK56 CONNECTING ROD CAP BOLT SERVICE INFORMATION SERVICE INFORMATION A change has been made to the connecting rod cap bolt service part. The new service part (B in Figure 1) is visually different, but is a direct replacement for the original equipment part. IMPORTANT: See page 2 for the procedure to inspect the cap bolt service part for excessive stretch. If replacement of a single connecting rod cap bolt is indicated for any given connecting rod, both connecting rod cap bolts of the affected connecting rod must be replaced as a set.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
What owners are reporting 1 most recent
My 2006 Infiniti qx56 driver side manifold has cracked 4 times in 6 months. Each time it has cracked I was just driving normal road conditions. I have fixed it 4 times and am curious if this has anything to do with a prior recall on the arm suspension.
Common questions
How serious is the engine problem on the 2006 INFINITI QX56?
It's a documented issue but not catastrophic. 3 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Based on the 3 complaints filed, engine issues most often appear around 120,076 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.