When should Pacifica spark plugs be replaced?

The manual's Maintenance Plan for 3.6L Gas and Hybrid Models lists these items in its Additional Maintenance section:

Because the spark plug interval is mileage-based only, a Pacifica that is driven few miles a year does not reach its spark plug change by age; the change comes due at 100,000 miles.

From the 2026 Chrysler Pacifica owner's manual (Maintenance Plan, 3.6L Gas and Hybrid Models), read November 9, 2026.

Other items due at 100,000 miles

In the same maintenance plan, the 100,000-mile (160,000 km) column also lists Replace PCV valve and Flush and replace the engine, power electronics, and battery coolant at 10 years or 150,000 miles (240,000 km), whichever comes first. A footnote to the coolant item says some vehicles require special tools to add coolant properly, that failure to fill these systems properly could lead to severe internal damage, and that if any coolant needs to be added you should contact your local authorized dealer.

The plan also lists replacing the front accessory drive belt, and inspecting the front accessory drive tensioner and idler pulley, at 150,000 miles (240,000 km) or 15 years.

From the 2026 Chrysler Pacifica owner's manual (Maintenance Plan, 3.6L Gas and Hybrid Models), read November 9, 2026.

Fuel that shortens spark plug life

The manual's fuel section says MMT (methylcyclopentadienyl manganese tricarbonyl) is a manganese-containing metallic additive blended into some gasolines to increase octane. It says gasoline blended with MMT provides no performance advantage beyond gasoline of the same octane number without MMT, and that it reduces spark plug life and reduces emissions system performance in some vehicles.

The manufacturer recommends that gasoline without MMT be used in your vehicle. The MMT content of gasoline may not be indicated on the gasoline pump, so the manual says you should ask your gasoline retailer whether the gasoline contains MMT. MMT is prohibited in Federal and California reformulated gasoline.

From the 2026 Chrysler Pacifica owner's manual (Methylcyclopentadienyl Manganese Tricarbonyl (MMT) In Gasoline), read November 9, 2026.

Misfire and the check engine light

The manual says that when the engine is running, the Malfunction Indicator Light (MIL) may flash to alert serious conditions that could lead to immediate loss of power or severe catalytic converter damage, and that the vehicle should be serviced by an authorized dealer as soon as possible if this occurs.

Its catalytic converter section adds that, in the event of engine malfunction, particularly involving engine misfire or other apparent loss of performance, you should have your vehicle serviced promptly. Continued operation with a severe malfunction could cause the converter to overheat, resulting in possible damage to the converter and vehicle.

From the 2026 Chrysler Pacifica owner's manual (Malfunction Indicator Light; Catalytic Converter), read November 9, 2026. The manual warns that failure to properly inspect and maintain your vehicle could result in a component malfunction and affect vehicle handling and performance.

Chrysler Pacifica service at Elgin CDJR

If your Pacifica is nearing 100,000 miles or the check engine light is flashing, our Chrysler service center can handle the spark plugs and the other scheduled maintenance in your owner's manual. Our service department is open Monday to Friday 7 a.m. to 7 p.m. and Saturday 7:30 a.m. to 4 p.m., and is closed Sunday. Elgin CDJR is at 1500 W. Lake St. in Streamwood. Get directions.