Denso 5327 Spark Plug

Denso Iridium Power Spark Plug 5327

Denso Iridium Power spark plug 5327 is built for drivers who want precise ignition performance and stable combustion in a wide range of Ford, Jaguar, Cadillac, and GM applications. It uses a 0.4 mm iridium center electrode to promote efficient spark delivery, along with a tapered seat and 0.8 mm pre-gap for OE-style service fitment.

Key Features

• Iridium center electrode tip with a 0.4 mm fine-wire design
• Tapercut and U-groove ground electrode tip design
• 5000 ohm resistor for ignition noise control
• Copper core center electrode and nickel ground electrode core
• 14.00 mm thread diameter, 18.00 mm reach, 16.0 mm hex size
• Tapered seat type with 0.8 mm pre-gap
• Manufacturer heat range 22

Product Details

The Denso Iridium Power line focuses on compact electrode geometry for consistent spark exposure and efficient ignition performance. Part number 5327 uses an iridium tip at the center electrode, paired with a copper-core center and nickel-core ground electrode to support stable heat transfer and dependable operation in secondary ignition systems. This spark plug cross-references Denso Auto Parts IT22 for the same application.

Compatible With 2006-2009 Cadillac STS, 2006-2009 Cadillac XLR, 2005-2006 Ford GT, 2003-2004 Ford Mustang, 1996-1998 Ford Taurus, 1994-1996 Jaguar XJ12, 1994-1995 Jaguar XJS, and 1993 Jaguar XJRS. The Denso 5327 is also listed with OE cross-reference numbers used by Ford, General Motors, and Jaguar applications.

Common Issues This Part Can Address

• Misfire caused by worn or eroded spark plug electrodes
• Hard starting related to weak ignition spark
• Rough idle from inconsistent combustion
• Reduced throttle response from degraded ignition performance
• Ignition noise concerns where resistor-equipped plugs are specified

Installation Notes and Tips

Verify thread diameter, reach, seat type, and heat range against the vehicle’s original specification before installation. Check the pre-gap against the engine requirement and adjust only if the application calls for it. Use proper torque procedures for tapered-seat spark plugs to help prevent sealing issues and thread damage. Confirm the ignition system is in good condition before installing new plugs.

Quality Assurance

Denso manufactures the Iridium Power series with a fine-wire iridium center electrode and application-specific construction for secondary ignition service. Part number 5327 is built to match the listed fitments and OE-style specifications for the vehicles shown above.