NGK 58939 Direct Ignition Coil Boot

NGK Coil on Plug Boot for Ford, Mazda, and Mercury

NGK Coil on Plug Boot 58939 is a premium direct ignition coil boot built for select Ford, Mazda, and Mercury applications. It is made for vehicles that use direct ignition coil boots instead of traditional spark plug wires, helping restore a reliable ignition connection at the plug.

Key Features

• Premium-grade direct ignition coil boot
• Black boot color
• Length: 3.94 in.
• NGK part number 58939
• NGK CPB-FD007 reference
• Built for coil-on-plug ignition systems

Product Details

NGK Coil on Plug Boot 58939 is part of the NGK Coil on Plug Boot line, a product family focused on ignition service parts for OE-style replacement needs. NGK draws on long-term ignition system experience and global OE expertise to produce replacement components that meet demanding durability and performance expectations. This boot is used in direct ignition setups where the coil connects directly to the spark plug, making it a practical service part for maintaining consistent ignition performance in Ford Focus, Ford Escape, Mazda 3, Mazda Tribute, Mercury Mariner, and Ford Transit Connect applications.

This part cross-references Beck/Arnley 175-1045 and Standard Ignition SPP88E for the same application.

What It Helps Address

• Misfire caused by a worn or damaged coil boot
• Weak spark transfer at the spark plug connection
• Ignition performance loss from heat-aged boot material
• Intermittent starting or rough running tied to coil boot wear
• Service replacement for direct ignition coil boot deterioration

Installation Notes and Fitment

Compatible With 2003-2011 Ford Focus, N/A; 2005-2008 Ford Escape, N/A; 2010-2013 Ford Transit Connect, N/A; 2004-2005 Mazda 3, N/A; 2005-2006 Mazda Tribute, N/A; 2008 Mazda Tribute, N/A; 2005-2008 Mercury Mariner, N/A. Vehicle notes indicate direct ignition coil boots are required and no wires are needed for these applications. Verify the ignition system configuration before installation and inspect the coil, plug well, and surrounding components for wear or contamination.

Quality Assurance

NGK is known for ignition-focused OE expertise and manufactures premium ignition products to support durability and operational performance standards used in modern vehicle service.