Bosch 79104 Spark Plug

Bosch Nickel Spark Plug for Volkswagen Applications

Bosch 79104 is a conventional nickel-copper spark plug built for steady ignition performance and value. It uses a heavy-duty yttrium-enhanced nickel center electrode with a copper core, along with a nickel ground electrode, to support durable service in everyday driving.

Compatible With 2008-2015 Volkswagen Jetta, 2009-2010 Volkswagen Beetle, 2012-2014 Volkswagen Beetle, 2010-2014 Volkswagen Golf, and 2012-2014 Volkswagen Passat. Bosch 79104 is a direct-fit ignition service part for drivers maintaining factory-style secondary ignition performance.

Key Features

• Conventional nickel-copper spark plug design
• Yttrium-enhanced nickel center electrode with copper core
• Nickel ground electrode tip with standard J-gap configuration
• Resistor spark plug with 6000 resistance rating
• Projected ceramic insulator for stable ignition characteristics
• 14 mm thread diameter, 19 mm reach, flat seat
• Heat range 7 with 1.1 pre-gap size
• Non-removable nut terminal and 16 mm hex size

Detailed Description

Bosch 79104 is part of the Bosch Nickel line, a conventional spark plug family focused on dependable operation and OE-style service life. The nickel-copper construction pairs a copper-core center electrode with a nickel tip to help maintain consistent spark delivery, while the resistor design supports ignition system noise control. This spark plug is engineered to meet or exceed original equipment specifications for nickel-copper core spark plugs, making it a practical choice for routine maintenance on Volkswagen Jetta, Volkswagen Beetle, Volkswagen Golf, and Volkswagen Passat models listed above.

This part cross-references Bosch 79104 for the same application.

Common Issues This Part Can Address

• Hard starting caused by worn spark plug electrodes
• Rough idle from inconsistent ignition firing
• Misfire symptoms related to aged secondary ignition components
• Reduced throttle response from degraded spark quality
• Maintenance replacement for plugs reaching service interval

Installation Notes and Tips

Verify engine application by year, make, and model before installation. Check the specified gap against the vehicle service information and confirm the plug seat type, thread diameter, reach, and heat range match the engine requirements. Inspect ignition coils, boots, and plug wells during service to help avoid repeat misfire concerns. Use proper torque procedures for the flat-seat design to protect the cylinder head and ensure correct sealing.

Quality Assurance

Bosch manufactures this spark plug to OE-level specifications for nickel-copper core applications. The Bosch Nickel product line focuses on conventional ignition service parts that balance durability and value for routine maintenance.