NGK 3964 Spark Plug

NGK 3964 Standard Spark Plug for Volkswagen

NGK 3964 is a standard spark plug built for direct-service ignition replacement in select Volkswagen applications. It uses a copper center electrode core, nickel center and ground electrode tips, and a semi-surface discharge ground design to support consistent spark delivery in the specified OE-style applications.

Key Features

• NGK Standard Spark Plug, part number 3964
• Stock number 3964; NGK part number BKR5EKU
• 14 mm thread diameter with 0.75 in. reach and flat seat
• Pre-gapped to 0.028 in. for listed Volkswagen applications
• Copper core center electrode for stable conductivity
• Nickel center and ground electrode tip materials
• Semi-surface discharge ground electrode design with two ground electrodes
• 5 k? resistance and non-removable nut terminal
• Heat range 5 with 5/8 in. hex size

Product Details

NGK is a long-established OE supplier with broad coverage across domestic and import vehicles, and this Standard Spark Plug line is built around original-equipment-style service requirements. Part number 3964 is specified for select Volkswagen EuroVan, Golf, Jetta, Passat, and Corrado applications, including 1992-2003 Volkswagen models listed in the fitment data. For Volkswagen Golf and Jetta spark plug replacement, this plug matches the stated 0.028 in. gap and OE-equivalent service expectations.

This part cross-references CSF 3964 for the same application.

What It Helps Address

• Hard starting caused by worn or fouled spark plugs
• Rough idle from inconsistent ignition output
• Misfire conditions tied to aged plug electrodes
• Reduced throttle response from weak spark delivery
• Service interval replacement on listed Volkswagen ignition systems

Installation Notes

Verify the engine application before installation and confirm the plug gap is set to 0.028 in. for the listed vehicles. Check thread reach, seat type, and terminal style against the original plug before service. Use proper torque procedures and inspect ignition wires or coil components during spark plug replacement on Volkswagen EuroVan, Golf, Jetta, Passat, and Corrado models.

Quality Assurance

NGK manufactures spark plugs to OE standards and supplies ignition components for a wide range of automotive applications. The brand’s North American OE legacy and manufacturing focus support consistent fit and service performance in the applications listed here.