Bosch Ignition Rotor – 04170 The Bosch 04170 is a high-performance ignition rotor designed for modern-classic European and select import vehicles. As a core component of the distributor system, this rotor transfers high-voltage current from the ignition coil to the individual spark plug terminals. Engineered specifically for electronic ignition systems, the 04170 ensures precise timing and a strong, consistent spark necessary for maintaining fuel efficiency and engine power. Constructed with a heavy-duty brass contact tip, this rotor offers superior electrical flow and resistance to the "arc-erosion" that typically wears down cheaper aluminum components. It features an integrated resistor to suppress radio frequency interference (RFI), protecting sensitive engine sensors and onboard electronics from electrical noise. Detailed Vehicle Compatibility Audi 4000: 1985, 1986, 1987 Audi 80 / 80 Quattro: 1988, 1989, 1990, 1991, 1992 Audi 90 / 90 Quattro: 1988, 1989, 1990, 1991 Hyundai Scoupe: 1993, 1994 VW Cabrio: 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002 VW Cabriolet: 1990, 1991, 1992, 1993 VW Corrado: 1990, 1991, 1992 VW EuroVan: 1992, 1993, 1994, 1995, 1996 VW Fox: 1991, 1992, 1993 VW Golf: 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999 VW Jetta: 1985, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999 VW Passat: 1990, 1991, 1992, 1993, 1994, 1995, 1996 VW Scirocco: 1986, 1987, 1988 VW Vanagon: 1986, 1987, 1988, 1989, 1990, 1991 Volvo 240 / 244 / 245: 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993 Volvo 940: 1995 Product Highlights & Features Brass Contact Surface: Delivers maximum energy to the spark plugs while resisting the pitting and corrosion that leads to ignition failure. Precision Dielectric Housing: Prevents high-voltage "leakage" to the distributor shaft, ensuring the spark goes exactly where it is intended. RFI Suppression Resistor: Prevents electrical interference with the vehicle's ECU, radio, and other sensitive digital components. OEM Fit and Quality: Manufactured by Bosch to meet the exact tolerances required for the widely used 2.0L ABA and Volvo B230 engines. Technical Specifications Part Number: 04170 Interchange: 052-905-225C Resistor Value: 1k Ohm Compatibility: Electronic Ignition Distributors Installation & Maintenance Tips Alignment is Key: Ensure the internal notch on the rotor is perfectly lined up with the groove on the distributor shaft. Press down firmly until seated; a loose rotor can destroy the distributor cap. Check the Cap: When replacing the rotor, always inspect the distributor cap terminals for heavy oxidation. Replacing both as a set is recommended for peak performance. Moisture Inspection: If you experience misfires in damp weather, check the rotor for "carbon tracking"—tiny black lines on the body that indicate current is leaking to ground. Service Interval: For high-mileage daily drivers, inspect the rotor every 30,000 miles to ensure the brass tip hasn't thinned out.
