2004 Porsche 911 3.6L Petrol · YN04 MLF

The most recent MOT test on 2026-07-02 resulted in a pass, though it included several advisories that suggest ongoing wear and potential long-term concerns. The overall maintenance trend appears to be stable rather than worsening, as the vehicle has passed MOTs in 2024 and 2025 while encountering recurring issues—particularly with brake pipe corrosion, anti-roll bar bush wear, and tyre wear—rather than failing due to critical mechanical failures. However, the presence of a failed MOT in 2026-06-29, which highlighted an engine MIL and emissions failure, indicates that deeper diagnostics are necessary to address persistent catalytic converter or sensor-related problems. The fact that the vehicle has not failed on structural integrity, exhaust emissions, or drivetrain components in recent years suggests that while consumables and wear items are being managed, the underlying engine and emissions systems require closer scrutiny. The vehicle’s recorded mileage of 186,038 miles at 22 years old represents a moderate annual usage rate of approximately 8,456 miles per year, which is typical for a high-performance Porsche of this age. Such mileage does not necessarily indicate excessive wear if the vehicle has been maintained with reasonable frequency, but it does imply that all consumable items—such as brake pads, suspension bushings, and tyres—have experienced significant usage. The consistent advisories on tyre wear, particularly on the near-side front and rear tyres nearing legal limits and showing edge wear or perishing, suggest that the vehicle has been driven with some exposure to rough roads or aggressive cornering, which accelerates tyre degradation. Additionally, the presence of multiple advisories on anti-roll bar bush wear and brake pipe corrosion indicates that the suspension and braking systems have been subjected to prolonged stress, warranting a thorough inspection of these components for long-term reliability. For a prospective buyer, the most critical areas to inspect during a physical examination include the brake system, suspension, and tyre condition. The recurring advisories on brake pipe corrosion—particularly the near-side front pipe covered in grease—should prompt a check for internal corrosion or leaks, as this could lead to brake fluid contamination or system failure. Listen for uneven brake pedal travel or a spongy feel when applying the brakes, and visually inspect brake discs for excessive pitting or warping, which may indicate overheating or binding calipers. The anti-roll bar bush wear advisories suggest that the suspension is showing signs of fatigue; examine the bushings for excessive play or cracks, and check for clunking noises when driving over bumps, especially at speed. The tyre advisories necessitate a full inspection for sidewall cracks, perishing rubber, or uneven wear patterns, as these can compromise handling and safety. Beyond the mechanical checks, the vehicle’s age and mileage warrant attention to fluid condition and standing corrosion. Given the coolant leak advisory from 2024, verify the coolant system for leaks, corrosion in the radiator or hoses, and ensure the coolant is fresh and properly mixed with water—old coolant can degrade seals and cause internal leaks. The engine oil should be checked for contamination or sludge, as the 2026-06-29 oil leak advisory may indicate worn seals or gaskets, which could lead to further oil loss or dilution of coolant. Finally, the battery health should be assessed, as a 22-year-old Porsche may have a weakened 12V system, especially if the vehicle has been stored for extended periods. Test the battery voltage at a cold start and listen for any unusual electrical whining or clicking, which could signal a failing starter or alternator. If the vehicle has been driven infrequently, check for standing corrosion on the chassis, especially around the wheel arches, exhaust manifolds, and underbody, as moisture and road salt can accelerate rust progression. Prioritise a full service history review to confirm that all scheduled maintenance—such as timing belt replacement (if applicable), spark plug changes, and fluid top-ups—has been documented, as this will provide clarity on the vehicle’s long-term maintenance record.