2004 Lexus RX300 3.0L Petrol · KB04 MMF

The most recent MOT test on the 2004 Lexus RX300 occurred in June 2025, where it failed due to a persistent engine malfunction indicated by the MIL (Malfunction Indicator Lamp) and multiple advisories related to oil leaks and worn suspension components. Prior to this, the vehicle passed in July 2024 but failed again in June 2025 with the same engine issue, suggesting a recurring and unresolved mechanical problem. The earlier MOT results from 2021 and 2022 show a pattern where the vehicle initially passed but then failed due to critical brake disc weakness, tyre wear close to legal limits, and power steering leaks, indicating that while some issues were addressed, others persisted or worsened over time. The overall maintenance trend is concerning, with repeated failures linked to the engine and structural components, which could point to underlying wear or a failing system that has not been fully rectified. The recorded mileage of 105,828 miles for a vehicle aged approximately 22 years represents a notably low annual usage rate of around 4,810 miles per year. This suggests either infrequent operation, long periods of inactivity, or a vehicle that has been kept in a garage rather than driven regularly. Such low mileage can mask wear on consumables like brake pads, tyres, and fluids, as these components may not have experienced the same level of stress as in a higher-mileage vehicle. However, prolonged standing can accelerate issues such as corrosion in brake systems, particularly on discs and calipers, which may have contributed to the 2021 MOT failure where brake discs were deemed seriously weakened. Additionally, standing vehicles are more susceptible to oil leaks, as oil can pool and degrade components over time, potentially exacerbating the engine-related failures noted in recent MOTs. Given the recurring engine issues and the critical nature of the 2021 brake disc failures, the prospective buyer should prioritise a thorough inspection of the engine bay for signs of oil leaks, particularly around the valve cover, oil pan, and oil filter housing. Listen for any unusual engine noises, such as knocking or ticking, which could indicate internal wear or failing seals. During a test drive, monitor for power steering fluid leaks or resistance, as the power steering system’s seepage advisories from previous MOTs suggest potential hydraulic component degradation. The suspension should be checked for excessive play in the anti-roll bar linkages, which were severely deteriorated in multiple MOTs, potentially leading to clunking noises over bumps or uneven ride height. Additionally, the brake system should be inspected for binding calipers, corrosion on discs, or uneven wear patterns, as the 2021 failure highlighted serious brake disc compromise. For the Lexus RX300’s age and mileage, the buyer should also conduct a detailed inspection of the tyres for sidewall cracking or perishing, which can occur even with low mileage due to prolonged exposure to the elements. Verify the condition of the 12-volt battery, as standing vehicles can suffer from discharge or internal corrosion, particularly if the alternator output has been compromised by engine issues. Check the fluid levels and condition of the engine oil, brake fluid, coolant, and power steering fluid, noting that fluids degrade over time regardless of mileage. Ensure all service records are up to date, especially for the engine oil change intervals and brake system servicing, as the RX300’s 2004 model year may not have benefited from modern service recommendations. Finally, a professional diagnostic check of the engine control unit (ECU) and the engine’s internal condition should be performed to address the persistent MIL issue, which may require a full engine inspection or replacement if the underlying cause remains unresolved.