2020 Audi A4 Technik 35 TDI S-A 2.0L Diesel · LS20 AXZ

The most recent MOT test on the 2020 Audi A4 Technik 35 TDI S-A, conducted on 2026-07-23, resulted in a clean pass with no defects recorded, marking a positive conclusion to a maintenance history that has otherwise shown a consistent trend of passing tests. While the advisory from 2024 regarding corrosion in the rear lower coil spring mountings—both near and offside—suggests a recurring issue that the vehicle has managed to maintain without immediate failure, it does indicate a gradual wear progression that could escalate if left unaddressed. The absence of failures in the intervening MOTs implies that the vehicle has either been serviced promptly to mitigate these concerns or that the corrosion is not yet severe enough to compromise structural integrity or ride quality. The advisory from 2023 about a near-side rear tyre nail, while not critical, highlights a minor puncture that should be monitored to prevent further damage to the tread or sidewall. The recorded mileage of 84,584 miles for a 2020 model represents a relatively high annual usage rate of approximately 14,097 miles per year, which is notably elevated for its age. Such mileage accumulation typically accelerates wear on consumables like brake pads, suspension components, and drivetrain elements, as well as on fluids such as brake fluid and differential oil, which degrade more rapidly under sustained high stress. The absence of significant service intervals or long periods of inactivity could also contribute to issues like brake disc corrosion from standing, particularly if the vehicle was frequently driven in stop-start traffic or on hilly terrain. Additionally, the high mileage may suggest that the vehicle has undergone rigorous use, potentially exposing it to more aggressive driving conditions that could exacerbate wear on suspension bushes, exhaust components, and tyre tread durability. For a prospective buyer, the most critical areas to inspect during a physical examination of this vehicle are the rear suspension coil springs and their mountings, given the recurring corrosion advisories. The symptoms of compromised coil springs—such as a noticeable clunking or rattling when driving over bumps, uneven ride height, or excessive play in the rear suspension—should be carefully monitored. If the corrosion has progressed to the point of spring failure, it could lead to structural instability, uneven tyre wear, or even a complete suspension collapse, which would be catastrophic. The buyer should also verify the condition of the rear brake discs and linings, as high-mileage vehicles are prone to corrosion from moisture exposure, particularly if the vehicle has been stored in damp conditions or driven frequently in wet conditions. Binding calipers or discs may indicate standing corrosion, which can cause uneven braking performance or require replacement. Beyond the suspension and braking systems, the buyer should conduct a thorough inspection of the tyre condition, focusing on sidewall perishing, which can occur even at moderate mileage due to age-related degradation of the rubber compound. The tyre tread depth should be checked for wear patterns that may indicate alignment or suspension issues, and any signs of sidewall damage or bulges should be noted, as these can signal underlying mechanical problems. The vehicle’s 12V battery should be tested for health, especially given the high annual mileage, as prolonged driving can strain the electrical system. Additionally, the fluid levels—particularly the brake fluid, differential oil, and coolant—should be checked for contamination or degradation, with a recommendation to replace them according to the manufacturer’s service schedule, which for a 35 TDI typically includes brake fluid every 2–3 years and differential oil every 60,000–100,000 miles. Finally, the exhaust emissions system should be reviewed for any signs of leaks or component failure, as the TDI’s common-rail injection system is prone to wear, and a failing catalytic converter or oxygen sensor could lead to poor fuel economy and potential MOT failure if not addressed. The buyer should also verify the service book for any recorded maintenance, particularly for the timing belt replacement, which for this engine model is critical and should have been performed at the recommended interval of around 100,000–120,000 miles.