The brief
The A5 came in for servicing, and at over 120,000 km the accessory belt and its tensioner are due, so those got particular attention in the inspection alongside the usual maintenance. A proper service runs through the whole car: change the oil and filter, replace the air and cabin filters, check the fluids, look over the brakes, suspension and electrical side, test the battery under load, run a diagnostic scan, and eyeball the belts, hoses and underbody. The accessory belt drives the alternator, the aircon and the power steering, and a worn one risks the charging system and more, so a service is exactly when it gets caught and changed before it lets go.
The diagnosis
The visual and diagnostic check went through the lot. The engine oil and filter were due, the air filter and cabin filter were at the end of their life, the brake fluid's water content was a touch high, the battery was beginning to slip on the load test, and the accessory belt was glazed and cracked with the tensioner showing a wobble, both well past their interval. The hoses and underbody checked out clean, no fault codes stored. So it was a full-service list plus a belt-and-tensioner job: replace the wear items, freshen the fluids, do the belt set, and note the battery to watch.
The work
The engine oil was drained and refilled with the correct VAG-spec oil and a new oil filter fitted. The air and cabin filters were replaced, the brake fluid bled and refilled, and the battery load-tested and flagged. The accessory belt and tensioner were swapped for new VW-spec parts, the belt routed correctly and re-tensioned to spec. Coolant and washer fluid topped up, and a full diagnostic scan run. A road test confirmed everything was running cleanly, the belt drive was silent, and nothing was leaking.
The outcome
A full clean bill of health on the A5, with a fresh belt and tensioner. No flags left except the battery to watch, and the car back on the road for another interval. A service is the cheapest insurance there is, and catching the worn belt during the inspection meant it got done before it snapped and took the charging system with it.
