The launch year of the original A4 brought a modern, well-built compact executive car. Now over 30 years old, every B5 needs careful checks for suspension wear, water ingress, and 1.8T timing belt history.
The battery tray sits in a bulkhead plenum chamber with two one-way rubber drain grommets that clog with road debris and pine needles. Trapped water submerges the brake servo, drawing water into the vacuum line and rusting the servo shell.
The longitudinally mounted 1.8T has a relatively small 3.5-litre oil capacity. Following factory long-life variable service schedules causes severe oil coking that chokes the oil pump pickup pipe gauze, starving the camshafts and turbo.
The four-link front suspension features long steel pinch bolts through the aluminum hub carriers that seize solid from galvanic corrosion and road salt, while the upper and lower control arm rubber bushes split and knock.
The B5 utilizes a vacuum pump inside the right-hand boot wing to operate door locks and fuel flap. Over time, the brittle graphite impeller blades inside the motor housing shatter, leaving the pump buzzing without locking doors.