Routine timing belt service has turned into an ongoing troubleshoot for why it now sounds like a diesel running. Have had the job redone twice with all new parts to no avail. Going back to the dealer this month for them to replace the belt again because they think there is some issue with it.
A/C head failed. Very simple to replace on the 92-84 cars.
Hydraulic leak proving hard to trace. Rack was replaced at about 70K according to records.
Battery discharge problem finally traced to corroded main ground to chassis.
Motor and transmission mounts replaced.
Speed sensor failed.
Cruise control is now intermittent.
The usual Audi window switch failure. Easy to fix once you know how.
Power recline for driver's seat failed.
Mass airflow sensor failed. Easy fix, expensive part.