The B8.5 SQ5's are generally solid, probably the most reliable / lowest cost of ownership vehicle Audi has made. A few things to note: Water pump and thermostat issues. Plenty of warning (small leaks) before they need to be replaced. About $1000 to replace. PCV under the supercharger. About $1000 to replace. Upgrade your drivetrain mounts for less! FLASH SALE 10% OFF. S4 (B6 & B7 Platforms) Discussion - Buying a 2005 S4 (B6) - I'm currently considering buying a used S4. The B6 seems to fit my needs/wants as well as budget. The car that I'm most closely looking at has about 60k miles. 2. Testing for power to the ECU, PIN 3 has power, but pins 21 and 62 do not. 3. VAG COM cannot find the ECU (As expected when pins 62 and 21 do not have power) 4. Pin 43 has power, VAG COM finds all K-line items except the ECU normally. 5. Disconnecting the battery for 24hours and trying again makes no difference. When the Audi S4 camshaft adjuster seals and valve cover gaskets leak, they typically cause a burning oil smell. The passenger side cam chain tensioner seal is located on the backside of the cylinder head and will drip oil onto the down pipe causing this smell. This Audi S4 leak is best seen through the passenger side wheel well as pictured 1.8T Discussion - N75 wastegate actuator valve explained/symptoms. - alright first off this is my first thread im posting on the audi forums, and ill try to keep posting about every problem i encounter with my TT as long as there isnt posts about the same problem already. the n75 valve is a common topic.. yet i have Carbon Fiber B7 S4 Diffuser! S4 (B6 & B7 Platforms) Discussion - 04 S4 Air conditioning not working - I searched the forums pretty extensively and did not see any relevant threads but forgive me if this subject has been brought up already. I have an 04 S4 that seems to shoot out only hot air of the vents unless I change the temp to low. This causes an air leak into the manifold. Unclip and remove the plastic cover at the front of the engine. You will see the vacuum actuator, control rod and lever at the front of the inlet manifold. Start the engine on idle and watch the lever on the flap valve shaft. The vac unit should activate and move the shaft about 40 degrees clockwise. Symptoms. -Light throttle transmission feels like it is slipping slightly, or torque converter is slipping slightly. The RPMS surge, or bounce 100-200 RPM's back and fourth as the speed increases. -Doesn't actually shift gears, it just sloppily bounces/surges as it accelerates in whatever gear it is in. Vay Tiền Nhanh Chỉ Cần Cmnd.

audi s4 b6 common problems