2008 Audi A4 Quattro Repair and Maintenance
A guide to problems, costs, maintenance and repair for your 2008 Audi A4 Quattro
Never overpay. Check prices with our estimator
Verified by mechanics, reported by drivers like you
Ask a mechanic in our community
2008 Audi A4 Quattro ProblemsDecreased Power and Fuel Economy from Carbon Buildup
The 2006-2016 Audi A4 Quattro uses FSI and TFSI direct injection engines. These engines are subject to carbon buildup in the intake system which can cause power loss, OBD codes and a check engine light, and a rough idle. In normal engines, the engine is cleaned by the gasoline flowing through the injectors and into the intake system, however, since the A4 Quattro uses direct injection, gasoline does not flow through common carbon buildup areas.
The solution is to remove the intake manifold and professionally clean the intake manifold, intake ports on the cylinder head, and the intake valves. This may need to be done in as few as 20,000 miles.
Popping sounds from the rear of the vehicle may be heard moments after starting the engine, or when slowing to a stop. This noise is from the leak detection pump filling the fuel tank with air, and releasing to retest the system when it finds a fault. The sequence of faults identifying this issue are as follows:
- Succession of loud pops from rear of vehicle
- Pops go away, and fuel economy decreases
- Check engine light illuminatesT
- OBD trouble code P2404 and/or P0441 is stored
- Engine will not start after refueling (must crank for over 30 seconds)
- Vibration when slowing to a stop
The cause is a valve which is mounted on the front of the intake manifold, commonly called the N80 valve, or EVAP system purge valve. The valve is designed to open under specific circumstances, but a worn valve will remain open at all times, preventing the pressurization of the fuel tank.
Correction of the issue is to replace the N80 valve with the latest revision.
A turbocharged engine looses power if the turbocharging system has a leak (boost leak). The most common turbo boost leak for the A4 Quattro 2.0 FSI is a torn rubber diaphragm on the diverter valve, which is intended to open only if pressure gets too high. Common symptoms are increased turbo noise when letting off of the gas pedal, and power loss.
If there is a turbocharging system leak, the system will need to be inspected, and the defective seals and/or valve will require replacement.
2008 Audi A4 Quattro Questionsaudi dealer is charging me $1,186 to replace fuel pump and injector. Fair price? (1 answer)
The mechanic says the valve cover is causing the leak, NOT the valve cover gasket. The cost will be $800, and I think this includes both the valve cover and the valve cover gasket. Does this seem right? Diagnosis says: "Valve cover is leaking oil. Breather system needs replacing with the...
S line model
2008 Audi A4 Quattro RecallsAir Bag Control Unit Fails
The air bag control unit may corrode and fail. Dealers will replace the air bag control unit free of charge to resolve the concern.