The Audi A4 Sedan, Avant, Cabriolet Repair Manual 2002-2008 by Haynes covers models indicated with 1.8L, 2.0L 4-cylinder turbo engines, and 3.0L, 3.2L V6 engines. Note: this repair manual DOES NOT include diesel engine, S4 or RS4 model info.
Book Excerpt: 2002-2008 Audi A4 Sedan, Avant, Cabriolet Repair Manual GENERAL INFORMATION: ENGINE OVERHAUL

Refer to illustrations 1.1, 1.2, 1.3, 1.4, 1.5 and 1.6 Included is this portion of Chapter 2 are general information and diagnostic testing procedures for determining the overall mechanical condition of your engine. The information ranges from advice concerning preparation for an overhaul and the purchase of replacement parts and/or components to detailed, step-by-step procedures covering removal and installation. The following Sections have been written to help you determine whether your engine needs to be overhauled and how to remove and install it once you?ve determined it needs to be rebuilt. For information concerning in-vehicle engine rebuild, see Chapter 2A or 2B. The Specifications included in this part are general in nature and include only those necessary for testing the oil pressure and engine compression, and bottom-end torque specifications. Refer to Chapter 2A (four-cylinder engines) or 2B (V6 engines) for additional engine Specifications. It?s not always easy to determine when, or if, an engine should be completely overhauled, because a number of factors must be considered. High mileage is not necessarily an indication that an overhaul is needed, while low mileage doesn?t preclude the need for an overhaul. Frequency of servicing is probably the most important consideration. An engine that?s had regular and frequent oil and filter changes, as well as other required maintenance, will most likely give many thousands of miles of reliable service. Conversely, a neglected engine may require an overhaul very early in its service life.

CHECKING THE REFRIGERANT CHARGE

Refer to illustration 3.9

• Warm the engine up to normal operating temperature.
• Place the air conditioning temperature selector at the coldest setting and put the blower at the highest setting.
• After the system reaches operating temperature, feel the larger pipe exiting the evaporator at the firewall. The outlet pipe should be cold (the tubing that leads back to the compressor). If the evaporator outlet pipe is warm, the system probably needs a charge.
• Insert a thermometer in the center air distribution duct (see illustration) while operating the air conditioning system at its maximum setting. The temperature of the outlet air should be 35. to 40 degrees F below the ambient air temperature (down to approximately 40ø F). If the ambient (outside) air temperature is very high, say 110ø F, the duct air temperature may be as high as 60ø F, but generally the air conditioning is 35 to 40ø F cooler than the ambient air.
• Further inspection or testing of the system requires special tools and techniques and is beyond the scope of the home mechanic.

TABLE of CONTENTS: Introduction: Vehicle identification numbers. Buying parts. Safety. Maintenance techniques. Chemical and lubricants, and more.

• Tune-up and routine maintenance
• 1.8L turbocharged four-cylinder engine
• 2.0L turbocharged four-cylinder engine
• 3.0L V6 engine
• 3.2L V6 engine
• General engine overhaul procedures
• Cooling, heating and air-conditioning systems
• Fuel and exhaust systems
• Engine electrical systems
• Emissions control systems
• 5-speed manual transmission
• 6-speed manual transmission
• 5-speed automatic transmission
• 6-speed automatic transmission
• Continuously Variable Transmission (CVT)
• Driveline
• Brakes (ABS)
• Suspension and steering systems
• Body: sedan, wagon, convertible
• Chassis electrical system
• Wiring diagrams

Subject: 2002, 2003, 2004, 2005, 2006, 2007, 2008 Audi A4 Sedan, Avant, Cabriolet service, maintenance, repair. ISBN-10: 156392837X | ISBN-13: 9781563928376 | Haynes 15030