The VW Passat™ 1998-2005, Audi A4 1996-2001 Repair Manual by Chilton, covers all U.S. and Canadian models of Volkswagen Passat and Audi A4, 4-door sedan and 5-door wagon body styles.
Book Excerpt: 1998-2005 VW Passat, 1996-2001 Audi A4 Repair Manual
GENERAL ENGINE OVERHAUL PROCEDURES
CRANKSHAFT | REMOVAL
FUEL AND EXHAUST SYSTEMS
(Refer to illustrations 14.1, 14.3 and 14.4)
NOTE: The crankshaft can be removed only after the engine has been removed from the vehicle. It's assumed the flywheel/drive plate, timing belt, oil pan, oil pump, the front and rear oil seal housings and the piston/connecting rod assemblies have already been removed.
- Before the crankshaft is removed, check the endplay. Mount a dial indicator with the stem in line with the crankshaft and touching the snout of the crank (see illustration).
- Push the crankshaft all the way to the rear and zero the dial indicator. Next, pry the crankshaft to the front as far as possible and check the reading on the dial indicator. The distance it moves is the endplay. If it's greater than listed in this Chapter's Specifications, check the crankshaft thrust surfaces for wear. If no wear is evident, new main bearings should correct the endplay.
- If a dial indicator isn't available, feeler gauges can be used. Gently pry or push the crankshaft all the way to the front of the engine.
Slip feeler gauges between the crankshaft and the front face of the thrust main bearing to determine the clearance (see illustration).
NOTE: The thrust bearing is located at the number three main bearing cap on four-cylinder engines and at the number four main bearing cap an V6 engines.
- Check the main bearing caps to see if they're marked to indicate their locations. They should be numbered consecutively from the front of the engine to the rear (see illustration). If they aren't, mark them with number stamping dies or a center punch.
Main bearing caps generally have a cast-in arrow, which points to the front of the engine.
Loosen the main bearing cap bolts 1/4-turn at a time each, until they can be removed by hand.
Note if any stud bolts are used and make sure they are returned to their original locations when the crankshaft is reinstalled.
- Gently tap the caps with a soft-face hammer, then separate them from the engine block. If necessary, use the bolts as levers to remove the caps.
Try not to drop the bearing inserts if they come out with the caps.
TURBOCHARGER AND INTERCOOLER (FOUR-CYLINDER ENGINE) | CHECK AND REPLACEMENT
- The turbocharger is a precision component which can be severely damaged by a lack of lubrication or from foreign material entering the air intake duct.
Turbocharger failure may be indicated by poor engine performance, blue/gray exhaust smoke or unusual noises from the turbocharger. If a turbocharger failure is suspected, check the following areas:
- Check the intake air duct for looseness or damage. Make sure there are no restrictions in the air intake system, or a dirty air filter element or damaged intercooler.
- Check the system vacuum hoses for restrictions or damage.
- Check the system wiring for damage and electrical connectors for looseness or corrosion.
- Make sure the waste gate actuator linkage is not binding.
- Check the exhaust system for damage or restrictions.
- Check the lubricating oil supply and drain back lines for damage or restrictions.
- Check the coolant supply and return lines for damage and restrictions.
- If the turbocharger requires replacement due to failure, be sure to replace the engine oil and filter (see Chapter 1 for complete information).
- Complete diagnosis of the turbocharger and control system require special techniques and equipment. If the previous checks fail to identify the problem, take the vehicle to a dealership service department or other properly equipped repair facility for diagnosis.
Subject: 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005 VW Passat and 1996, 1997, 1998, 1999, 2000, 2001 Audi A4 service, maintenance, repair. ISBN-10: 1563927489 | ISBN-13: 9781563927485 | Chilton 70700