The Audi A4 TDI is a popular compact executive car from the German manufacturer, Audi. Since Audi is a subsidiary of Volkswagen, Audi and Volkswagen engine technology is often similar. The TDI represents the Turbocharged Direct Injection engine, a diesel engine with upgraded power that uses direct injector technology originally designed by Volkswagen. TDI technology allows for greater engine efficiency and higher outputs in power. Audi A4 TDI engines use a rubber belt with teeth to drive the camshaft. The timing belt ought to be replaced before its actual failure to save money, typically every 60,000 miles.
Locate the band clamps. These should be on the oil filtration system of the engine. Loosen the band clamps using the flat band clamp pliers to remove the intake tube of the intake manifold.
Unplug the connector of the coolant tank. The coolant tank is the plastic container with water that cools the engine. Undo the clamp on the overflow tube using a pair of regular pliers and pull off the overflow tube. Push the overflow tube to under the firewall to secure it and insert a cap to the open end of the coolant tank.
Remove the screws holding the coolant tank using a Philips head screw driver. Remove the allen bolt on the power steering using the 5mm 3/8 inch drive allen socket and extension then unplug the fuel lines from the filter. Raise the power steering reservoir and gently remove the coolant tank. Allow the coolant tank to hang from the side of the car.
Remove the upper cover of the timing belt. Remove the rear and front allen bolts of the valve cover using the 5mm 3/8 inch drive allen socket and extension. Do not remove the two allen bolts that are next to the oil filler cap. Lift and remove the valve cover. Locate the first two lobes on the camshaft and turn them to the up position.
Locate and remove the vacuum line (this should be running under the vacuum pump). Remove the lower and upper 10mm nuts using a ¼ inch drive deep socket. Using the 10mmm 45 degree offset wrench remove the support brackets of the vacuum line. Remove the front, rear and lower bolts of the vacuum pump using the 13mm deep socket. Remove and bend the vacuum pump out of the way.
Lift the car using the jack stands and the hydraulic lift. Crawl under the car from the passenger side and locate the turbo compressor outlet pipe. This should be at the back of the engine. Remove the spring on the turbo compressor using the flat clamp pliers and pull off the hose. Remove the nut on the turbo compressor using a 10mm socket. Remove the whole duct assembly by removing the clamp on the intercooler using the flat clamp pliers.
Remove the washer nuts of the engine side panel using a long screwdriver and remove the panel. Relieve the tension on the belt tensioner using the 41831 serpentine belt tensioner tool and remove the belt.
From the upper side of the car, rotate the engine clockwise using the 30036 camshaft holding bar to a 'lobes up' position. The groove in the cam pulley will be aligned to the valve in the cover deck.
Insert the 3418 camshaft setting bar into the groove at the end of the camshaft. Locate the timing mark on the flywheel (a circled A with minus signs on either side).
Remove the engine mount alignment plate using a 13mm deep socket with extension. The lower bolts can be removed using a 16mm and ½ inch drive socket.
Lift the engine so that it is an inch off the car frame by placing a block of wood on the jack on the passenger side of the vehicle. Remove the remaining engine mount bolts using the ½ inch 18mm socket and remove the engine mount.
Raise the engine on the jack further to expose the mount bracket hole. Use a 3/8 inch deep socket to remove the centre and front bolts. Lower the engine and remove the four allen bolts of the harmonic balancer using the 3/8 inch deep drive ratchet. Remove the harmonic balancer.
Loosen the bolts on the lower engine mount using the 3/8 inch deep drive ratchet and 16mm socket. Remove the timing belt cover plate bolts using a ¼ deep drive ratchet and 10mm socket. Then remove the loosened bolts of the lower engine mount. Remove the cover plate of the timing belt.
Remove the nut on the tensioner. Place a 2587 two pin spanner wrench on the tensioner and rotate anticlockwise. Loosen the bolts on the camshaft pulley using a 19mm 1/3 inch drive socket. Install the T40001 puller set in the camshaft pulley snaps and remove the camshaft pulley bolt. Remove the camshaft pulley.
Remove the old tensioner. Slide the old timing belt between the engine mount and blocks to remove the belt. Slide the new belt between the engine mount and blocks and around the pulleys. Install the new tensioner and reassemble the engine. Double check to see if the flywheel is at TDC (the timing mark should be just visible).