Withdrawal
1. Loosen the cover bolts located on the back of the engine to gain access to the fuel pump drive belt.
2. Remove the glow plugs to make turning the engine easier.
3. With the socket on the crankshaft pulley bolt, slowly turn the crankshaft clockwise until the TDC alignment mark on the edge of the flywheel/drive plate aligns with the alignment rib on the clutch housing and the alignment mark on the fuel pump sprocket is aligned with the mark on the pump housing. The moment when the number 1 piston begins to move in the cylinder. can be identified by the sound of air escaping from the No. 1 glow plug hole. Alternatively, remove the camshaft cover so that the lobes of cylinder #1 are visible. When they are both pointing up, the number 1 piston is at TDC.
Note: Due to the dynamic method of setting the injection timing (the pump rotates on the mount to make fine adjustments) The TDC mark on the fuel pump pulley may not align exactly with the mark on the pump housing. In this case, make a new rosary to use when installing the drive belt.
Engines 1T
Note: The tensioner is provided with brackets for the spring needed to tension the drive belt during installation. The spring is actually a special Audi tool, inaccessible to a car enthusiast.
4. Mark the tension on the pump drive belt to facilitate subsequent installation. Loosen the nut on the belt tensioner to loosen it. Remove the belt from the fuel pump sprockets and camshaft (see illustrations).
Engines 3D
5. On 3D engines, block the fuel pump sprocket by inserting a pin through its mounting hole into the pump housing. Block the sprocket at the rear end of the camshaft using a suitable tool (see chapter 6), then unscrew the mounting bolt, and remove the sprocket and drive belt. Remove the belt from the fuel pump sprocket.
Inspection
6. If the belt is contaminated with coolant or grease, find the source and eliminate the cause. Inspect the belt for damage and signs of wear, especially around the leading edges of its teeth. Replace the belt if there is any doubt about its condition; the cost of replacing the belt is negligible compared to the cost of repairing the engine, which would be required if the belt burst on the move. The belt must also be replaced if the vehicle has traveled the distance specified by the manufacturer since it was installed.
Installation
Engines 1T
7. Position the tensioner with the lever up so that the tensioner presses against the drive belt when the spring is attached. The nut must be loosened one full turn in order for the tensioner to move freely.
8. Make sure the TDC timing marks on flywheel/drive plate and fuel pump are still aligned
9. Install the drive belt on the camshaft and fuel pump sprockets and route it over the intermediate roller and tensioner pulley. The lower run of the belt must be tensioned and the slack must be located below the tension mechanism.
10. If possible, attach a special spring to the tensioner lever and tension the drive belt. If a special spring is not available, have an assistant attach a steelyard to the arm and apply a pull of approximately 2.5 kg (see illustration). While holding the steelyard spring in this position, rotate the crankshaft about half a turn clockwise, then tighten the tensioner nut to the specified torque.
11. Check and, if necessary, adjust the injection timing as described in Section 3A.
12. Screw in the glow plugs, then install the drive belt cover and tighten the bolts.
Engines 3D
13. Route the drive belt over the fuel pump sprocket, then place the camshaft sprocket in the belt and install it on the shaft.
14. Insert the bolt and tighten it with a force of 50 Nm while holding the sprocket stationary (see chapter 6). The locking pin is still inserted into the fuel pump sprocket so it is important not to tighten the drive belt while tightening the bolt.
15. Loosen the bolt about half a turn and make sure the sprocket turns freely on the camshaft.
16. Check drive belt tension. There is a special Audi tool designed for this purpose. If the tool is not available, be guided by the fact that with the correct tension in the middle of the run between the sprockets of the camshaft and the fuel pump, the belt can only be twisted by 90°with your fingers.
17. Make sure the TDC alignment marks are still aligned, then tighten the camshaft sprocket bolt to the specified torque while holding the sprocket stationary.
18. If the drive belt tension is incorrect, move the fuel pump bracket to the cylinder block by loosening its bolts. At the end of the adjustment, tighten the bolts with the tightening torque specified in the Specifications, and then repeat the belt tensioning procedure.
19. Check and, if necessary, adjust the injection timing as described in Section FOR.
20. Screw in the glow plugs, then install the drive belt cover and tighten the bolts.
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