Genuine 1993 Audi 100 Timing Belt

1993 Audi 100 Timing Belt Parts and Q&A

• Q: How does the toothed timing belt drive the camshaft, fuel injection pump, and intermediate shaft, and what steps should be taken to ensure its proper maintenance on 1993 Audi 100?

  A: The toothed timing belt mostly drives the camshaft, fuel injection pump and intermediate shafts and any slippage or breakage may interfere with valve timing and may result in piston-to-valve contact and severe engine damage. It is thus important to make sure that timing belt is tightened properly and also that it is checked regularly to check whether it is worn or spoilt. Start by unplugging the battery and getting rid of the engine top cover. Open the upper section of timing belt outer cover by prising open metal spring clips and removing screws and lifting off the cover of the engine. Disconnect the auxiliary drivebelts, loosen, and remove screws and remove the coolant pump pulley. Switch the engine to TDC on cylinder No 1 with the help of alignment marks, and then loosen the ribbed auxiliary belt pulley and ensure that the engine stays at TDC. Loose the timing belt lower cover and take the tension off the timing belt by slacking the tensioner mounting nut. Check the belt with manufacturer marks which will show which way to turn it and in case it can be used, it is important to reassemble them in the same position to avoid excessive wear. Slide the belt off the sprockets very carefully not to twist or kink. Check the belt to ensure that it is not contaminated with coolant or lubricant and look at its wear or any form of damage and replace it where needed, particularly when its run length has already attained that which is stipulated by the manufacturer. In case the timing belt is not going to be reinstated at the moment, tie a warning sign on the steering wheel to avoid the possibility of accidentally starting the engine. In refitting, make sure that crankshaft and camshaft are positioned to TDC in cylinder No 1, and then loosen the camshaft sprocket bolt and disengage the sprocket on the camshaft taper mounting. Install the timing belt by looping it loosely underneath the crankshaft sprocket and noting the direction markings on the belt and ensure that the teeth on the belt pinch into the teeth on the crankshaft sprocket before passing the belt over the camshaft and injection pump sprockets. Slide the flat side of the belt across the intermediate shaft roller and pulley and never bend or twist the belt too much. Take out the locking pin of the fuel injection pump sprocket, and be sure that the left-hand pull of the belt is taut. Turn tensioner clockwise till the notch and raised tab are aligned, tighten the tensioner locknut to the required torque. Align the tensioner wheel hub alignment pointers and check their movement relative to one another when they are pressed on the timing belt. Make sure that the crankshaft is still in position at TDC on cylinder number 1, and then tighten the camshaft sprocket bolt with the unit stationary. Disengage the camshaft lock bar and turn the crankshaft 2 full turns and reset to TDC on No 1 cylinder and fuel injection pump sprocket locking pin can still be put in. Install the timing belt bottom cover again and secure it, and the top cover too and secure again. Install the crankshaft auxiliary belt pulley and auxiliary pump pulley, attaching the retaining screws to the correct torque, and lastly install and tighten the auxiliary drivebelts, and then reconnect the battery and recheck the fuel injection pump timing.