Timing marks for valve timing (Audi A6 C4)

The crankshaft, camshaft and intermediate shaft sprockets are driven by the timing belt and rotate in phase.

If the sprockets are out of phase, the valves will touch the pistons as the crankshaft rotates.

The top dead center is taken to be the highest point reached by piston N1 during the compression stroke.

Execution order

1. To set piston N1 to TDC, remove the camshaft cover and drive belts. Remove the upper timing belt cover. Unscrew the glow plugs.



2. Unscrew the inspection hole plug in the gearbox.



3. Align the marks by turning the crankshaft. The synchronization mark on the flywheel (arrow) aligns with the protrusion on the gearbox casing.





4. Using special tools, lock the camshaft.





5. Center the locked camshaft using feeler gauges.



6. Lock the fuel pump sprocket. Now, piston N1 is at TDC.

[The full version is posted on the resource «AudiManual.ru»]