Timing belt replacement Audi A6 4F, BRE engine 2.0 TDI PD (Articles)

Tools and necessary parts for timing belt replacement.

Those who have already replaced the timing belt on various 1.9 TDI engines with a distributor injection pump may be inclined to try starting without using a crankshaft lock, instead opting to look inside the transmission bell housing and locate the TDC (Top Dead Center) mark on the flywheel.

Unfortunately, this reveals that the inspection hole on the Audi A6 4F with a GYX (6-speed manual transmission) is a) very small, b) poorly positioned, and c) you can't really see anything through it anyway.
-> For 2.0 TDI PD 16V engines, investing in a crankshaft locking tool is highly recommended to allow for the timing belt replacement to be performed within a reasonable timeframe.

So, when buying a timing belt sprocket (KW-Stopp), it's often available in a set that includes a matching locking pin for the camshaft gears. Since you ideally need two locking pins, you can also use a Torx screw of approximately the same diameter for the second camshaft gear.
Unfortunately, the purchased marking pin lost its black plastic knob due to poor quality, so only a nut is screwed on in the pictures shown here.

The two-hole motherboard standoffs may not be necessary depending on the mounting holes, but my new one conveniently had an extra hole for a hex socket screw.

A small mirror can be very useful for checking the correct installation of the crankshaft stop.

Since the timing belt replacement is required every 120,000 km for the BRE engine, a new water pump was also purchased and installed at the same time, as it is driven by the timing belt. It's advisable to replace the water pump proactively, as it only requires three additional screws.

In the example, a timing belt kit with water pump from Contitech (CT1051 WP1) was used.

The final check of the synchronization angle between the crankshaft and camshaft was performed using VCDS-RKS.


Preparatory work, front-end service provision

- Remove the air filter cover/air intake snorkel.
- Remove the underbody cover from the engine compartment and remove the engine cover.
- Remove the plastic cover at the top of the door frame by starting on the side and pulling it forward from the tab, then unclip the cover on the grill frame and lift it upwards.
- Remove the fender liners attached to the bumper (using one Torx screw) and fold them inwards.
- Loosen the bumper at the three lateral Torx screws on the locking carrier inside the wheel well. Detach the locking carrier from below using one Torx screw to release it from the metal bracket attached to the longitudinal member.
- Remove the bumper from the castle bracket by unscrewing one M10 nut from the back, underneath the headlight on each side. Unscrew the top of the bumper from the grille (using a Torx screwdriver) on the left, center, and right sides.
- Have a second person hold the bumper in place or secure it to the door frame with wire.
- Disconnect the side bumper at the transition to the fender and unplug the connectors for the fog lights. The side locking mechanism/attachment of the bumper to the fender is released by pulling in the direction of travel!
- Pull the bumper forward.
- Mark the position of the headlights relative to the fenders.
- Remove the headlights by unscrewing them from the two front screws on the door frame.
- Mark the position of the gatekeeper.
- Almost completely unscrew the fixing screws of the lock carrier and pull the lock carrier forward.
- Loosen the V-ribbed belt by adjusting the tensioner and remove the belt. Mark the direction of rotation beforehand if it is to be reused.
- Loosen the four internal hex screws on the pulley for the ribbed belt at the crankshaft and remove the pulley. Note that the ribbed belt pulley only fits in one position; pay attention to the hole and protrusion on the timing sprocket!
- Unclip the upper timing belt cover and pull it upwards.
- Remove the timing belt cover plates.


Fix the crankshaft at TDC (Top Dead Center) with the camshaft gears positioned at their designated marks.

- Kurbelwelle in Laufrichtung auf OT drehen und Kurbelwellenstopp aufschieben, wenn die Nockenwellenräder "richtig" stehen. See image.
- Mark the camshaft gears with an Edding marker.
- When standing in front of the hood, disconnect the right camshaft wheel.
- The left camshaft gear does not need to be locked, but those who are more cautious can do so if they wish.


Replace timing belt, water pump, and tensioner pulleys.

- Release and remove the tensioning roller.
- Loosen and remove the large idler pulley.
- Remove the timing belt.
- Replace a minor leadership role.
- Ensure the cooling system is depressurized (usually not necessary, but be sure to check), and remove the mounting screws of the water pump.
- Remember to place a bucket underneath and note the position of the water pump.
- Position the new water pump next to the old one, then loosen the old one by twisting and remove it. Quickly insert the new one. If you're fast enough, only a small amount of coolant will be lost.


Install a new timing belt.

The trick is to install the new timing belt in a way that everything aligns properly after adjusting the tensioner. Here's how to do it:
- Loosely attach the new tensioner pulley. Make sure that its position allows for maximum slack in the timing belt and that the guide pin is properly aligned.
- Loosen the left camshaft sprocket mounting bolt.
- Remove the crankshaft lock from its locking position and rotate the crankshaft exactly one tooth counterclockwise.
- Install the new timing belt and then temporarily (loosely) mount the large idler pulley. Place the timing belt so that it starts at the right camshaft wheel, then to the timing belt sprocket, and then over the unfixed left camshaft wheel.
- Pay attention to the alignment of the camshaft gears relative to each other.
- Tension the tensioning roller to a moderate level, paying attention to the indicator finger.
- Now rotate the crankshaft back to Top Dead Center (TDC), and secure the crankshaft stopper.
- Check all positions, including the left and right camshaft gears and the crankshaft sprocket.
- Everything is fine, remove the fixings and rotate the crankshaft two revolutions in the direction of rotation.
- Check all positions, including the left and right camshaft gears and the crankshaft sprocket.
- Once everything is aligned, the large idler pulley can be securely fastened with the correct torque when the timing belt is properly tensioned.
- Properly tension the spring.
- Double-check all connections and verify the positions.
- Rotate the motor two revolutions in its direction of rotation, check the tensioner setting, and if necessary, adjust it.

Reassemble everything, start the engine, and use VCDS to check the synchronization angle in measurement block 4 of the engine control unit.
If the synchronization angle is outside the tolerance range, a fine adjustment must be made using the three screws on each camshaft gear.