Introduction
For the benefit of anyone who may attempt to replace his/her own timing belt I am providing the following technical procedure as a reference point to be used along with the Bentley manual and proper knowledge and experience. I don't feel the need to provide any further disclaimer as anyone considering doing this understands what it means to wrench on a car, but since it seems like tradition here it is: I am not responsible for your work on your car. If you screw up you can do astoundingly expensive damage, hurt or kill yourself, or both.

The timing belt on the 2.7T should be replaced, depending on who you ask, between 60K miles and 105K miles. The range is absurd, but that debate can be handled elsewhere. I did mine at about 80K miles.

The procedure requires removing the front bumper and at least partially removing the radiator support (AKA "Lock Carrier" in the shop manual.) I will refer to it as Audi does for the remainder of this write-up.

There are two reasons why it is important to replace much more than just the timing belt. As with many repair procedures there is significant labor involved to get to the part in question. Other parts that could fail based on age should be replaced "while you are in there" to save on future labor. Also - and more importantly - things like the water pump and pulleys should be replaced because if they lock up they will kill a new timing belt and potentially kill your engine. This is not the time to cut corners. Replace all the parts listed below.

The procedure below is how I did the job on my 2001 allroad quattro. There are obviously variations and improvements possible and bumper/body differences between my allroad and the S4 or A6. I am not going to attempt to explain the factory way, alternate ways, or differences between different models. I am simply going to document how I did it.

Parts to Replace
As noted above, there are many "while you are in there" parts to replace as part of this procedure. It is widely known that ECS Tuning sells a kit that includes most of the major pieces the need to be replaced including:
- The timing belt
- Water pump with gasket
- Serpentine belt
- Idler roller
- Tensioner roller
- Thermostat with O-ring

In addition to the kit you will also need:
- G12 Coolant (1 gallon should do)
- Feedback on my write-up has consistently suggested that it may be a good idea to also replace the timing belt hydraulic tensioner though that isn't included in the procedure below

Tools and Supplies Required
I didn't record and exhaustive list of every tool required but here is a decent list to be sure you are prepared:

- A full set of basic metric hand tools including sockets, wrenches, extensions, etc.
- Torx drivers (T-20, T-25, T-30, T-45)
- Cam Lock Bar (a special Audi tool that I borrowed as seen in pictures below)
- Crank lock pin (I made do without)
- Fan removal "chopsticks" (I made do without)
- Distilled water is best (I used soft tap water)
- RTV gasket goop
- Some solvent of some kind
- Toothbrush or similar
- Rags, paper towels, etc.
- Bentley Manual

Procedure
Again please note that this was my procedure, not the only possible way.

Preparation

Jack front of car and support on jack stands. Remove front wheels. Remove belly pan (detail here.) Open hood. Remove center "V6" logo plastic engine cover.



A - Remove Bumper

A1. Partially remove fender liner in each wheel well by removing several T-25 torx fasteners and pulling the front part of the liner back so you can work behind it.



I temporarily zip tied it out of my way so I could work behind it in peace. Don't leave it like this too long or it may crease.



A2. Now look behind the liner toward the front bumper. What you are after are the three 10mm nuts on each side aligned in a vertical column. Remove them with an extension on your ratchet.



A3. Remove the intercooler grilles (they surround the fog lights). Just pull straight out with your hands on the strong part of the grille. It will pop right out.

A4. Remove 2x 8mm allen head bolts oriented vertically inside fog light enclosure.





A5. Remove 2x per side T-20 torx attaching bumper to the 'bumper guide' where you peeled back the fender liner.

A6. Unplug fog lights

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