Update 4 is a large one, with lots of small stuff happening since we  gave our last update. Since it’s been a while, we figured a quick recap would be the best way to start:  When we last left off, we had pulled the old and slow 2.8/tiptronic from our wagon and were in the process of cleaning the bay. We had already dismantled and scrapped the old motor as well as pulled the S4 donor motor.

We finished prepping the shell, and we’ve now turned our attention to cleaning, repairing and replacing all the worn-out components on our S4 drive train. We started by cleaning the entire motor and pulling off the various brackets and accessories for paint and detailing. To clean all the old oil and grime of the motor we employed the force of a pressure washer aided by a ton of engine degreaser. We were careful to plug any holes leading to the internals, and we bagged all exposed connectors and wire harnesses. We found zip ties and plastic bags to be the best method of sealing all the delicate parts of the engine loom. With the prep work finished, we began to spray down the engine with a liberal amount of degreaser. After letting the chemicals sit for a minute, we blew off most of the grime with the pressure washer. The process was repeated until most of the dirt was gone. Then we went in with an assortment of small wire brushes to take the final bit of stubborn dirt out.

While the wash took most of the dirt out, we still had tons of cleaning prep to do. We pulled off the more delicate systems like the fuel rail and its associated lines – these we cleaned by hand with a tooth brush. While time consuming and tedious work, the results speak for themselves. We also stripped down the brackets and other mounts to prep for paint. Working with sand paper and a wire wheel, we took the old paint and grime off the motor mounts, transmission mounts, heat shields, and the intake manifold. Once completely clean and free of oil, we sprayed these components with black high-temp chassis paint. We also took the time to do the same for the coolant pipes and timing belt covers. Did we need to?   …maybe not, but it did make the entire engine a lot cleaner and will help prevent rust in the future.

With the bulk of the engine taken apart and all its pieces either painted or clean, we began the reassembly process. A timing belt service was first up: we installed new rollers, water pump, and tbelt at the same time to replace the old and worn out components. We opted to use a Gates belt, which we hope will withstand the higher power levels our new turbos will put out. The timing belt job was an easy one – we followed along with a DIY from a fellow forum member. We spent most of our time double checking our work and making sure the bolts were tightened to the correct spec. The process was made easier by having the correct tools, and we highly recommend using whatever tools your DIY guides or mechanics recommend. The cam locking bar and crank pin are mandatory for a timing belt service.

When locking everything in place we used a paint pen to mark the old belt, cam gears, and crank pulley.  We transferred those marks onto the new belt by counting teeth to ensure accuracy.  This allowed us to make sure the timing was not thrown while changing the belt.  Bad timing will cause the car to run horribly and may bend the valves, ruining the engine.   We followed the procedure outlined by Audi for applying the correct tension using the tbelt tensioner. The other major catch about doing a timing belt job is to make sure your rollers are installed the correct way. Be sure to use the old hardware as a guide and make a note of how the old parts were installed.

Once the timing service was completed, we put the rest of the motor back together. We started with the power steering pump and moved on to the covers and accessory belt tensioner.   We ordered a new one, since the old bearings starting to go.  After that we turned our attention to the top of the motor, reinstalling our freshly painted intake manifold and new gaskets. We then installed new 550cc injectors and the adapters provided by 034 Motorsports. We also test fit our freshly cleaned fuel rail.

With all this done, we’re taking a well deserved break for now – but we can’t stay away for too long!  We’ll be back before you know it with more updates, starting with the valve covers and various seals.  As our Audi Avant Restoration project inches closer to completion, it’s getting harder to contain our excitement. Stay tuned for the latest on our wagon project and thanks for reading!  #Avant

-CA Staff