S4 Avant Returns Home

About 48 months after picking up the S4 Avant from a fellow Audi enthusiast they contacted me offering to buy the Avant back if I ever was thinking of selling it.

Audi B5 S4 Avant
Audi B5 S4 Avant

As it turned out I had not been driving it very much.  I’d picked up a Mk7 GTI as a daily driver to replace my Miata.  The Mk7 GTI is very similar to the S4 with respect to exterior dimensions and comes in a few hundred pounds less weight.

VW Mk7 GTI and B5 S4 Avant
VW Mk7 GTI and B5 S4 Avant

The turbo engine and abundance of aftermarket parts options were another bonus, offering the opportunity to test with a different platform.

The opportunity to return the Avant to the previous owner made the decision to see it off easier to make.


First though there would be a final turbo swap, removing the Frankenturbo F21 v3’s for a pair of TiAL 605s’.

Turbo Swap Prep.
Turbo Swap Prep.
Engine Removal Prep.
Engine Removal Prep.

Knowing this would likely be the last time I was removing a 2.7T engine made it a bit easier to undertake what is probably the dozenth engine pull I’ve worked through.

Audi Engine Removed
Audi Engine Removed

Swapping turbos to the TiAL 605.

Passenger Side Turbo Installed
Passenger Side Turbo Installed
Driver Side Turbo Installed
Driver Side Turbo Installed

The engine only has about 50k on it, but having it out I took the opportunity to replace a few coolant hoses that have been in use for a number of years.

After run coolant pump hoses
After run coolant pump hoses

Back in it goes.

Engine Installed
Engine Installed

Nearly done…

2.7T Engine Installed
2.7T Engine Installed

With the Avant back with the prior owner and the GTI a family favorite daily driver a replacement project car was needed.  The Mk7 Golf R was what I settled on.  Similar to the B5 S4 but with enough differences to launch a new round of tests at MyGolfMk7.com

VW Mk7 Golf R
VW Mk7 Golf R – Covid Edition

Apikol Differential Bushing Blowout

A change in sound when accelerating led me on a search to find out what was going on.  Snooping around beneath the S4 revealed this:

Apikol B5 S4 Transmission Mount
Apikol B5 S4 Rear Differential Mount

Found it!  Fortunately Apikol sells just the bushings for the mount so I ordered a pair to replace the failed parts.

Apikol Differential Mount Bushing
Apikol Differential Mount Bushing

It turns out that there are two versions of this bushing so I needed to order both since I did not know at the time which version I have.  I’ve documented the part number in case this happens again.

Apikol Differential Mount Bushing
Apikol Differential Mount Bushing

Mamba Wastegate Bracket Update

Having had some challenges getting one of the Mamba wastegates to fit and ending up filing it down so it would work, I contacted Mamba to let them know about the fit problem.

They contacted me today to let me know that they had revised the bracket and wanted to know if I would like to have the updated version.

Since I already altered the part I declined to have a new bracket sent, but I’m glad to see they updated the part so it should have better success for others.

Mamba Revised B5 S4 Wastegate Bracket
Mamba Revised B5 S4 Wastegate Bracket
Mamba Revised B5 S4 Wastegate Bracket
Mamba Revised B5 S4 Wastegate Bracket

Audi B5 S4 Information and Testing