January 4, 2001
By: Robert Leidy

There is an re-emerging trend, the Audi TT and a few other sports cars are starting to bring attention to, rather than hide the gas cap. If you're looking to draw a little more attention to your Z3 gas cap, then Hamann has what you're wanting.

This Aluminum performance gas tank cap kit from Hamann Motorsport contains everything you need to install it yourself, however one of the parts needs to be painted (body color). The installation sounds a little scary, but you can install it yourself in a little over an hour. The included instructions are in German the following is an English translation.

1. Take off right rear wheel and inner fender lining.
2. Take off tank flap with assembly. Take off tank cap.
3. Take off rubber lining around tank filler opening (will not be needed any more).
4. Install new HM tankcover insert and rotate into correct position (it will only fit in one position).
5. Drill insert at marked place with 2mm drill (picture).
6. Take off insert and enlarge drill hole to 3.5mm.
7. After painting of tankcover insert apply a thick coat of P1 adhesive to frontal area of tankfiller opening.
8. Attach HM tankcover insert using supplied 4x15 screws. Smooth out any excess adhesive.
9. After adhesive had hardened attach the HM-tankcover and gasket, align and mark drill hole point.
10. Take off HM tankcover and drill marked spot with 6mm drill.
11. Attach HM tankcover,gasket and some gasket material (?) with provided Senkimbus screws.
12. Reattach inner fender material and wheel.

There is some debate if you really have to take off the right rear wheel, one owner reported to me that he successfully installed the kit without removing the rear wheel. Not sure if he cut the rubber lining out or was able to just man-handle it out of there. If you're going to tackle a project like this use your own best judgement. The "scary" part of the installation (in my opinion) is step 7. Your gluing the painted fiberglass sleeve onto your gas tank filler opening, better get this done right the first time.

Everytime you start your Z3, the gas tank is "tested" by car. If you listen close you can hear an air pump pressurizing your gas tank. The system then monitors that pressure, if the pressure drops too quickly it triggers a check engine light because it thinks there is a leak in your gas tank. If you don't get an air-tight seal while cementing this part in place you're going to have check engine lights haunting you.

Below is a picture a reader sent in of the gas cap installed. Click on the picture for a larger image.