Porsche 996 Coolant Cap Replacement - Versions of the 911 Coolant Reservoir

The coolant reservoir cap for the Porsche 911 996 variant has been revised 4 times by Porsche with different amendments for each version. The coolant cap part number is 996.106.447.00

As you can see my car had the original 996.106.447.00 version so I upgraded to the 04 version as a preventative step to avoid any problems.

Porsche 996 Coolant Cap 00 version

Porsche 996 Coolant Cap 00 version

What are the differences between the versions of the Porsche 996 Coolant reservoir cap?

The most obvious one is that the centre section with filter/grille has been made smaller and surrounded by an extra ring of plastic. It's not clear what benefit this brings but there must have been a reason to amend the cap to improve sealing or reduce leakage.

Current coolant cap part number 996.106.447.04

Porsche 996 Coolant Cap 04 version

Porsche 996 Coolant Cap 04 version