The D3_1_3.exe file you have requested: Official Patches / DOOM 3 v1.3 Win32 Patch - 32.41mb is not available. Perhaps try browsing all files for the game Doom III and upload any files you want to share or are missing. This is the only information we could locate:
The 1.3 patch for DOOM 3 and updated SDK are now available on the id FTPserver , on Doom3.com  and on the torrent tracker .Please refer to the documentation after installation for a completelist of changes since version 1.0. This patch will update DOOM 3 to version 1.3.