budge96

I believe number three is a vacuum accumulator it,resides either next to or behind the air filter box...Bert

TheTorch

yup, #3 is a vacuum reservoir.

TravisRT1985

When I Google carrera vacuum reservoir I’m only seeing them for years 1995 and up. Is that item necessary on a 87-89? Thanks

TheTorch

I am not sure but I think the vacuum res started with the 964 / 993 intakes.
The PET doesn't show a reservoir for 87-89. http://www.autoatlanta.com/porsche-p..._911_parts.php
The picture in the thread above shows what appears to be a 964 intake. http://www.autoatlanta.com/porsche-p..._911_parts.php

Sometimes of course Porsche blended parts during transition years so that can make things confusing.