Located on the front of the block of my 740GLE there is some kind of plastic chamber that is mounted literally under the oil pan and frame and has a single nipple on the driver side and leads into the top of the intake manifold, also has a T in the middle that splits off a 1/4" O.D. white vacuum line that goes through the firewall and into the dash... What is this and what does it do for me? can i take this off and notice a change? (positive or negative)
my engine compartment is on 2 tables in my shop right now, someone please help[/align]

 

I am not that familiar with the older Volvo's. Is your 740GLE turboed? If so does your gauge cluster have a turbo (boost) gauge in it from the factory?

If so that vaccum line is running to that gauge and unless you plan to buy an aftermarket boost gauge I don't suggest taking it out.

 

I would think it would be the vacuum line that works the vent flaps for the a/c heat system. Alot of car use vacuum to change the flaps when you select vent/floor/ect...
Not sure but that is what it sounds like. Cutting it would make you air stuck on say defrost.....