what does this hose do? - 306 XSi

Hi all
I had a look in the postings in this ng recently as my 306 xsi has
been behaving a little oddly - a while ago I had the idle stepper
motor replace and I was having similar symptoms to that time.

I started looking for air leak problems and soon discovered a 'nick'
in a hose. When I started to take the hose off to better examine it it
fell apart in my hands! I like the sort of fault diagnosis that works
like this ...

I've replaced the hose and my engine is now idling better, without
hunting, and behaves better when I take my foot off the accelerator.
Thing is, I would like to know what this hose actually does, & what
it's called.

It's a hose around 30cm long which connects from just near where you
top up the oil, to near the throttle, where the stepper motor is
found. The stepper motor end is narrower than the other end, and
there's no reference to it in my Haynes manual FWIW. Can anyone
advise?

Thanks a lot
Jon N

 

sounds like you have a vacuum hose there, which will indeed cause poor
running if its leaking, any of the many vacuum hoses coming from your
manifold will do the same.
not every part under your bonnet (hood) has a specific name, many of the
hoses whether vacuum or coolant hoses are just "hoses" with maybe a name to
descibe where they are located on your engine,
we buy rolls of vacuum hose and just cut off whatever length we need to
repair an individual job.
steve uk.