Vacuum Line Help
Thread Starter
Pro
Joined: Mar 2013
Posts: 628
Likes: 13
From: Indiana
Vacuum Line Help
While working under the hood I noticed a vacuum line that fastens to the rubber accordion that goes to the throttle body and passes down behind the idler pulley and disappears. Apparently it popped off of wherever it was fastened and ended getting ground in half by the idler pulley. It enters on top just after the MAF. Does anyone know where it goes to and what it is used for? I used a short piece of hard plastic tube to stick it together but would like to replace it with new if possible. This is a 96' LT-1 engine. Where is the other end? Here is a pic.
Last edited by Klyde; May 9, 2013 at 12:01 AM.
Safety Car
Joined: Jan 2004
Posts: 3,556
Likes: 13
Burning Brakes
Joined: Jan 2012
Posts: 1,191
Likes: 153
From: Gilbert AZ
2018 C1 of Year Finalis4
That line feeds the fresh air into the Opti. There are two nipples on the Opti. The second one feeds back through a small filter under your fuel rail cover (drive side) and feeds back into the manifold. If yours is damaged, your going to want to fix it. There should be lots of pictures and info if you search for vented Opti on the C4 forum. If you can't find anything, post back and I'll try to get some info up for you after work today.
The last link from vetteoz has some pic's of a modified Opti and shows the vacuum hoses.
The last link from vetteoz has some pic's of a modified Opti and shows the vacuum hoses.
Last edited by ColaBear; May 9, 2013 at 09:11 AM.
Thread Starter
Pro
Joined: Mar 2013
Posts: 628
Likes: 13
From: Indiana
Can you get to the hose connection on the opti from the bottom of the car? I can't even see the opti from top let alone replace the hose. I need to figure out what size vacuum hose I need and then get the car back up on jack stands again.
Burning Brakes
Joined: Jan 2012
Posts: 1,191
Likes: 153
From: Gilbert AZ
2018 C1 of Year Finalis4
Not really.
It will be helpful to pull the belt off, remove the intake housing at the throttle body, un-bolt the alternator, pull your driver side inner wheel well lining off (the back half from the shock to the battery area).
The original vent hose routes down behind the alternator and the idler pulley by the driver side of the water pump. I got longer vacuum hose and re-routed my lines over to the bottom and around the AC and alternator so I would not have to deal with it during a water pump change. The first time, I pinched the hose under the water pump and it leaked like crazy since the water pump could not seal against the block. It also ruined the vacuum hose. You can’t see in there and the vent hose is just in the way.
I don’t remember the size hose a used but it takes around 4 to 5 feet to re-route.
Hope this helps.
It will be helpful to pull the belt off, remove the intake housing at the throttle body, un-bolt the alternator, pull your driver side inner wheel well lining off (the back half from the shock to the battery area).
The original vent hose routes down behind the alternator and the idler pulley by the driver side of the water pump. I got longer vacuum hose and re-routed my lines over to the bottom and around the AC and alternator so I would not have to deal with it during a water pump change. The first time, I pinched the hose under the water pump and it leaked like crazy since the water pump could not seal against the block. It also ruined the vacuum hose. You can’t see in there and the vent hose is just in the way.
I don’t remember the size hose a used but it takes around 4 to 5 feet to re-route.
Hope this helps.
Thread Starter
Pro
Joined: Mar 2013
Posts: 628
Likes: 13
From: Indiana
Thanks ColaBear and Vetteoz for the info. The pictures help a lot. There is a picture that shows where the small metal clip is supposed to fasten. This is what popped off and allowed the hose to grind against the idler pulley. It is crazy how difficult replacing 18 inches of hose is going to be. I hoped I could get to it from underneath and use the old hose to pull the new one into place. At least I know what it is for and the patch I made should be good for a little bit while I work this out. The problem is I have no ideal how long it has been leaking and what damage there is to the opti. Once again thanks for the response and info. If I come up with an easy fix I will post it. I have my doubts though.
