Vacuum leak behind HVAC? Video added

Passt · Post by **Passt** » Thu Apr 05, 2012 2:45 pm

I've had a vacuum leak for a while (car idles @ -15vac), and I've heard what I thought was some air behind the HVAC system in my SRT. Today I popped the bezel off to take a closer look, and the air noise is much louder. I don't see anything immediately noticeable or out of place, but at the same time I'm not sure what everything is supposed to look like back there. Here are a couple pics.

http://www.youtube.com/watch?v=tePk_1no ... e=youtu.be

In the second picture, there is a 3rd clear rubber / plastic nipple that looks like something should be plugged in there, can anyone confirm this? Or if anyone has any experience in general behind the hvac controls and knows if there's some sort of vac line running around back there, the help would be much appreciated.

Passt · Post by **Passt** » Thu Apr 05, 2012 9:15 pm

Any ideas? Someone on Srtforums stated there's a vacuum line that is supposed to connect to the control which allows me to choose between outside air and circulated air. Can anyone confirm?

thttxboy · Post by **thttxboy** » Thu Apr 05, 2012 9:53 pm

Hey nate, heres a link to help you out wat it looks like behind the dash

http://www.hpaircraft.com/neon/heater_core.htm

Jenni · Post by **Jenni** » Fri Apr 06, 2012 2:15 pm

The third nipple should be empty. Looks all good in your pictures.
Follow the lines if they are broken anywhere.
Could it be the boost gauge vac line?

Passt · Post by **Passt** » Fri Apr 06, 2012 3:35 pm

I don't think it's the boost gauge line, that's all the way to the left in the A pillar now. Thanks for the reply Lego

superdan · Post by **superdan** » Fri Apr 06, 2012 7:37 pm

Yeah I would check to see if those lines are cracked anywhere. You can take your dash pad off and see where they go. Its easier if you take the vent tunnel out of the dash as it just pulls out with a little finesse. Plus you will be able to get your hand back there a lot easier to feel for any leaking air.

Hope that helps.

Post by **occasional demons** » Fri Apr 06, 2012 9:48 pm

Not 100% sure on how the vacuum switch works, but have you tried to see if that open nipple is sucking air? If the switch is bad, it may leak through that nipple.

I'm only guessing it is to vent atmospheric pressure back in once the vacuum is switched off. Just a shot in the dark...

Passt · Post by **Passt** » Fri Apr 06, 2012 9:48 pm

Found the problem. The leak is coming from that little black piece that the red and black hoses connect to. I did check to see if that third opening was the issue, but alas, it was not. I ended up capping the line at the brake booster. I can no longer switch between circulated air and outside air, but who cares. Not me

Post by **occasional demons** » Fri Apr 06, 2012 9:49 pm

Ha! I was close!

chip0wa · Post by **chip0wa** » Tue Jan 13, 2015 3:54 pm

Would this be the same on a regular neon? Just curious because with the old car after sitting for a couple months starting it up there was definitely an air type noise coming from the vents. It would go away when accelerating, then once you shifted and were crusing at speed it would come right back.

Post by **occasional demons** » Tue Jan 13, 2015 5:40 pm

There is no difference, as far as the HVAC controls. The benefit is the vacuum leak will make noise, so tracing the lines should lead you to it eventually.