hisss noise sounds like air leak (think i found the source)

lilnicko11 · Post by **lilnicko11** » Mon Jan 25, 2010 10:07 am

in my SRT4 only in cold weather when I start my car there is a very small hiss/ leak of air that I can hear coming from behind the controls. It never happened in the summer time. I believe it may be coming from the inside/outside air knob. I had a new stereo head unit put in in July and the tech at best buy broke a clip off the back on the control panel. He was able to glue it back together and I was satisfied but I still to this day regret not filing a complaint. But anyways, does anyone know what could this be or how much an entire new control thing would be? Sorry for the noobish terms. The sound/leak does go away after a couple minutes. Maybe I could take a vid but it may be too low of a noise to hear. Any thoughts?

Caraudioholic24 · Post by **Caraudioholic24** » Mon Jan 25, 2010 12:25 pm

Sounds like a small vacuum leak coming from the heater/ac control unit. Did he rip any air hoses when installing the raio. If not then the plastic part that he broke may still be leaking so u may have to get another unit.

I have one if you decide you wanna get one. Let me know.

lilnicko11 · Post by **lilnicko11** » Mon Jan 25, 2010 1:01 pm

how much do the units usually cost??

OB · Post by OB » Mon Jan 25, 2010 9:41 pm

Probably a couple hundred bucks from the dealer. And I don't think NAPA is gonna have one

Sounds like a run of the mill vac leak to me. Get in there and fix it.

Post by **occasional demons** » Mon Jan 25, 2010 10:32 pm

OPERATION
Normally, vacuum is supplied to the actuator by
placing the recirculation control knob in the RECIRC
position. The mode and the recirculation controls are
mechanically interlocked so the recirculation control
cannot be placed in the RECIRC position if the mode
control is at/or between the mix and defrost positions.
Vacuum is supplied to the actuator only when
recirculation control is at the RECIRC position.

Prolly at the HVAC controls, or where the vacuum harness hooks up.

4885336AA Hvac Controls neon, w/ac 2000 - 2005 $88.50

I figured a lot more, also. Sometimes you can pick them up on ebay, or Caraudioholic24.

lilnicko11 · Post by **lilnicko11** » Tue Jan 26, 2010 12:59 am

thanks guys

Caraudioholic24 · Post by **Caraudioholic24** » Tue Jan 26, 2010 1:25 am

if you decide it is the unit let me know and we can talk on a price!!

lilnicko11 · Post by **lilnicko11** » Tue Jan 26, 2010 10:39 am

88.50 for a whole new piece. not bad. i'll look into it and pull everything off once warmer weather gets here. thanks guys. ill keep everyone in mind too depending on what i find.

lilnicko11 · Post by **lilnicko11** » Sun Jan 31, 2010 4:13 pm

Can this be linked to a coolant smell and/or leak at all??

Caraudioholic24 · Post by **Caraudioholic24** » Sun Jan 31, 2010 4:16 pm

Hmm if its just the vacuum lines I would say no. Is it in the car or outside.

lilnicko11 · Post by **lilnicko11** » Sun Jan 31, 2010 4:18 pm

the smell is inside. its not overwhelming but i can notice it. as for the hiss noise, it stays for a few minutes and then goes away.

Caraudioholic24 · Post by **Caraudioholic24** » Sun Jan 31, 2010 4:23 pm

Thats weird any wetness on the floor near the heater core. I cant see the smell coming throught the vacuum lines. Weird

lilnicko11 · Post by **lilnicko11** » Sun Jan 31, 2010 4:35 pm

negative. no wetness. i have no idea.

Caraudioholic24 · Post by **Caraudioholic24** » Sun Jan 31, 2010 4:39 pm

I can tell you the hiss is from the vacuum lines and you will need to get a new hvac controller. But I think you already knew that. As for the smell I would stick your head in the area of the heater core and sniff around. Do u get any type of moisture in your windshield?? Thats the first sign that its on its way out.

lilnicko11 · Post by **lilnicko11** » Sun Jan 31, 2010 4:48 pm

Yeah I do get moisture on the windshield. This could be why my defrost sucks so bad. So what do u think. I need a new heater core/hvac controller?

Caraudioholic24 · Post by **Caraudioholic24** » Sun Jan 31, 2010 4:58 pm

Yea man the moisture on the windshield is the first sign of the heater core on its way out. Thats what happened on my last corolla. I didnt think anything of it till the entire pass side floor was soaked in radiator fluid.

Sorry to be the bearer of bad news.

lilnicko11 · Post by **lilnicko11** » Sun Jan 31, 2010 5:12 pm

do i even wanna ask how much a new core would be? Im suprised tho, cause the SRT4 is an 04 with only like 53,000 miles on it and very rare winter use with all past drivers.

Pablodragon · Post by **Pablodragon** » Sun Jan 31, 2010 6:55 pm

the heater core itself is not too expensive...the problem is getting to it to replace it.
Had a mechanic friend of mine do mine. Took him a day and a half to get the whole dash part to get to it, then a day and a half to put it all back together. (Course he wasn't a Neon guy)

Funny thing also about the hiss noise... after he did that core for me, was getting the hiss also, and what I found...had to just remove the HVAC controls enought to get to the back...he put the vacuum connection on the back of the inside/outside control on upside down...just flipped it over and pushed back on, no more hiss

lilnicko11 · Post by **lilnicko11** » Sun Jan 31, 2010 7:10 pm

maybe its that. possibly the inside/outside is on wrong.....ill check it out on a warm day.

Post by **occasional demons** » Sun Jan 31, 2010 10:13 pm

Not to make things more difficult, but, if the recirculation control is not moving the recirc. door properly, you will get fog build up on the interior, because it is not bringing in outside air. Switch the outside/inside control back and forth. You should hear the door shifting. The fan speed usually sounds different also. If there is no change, it could be part of the foggy window problem.

Edit: Pablo may just be on to it tho.

lilnicko11 · Post by **lilnicko11** » Mon Feb 01, 2010 10:18 am

so could the inside/outside air be on backwards behind it when i had a clip fixed back there? if not ill just have to replace the hvac i guess.

Caraudioholic24 · Post by **Caraudioholic24** » Mon Feb 01, 2010 10:24 am

Could be but like you said it was broken so if its leaking there is no pressure for the vacuum to work so yea your gonna wanna get a new one. I would get in there and take a peak and see what you come up with.

lilnicko11 · Post by **lilnicko11** » Mon Feb 01, 2010 12:54 pm

SO I TOOK IT APART TODAY. I'm pretty sure I've narrowed it down to the inside/outside air clip. The "hisss" noise is coming from one of the small holes. I also think that it is stuck on the inside air option thus causing my defrost to suck really bad unless I put down a window slightly. The clip was reglued on after the Best Buy guy broke it when putting in my cd player but with time and weather the clip has loosened and pretty much fallen off. Looks like I'm gonna have to get a whole new HVAC and hopefully that will solve all the problems. All the 00-05 are the same right? What do they run brand new? I believe someone on here said about $90ish. Caraudioholic you have one used for sale also right?

Caraudioholic24 · Post by **Caraudioholic24** » Mon Feb 01, 2010 2:06 pm

Yes I do. Pm me if you are interested.

lilnicko11 · Post by **lilnicko11** » Mon Feb 01, 2010 6:44 pm

Pablodragon · Post by **Pablodragon** » Tue Feb 02, 2010 10:15 am

Did you try flipping that connection over and putting it back on?... didn't seem to read that... or is that connection really broken...

reason I ask is, 1)..took me looking at it about 2 times to figure out it was upside down..and
2)..there should be no "small hole" where vacuum/air could be 'coming out' of

sorry if you already went thru this, or I didn't read the posts right...

EDIT:...ah, poop...never mind, think he did say that it fell off...me bad

lilnicko11 · Post by **lilnicko11** » Tue Feb 02, 2010 10:40 am

here are some pics. showing the front (which is fine) the other pictures u can see where the clip is no longer attached to the back of the inside/outside air option controller. Also the spring and other piece has fallen out. Also notice the two small pin holes for the differing air options.

lilnicko11 · Post by **lilnicko11** » Tue Feb 02, 2010 2:46 pm

My friend at dodge says he can get a new HVAC for $62. im gonna call the area junk yards as well and negotiate with peeps on here before making a decision. Luckily I dont have to rush since I'm driving the ACR anyways.

tbagg1ns · Post by **tbagg1ns** » Fri Jun 12, 2020 11:46 pm

Sorry to dig up a dead thread, but I just had my heater core replaced in my srt4 and the HVAC controls hissed when I got it back.

Well, turned out the vacuum lines on the freah/recirc knob was on backwards like as was described above. They had the empty port jammed onto that flat black piece.....I mean I can see how that's an easy thing to do, but this is the only thread I could find that had the info. So thank you.

Post by **occasional demons** » Sat Jun 13, 2020 10:23 pm

LOL, thank you for taking the effort to create an account and post here! Welcome to the forum, even if it has gotten pretty slow as the neon scene is not what it used to be.

About the only new people registering these days are spammers...

2GN.ORG

hisss noise sounds like air leak (think i found the source)

hisss noise sounds like air leak (think i found the source)

Re: hisss noise sounds like air leak (think i found the source)

Re: hisss noise sounds like air leak (think i found the source)