This might not be related, but I have a refridgerant leak that I was helped with earlier. It will be too expensive to get fixed properly and of course it is out of warranty. Thanks Chrysler. I will remember that when it is time to buy another new car. I hate reading this forum and I just know the engine mounts are the next thing to clunk and I am waiting for my lights to start flickering. I just topped off the refridgerant. I live in MN so I figure I only use the air conditioner two months out of the year anyways.

Anyways... I have had an intermitant problem with a hissing sound from the passenger side dash. It used to sound like pressure was built up somewhere and then slowly released. It would be quiet and then repeat the pattern.

Now it spends more time hissing like a leaking air hose/tea kettle than on the quiet side of the pattern. It is does not seem to be related to engine speed, drive or park, RPM, night or day, cool or hot. It also does not seem related to fan speed for the vent system. Meaning that the noise does not increase or decrease when these variables happen, it is a constant level. I have a budget Pacifica so it has the cloth seats and basic air system. Not one of the fancy ones.

What I have found out that does affect it is the other vent selector switch - the one on the right side. This switch controls the vents and where the air comes out. The hissing noise only happens in the last 5 click positions going clockwise, or otherwords - the selections that seem to include the defrost on the windshield. If it is hissing, I can make it stop simply by going from defrost area to feet or any selection besides the last 5 clicks.

When the selector is on the other vents, no hissing noise. All vents seem to work ok and blow air evenly from all vents as selected. With the key on, but the car not started, I can hear the vent valves open and close as I move the selector ****.

I would assume if a valve was stuck and would not close or open as it should, then the hissing noise would increase or decrease with an increase or decrease in fan speed. It does not appear to do that, according to my ears. I would also assume that it would be a constant noise if a valve was operating incorrectly, not an intermitant noise. Of course now it makes more noise than being quiet, but it still cycles.

I am not a mechanic, but I have worked on cars. Older cars. I am nervous about puttering around behind the dash as I was warned that I might set off the air bag. Is that a concern I should have or are they safe and only an idiot would be able to set one off by accident?

Hopefully this is a part I could replace myself with some patience and help. I have more time than money.

Any ideas what it could be?

 

Nobody has a suggestion? Nuts. At this point I am willing to entertain unhelpful thoughts as well. Such as.... did you check to see if the neighbors cat is stuck inside your dash... my Pacifica does this too.... you poor bastard - that noise must be driving you NUTS!

 

My 04 did this on rare occasions. I think it has to do with the refrigerant passing through the lines. I thought I had read where people evacuated the system and maybe changed an expansion valve or something. Can you hear the noise after you shut the car off.. for 20 seconds or so? Like the pressure equalizing in the system. Ours did this.

Where is your leak.. in or outside the car.

I know this was discussed a lot in 2005 time frame but the forums I visit don;t seem to have the old threads anymore. I will keep hunting. Maybe do a search on hissing pacifica in google and see what you get.

 

its low freon due to your leak.

 

Now that Ctech says that, I think the posts that used to be out there said the cars came filled low from the factory. My car made this hiss (Darth Vader breathing!) since day one and we owned it 4 years. It always made icicles in the car. Is it possibly to be low enough to make noises in the lines yet still cool real well?

 

The noise is inside the car on the passenger side in the dash.

The ac lines in the engine compartment have an oil residue on them that has collected more dirt, lint, etc. I assume the oil is from the ac system and evidence that is where a leak is.

It made the hiss noise when the ac was blowing out cold air on passenger side but warm on the driver side. CTech told me to get the ac topped off. That worked for the driver side cold air, but I never paid attention to the hiss like I should have as I was rockin with the tunes in my cold car. Thanks CTech.

What annoys me is that I am not using the ac system now. It is cold as heck here in MN. I want to use the settings for defrost of the windshield. And because the ac is low on freon, now I have to listen to the hiss even if blowing hot air. I was just going to ignore it and roll down the window to get cool air or just top it off once a summer with refridgerant. But now it looks like you are forced to fix it, regardless if you want cold air, unless you want a constant hissing noise in the passenger compartment.

And I am not talking about the other hiss from the passenger side reminding me that it is still hissing and I thought you said you fixed it and this is irritating and I do not like your music so turn it off and now we listen to the hiss in silence.

HSSSSsssssssssssssssssssssssssssssssssssssssssssss sssssssssssssssssssssptht.






HSSSSsssssssssssssssssssssssssssssssssssssssssssss sssssssssssssssssssssptht.









HSSSSsssssssssssssssssssssssssssssssssssssssssssss sssssssssssssssssssssptht.






You should fix that.




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Yes dear.

 

HSSSSsssssssssssssssssssssssssssssssssssssssssssss sssssssssssssssssssssptht.


Called the shop. They will throw some parts at it. Might be just a gasket or we might have to replace an entire line. Will not know until we look at it.

Could get expensive.

Great.


HSSSSsssssssssssssssssssssssssssssssssssssssssssss sssssssssssssssssssssptht.

 

did you ever figure out what the problem was?

 

I have a 2007 Pacific and probably had every thing replaced on it. Transmission, front and back wheel bearing, rack and pinion, left and right road ends, and It goes on.
I also have a problem with the blower going off when I have the A/C on for at least couple of hours. The A/C is on but no air blowing.
The Lumbar just grinds when I try to use it.
The read a/c blower arm is loose inside I it sound like a manual pin ball machine.
I bought the Pacific back in 2009 with less than 25 thousand miles, at the 35 thousand the transmission went bad, as per the Dealership. Under warranty so they put a new one. Now at 65 thousand miles it's doing the same thing it was doing than.
I have a sound that the car makes when I am coming to a right turn, it sounds like something rubs with the brake on and turning. Took it to several dearler but they can't find anything.
The rack and pinion blew out the boot just a few months ago, cost me 1200 dollars to replace it. I had to pay for the front wheel bearing (both) and the rear left. But some still have some noise coming from the read, they say it's the right wheel bearing. That's another 300.00 dollars to repair.
We don't drive the car only to take trip up north to Niagara and upper NY. Most of the other time it's just sitting there.
I guess maybe I should have sold it after the transmission breaking at 35 thousand miles. All I have done is put money to a lemon.
Anyway I have had the hissing sound too, But I notice it when two of the four vents were closed. It's like a high pitch and hissing sound coming from the vents that remain open. The A/C is very cold when it doesn't stop blowing.
No more Chrysler for me. Oh that's my wife car. I have a 2013 Chevy Silverado.

 

$1200 for a rack and pinion replacement ??? You got taken for a ride, mine started leaking 4 years ago I bought one off of ebay for $125 that also came with new tie rods and my local mechanic installed it and gave the car a alignment for $250 still going strong after 4 years