AC Hissing/Spitting Sound Under Dash

[Lee29720]

I have an 06 EX EB 4.0 2wd with 27k miles. I took it in for some other warranty work and I reported a hissing/spitting sound when the AC is turned on. The noise sounds like a pressure release, but is repetitive. It kind of sounds like a pressure cooker releasing steam. It comes from the PS under the glove box.

The dealer, of course, could not duplicate or repeat the noise. I can't pinpoint the location myself.

Any thoughts? It is only when the AC is on and more pronounced on #1 fan setting.

 

[96eb96]

I have an 06 EX EB 4.0 2wd with 27k miles. I took it in for some other warranty work and I reported a hissing/spitting sound when the AC is turned on. The noise sounds like a pressure release, but is repetitive. It kind of sounds like a pressure cooker releasing steam. It comes from the PS under the glove box.

The dealer, of course, could not duplicate or repeat the noise. I can't pinpoint the location myself.

Any thoughts? It is only when the AC is on and more pronounced on #1 fan setting.

Check to see that all the settings on your A/C works. Do you have floor and vent functions that switch quickly?

Not sure about the specifics of a 2006, but I would ask the dealer to inspect the vacuum lines that control the A/C doors. The A/C unit opens and closes vac to lines that have special vac control motors. If a vac line is slightly cracked...you can imagine the sound.

 

[TheJackal]

Usually under-dash hissing is attributed to a vacuum leak.

Tell the dealer you think it's a vacuum issue. I made the mistake of bringing a car to the Ford dealer with a small vacuum leak and told them the A/C wasn't working right, thinking they'd fix it, but when I returned I found they didn't have a clue...