[Reddog99]

And not when the engine is running.
I was sitting near the car tonight while looking for meteors in the sky and heard some noises from the Fiesta every couple of minutes. At first I thought it was a critter prowling the engine compartment, but it was something else, some mechanical noise coming from the left front.

It's been at least five hours since the car was running, so it was only lukewarm. Maybe some emission parts? Anyone care to guess?

 

[Jazzdog]

Can you provide a better description of the the noise? High or low frequency, tap, click, pop, sizzle.......

 

[MGREEN11]

Was the car even running?

 

[Reddog99]

The noises are hard to describe. It wasn't liquid gurgling. It wasn't high or low frequency, tap, click, pop, sizzle. It was mechanical, medium frequency, as if a series of plastic valves were operating. The noise only lasted about one second, then stopped for several minutes.

It scared the bejesus out of me the first time. I live in the country and it was pitch dark so I couldn't tell what made the noise, only that it was at the car. We've had the occasional mountain lion around here, so I've been wary...

 

[Jazzdog]

Did you have aux power on - listening to the radio? If aux power was on did you have climate control off? Thinking it was climate control internal door opening/closing but not my area. Any insight LMTech?

 

[Casca]

The noises are hard to describe. It wasn't liquid gurgling. It wasn't high or low frequency, tap, click, pop, sizzle. It was mechanical, medium frequency, as if a series of plastic valves were operating. The noise only lasted about one second, then stopped for several minutes.

It scared the bejesus out of me the first time. I live in the country and it was pitch dark so I couldn't tell what made the noise, only that it was at the car. We've had the occasional mountain lion around here, so I've been wary...

On my bimmer, it's the air recirculation valves/bladder opening/closing or filling up/letting out air to accomplish whatever the heck it is doing. Supposedly normal. I think it opens and closes in relation to air temps inside the car and outside the car after you park and no longer have a/c running, so it could be a while before it does it's thing. Is the noise you hearing coming from a/c vents or near?

I haven't looked up what it really is, but on my car it sounds like a bladder that expands when I start the car and use a/c (barely hear it on start up and that was after I hunted for the sound), then when I shut the car down, as the temps change and my car cabin starts losing the cold from the a/c, the bladder starts shrinking. Start hearin the noise maybe 10 minutes after I shut down and no doubt it could still be shrinking hours later.

 

[iamz]

Sounds like a mountain lion....Yep.....Pretty sure you were just hearing a mountain lion.

 

[Reddog99]

I wasn't in the car, hadn't been in the car for five hours.

After the mountain lion thoughts, a big racoon came to mind, then I downgraded that to a night-time squirrel after the third time I heard it. Eventually, I popped the hood to look under, but the noise didn't occur while I looked.

 

[LMTech]

It may have been the emission control vent valve opening to compensate the fuel tank pressure in the tank since the outisde temp was dropping ( I assume that the air temp was declining ). This is only a guess since I can't hear the noise or don't know the exact location that it was coming from.
On the other hand it could have been real tiny aliens that were coming from the meteors landing on your car.

 

[Coop]

Sounds to me that it is the exhaust system cooling down and shrinking from being expanded while running with hot exhaust (causing that noise). Many vehicles do that!

 

[LMTech]

Not after sitting for 5 Hours.

 

[golf strom]

It may have been the emission control vent valve opening to compensate the fuel tank pressure in the tank since the outisde temp was dropping ( I assume that the air temp was declining ). This is only a guess since I can't hear the noise or don't know the exact location that it was coming from.
.

This is likely it...most late model cars and especially European ones sold in the US have this noise......I agree it is a evap solenoid opening and closing