Inflating sound

i went out to the garage one night, about 4 hours after getting home, and the car was talking to someone.

 

Did you talk back?

 

don't speak the language.

 

Fairly certain the brake accumulator is not designed to "release pressure" (on purpose) under any circumstances. Check me in the service manuals to be sure. When you want the pressure released (as, for certain service procedures, you do), you can get there by first disabling the accumulator pump, then pumping the brake pedal a few dozen times. (At least, that's how it's done on Gen 1.)

Perhaps you heard a drop of moisture falling on a hot exhaust part, or the like....

-Chap

 

The first time I heard that I happened to be under it, had it jacked up. Just having a look 'round, if you must know... Anyway, it scared me silly for a moment, lol.

 

foreign language, yes? not japanese though, couldn't make it out.

 

Sounded like 3CPO talk, near as I could tell. Maybe: "should we flatten the human?"?

 

this isn't the droid you're looking for, move along.

 

The "hiss" sound is the fuel system depressurizing. Through the carbon canister of course. It will, after about 6 hours, repressurize it to check for leaks. Then it will "hiss" again.

I don't remember if Pearl S' manual is the same, but Pearl's manual (GII) had two facing pages discussing the sounds the car would make. Bottom line, "any sound the car makes is normal".

 

I haven't yet seen an explanation for the "Whirr-thump-thump-KuLUNK" that suddenly comes from under-hood roughly one minute after shutdown. Any ideas?

 

The noise I occasionally hear, hours after shut down, is the same, as that right after shutdown sound. Your description nails it, btw.

 

And it's "normal".

 

I heartily encourage curiosity about your car ... the more you understand, the better care you will be able to take of it, and the fewer unpleasant surprises you're in store for.

As for constructive ways to pursue that curiosity, there are several common avenues for you:

• Read the New Car Features Manual. Easy, indoors, comfy chair, any weather. You'll learn a lot.
• Lift the hood, try to localize the sound (either with unaided ears, or a mechanic's stethoscope, they're cheap). Still pretty easy. If you've had a skim over the NCFM, see if you can connect what you're hearing to something you've read about.
• Post recordings here.
• Use ideas from what you've read to see if you can make the sound happen (or change when it happens). For example, does it happen sooner if you have been pumping the brake pedal?
• Use some strategic fuse-pulling (guided by the manual, if you've looked), to see what makes the sound not happen.
• ...

All of these are usable approaches, likely not only to allay your curiosity but also to teach you stuff.

-Chap

 

Hah! Reading "New Car Features Manual", indoors, in comfy chair: that'd put me to sleep.

 

Have you tried it? More interesting than you might think. I'm on the edge of my seat for NCFM: 2016 to come out.

-Chap

 

I know that much, but I still don't know what the sound is. At least some of it seems to come from the vicinity of the EGR valve and cooler. Acquiring that New Car Features manual doesn't seem practical for now.