Pressure Release Sound Upon Shutoff

Gageraid · **Posted:** Tue Aug 13, 2013 11:38 am

Does every KK make this sound when they shut it off, or is it just mine? Has always happened. Every once in a while it's not as obvious, but just sounds like some sort of pressure release as soon as you turn her off.

Just want to make sure this is normal, or if I should look deeper into this. :juggle:

ajohns1288 · **Posted:** Tue Aug 13, 2013 6:10 pm

Sounds kind of like a quick "shhhh" coming from somewhere up front? Mine does that too sometimes. I think it might be the check valve on the brake booster sealing up. I'm more worried about the clunk right before the first 1-2 upshift on a cold star, but the radio is still loud enough to cover it up.

tommudd · **Posted:** Tue Aug 13, 2013 6:17 pm

Have you checked the radiator cap ?

huntb · **Posted:** Wed Aug 14, 2013 8:43 am

Mine definitely makes a noise like that when I shut it off when the AC has been running

DREDnot · **Posted:** Wed Aug 14, 2013 11:30 am

mine has always had a post shutdown movement of the HVAC doors. I've surmised they reset to some neutral position so that they can give you that uncomfortable pause on startup.

Gageraid · **Posted:** Wed Aug 14, 2013 11:36 am

huntb wrote:

Mine definitely makes a noise like that when I shut it off when the AC has been running

I rarely use the A/C. I think I used it 4 times this Summer.

Gageraid · **Posted:** Wed Aug 14, 2013 11:37 am

tommudd wrote:

Have you checked the radiator cap ?

Checked it less than a month ago, but will check it again today.

Gageraid · **Posted:** Wed Aug 14, 2013 11:37 am

Almost sounds like a blow off valve on a turbo engine.

Bmxer524 · **Posted:** Wed Aug 14, 2013 1:31 pm

Does it seem to happen all at once or does it go on for a few seconds? It might be the cold air intake if it's a few second hissing sound.

Gageraid · **Posted:** Wed Aug 14, 2013 1:33 pm

It's like a one second sound if that.

Gageraid · **Posted:** Wed Aug 14, 2013 11:02 pm

tommudd wrote:

Have you checked the radiator cap ?

Took off the radiator cap and put it back on. Nothing abnormal about it that I could tell. I drove her a few times today, but forgot to pay attention to the sound each time I shut it off. I'll report back this weekend.

Gageraid · **Posted:** Sat Aug 17, 2013 4:22 pm

Drove a lot this weekend and it didn't make the noise at all HOWEVER I didn't do any short trips, which is when I think it happens. I'll keep my ears open this week since my daily driving is always full of short trips.

Gageraid · **Posted:** Tue Aug 20, 2013 4:08 pm

Back to my usual routine it's always making the noise if I drive say less than a 10 mile trip.

DREDnot · **Posted:** Wed Aug 21, 2013 3:28 pm

Have you stuck your head under the hood while someone else shuts the engine off to get a better location of the noise?

Gageraid · **Posted:** Wed Aug 21, 2013 5:18 pm

DREDnot wrote:

Have you stuck your head under the hood while someone else shuts the engine off to get a better location of the noise?

No, but that's a good idea. Pretty sure it comes from the intake area or at least from the passenger side. I'm guessing it just has something to do with the engine not being fully warmed up yet.

Pressure Release Sound Upon Shutoff

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