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  • 1996 - 2004 SN95 Mustang -General/Talk-
  • SN95 4.6L Mustang Tech

Do I worry too much?

  • Thread starter Thread starter Miller220
  • Start date Start date Mar 15, 2010

Miller220

Member
Sep 12, 2009
36
0
6
Mar 15, 2010
#1
  • Mar 15, 2010
  • #1
OK.....I'll be quick because I need to sleep BUT I wanna get this stuff outta my brain while its still fresh.

1) When I turn off my car it makes a hissing noise from around/under the intake manifold like there is air coming from somewhere...then it stops and thats it. (I took it to a shop and they said that its not cracked? He said that they sprayed around the intake manifold with something and if it was cracked, it would have raised the RPM's some, but nothing happened...so I dont know.)

2) When the car is at idle, I can gently push the gas pedal till the car hits 1000 rpm, and if I let go..it will sometimes drop as low as 500-450.........sometimes about 425..then bounce back up to 600...is THAT normal?

and LASTLY 3) I had found this one by accident...I put my windows down while I was parked..and it'll drop down to around 500 rpm's till I lift off the window buttons..I figure this is semi normal because its sucking power. Is all this normal and I just happen to be worried too much, or is there something legitimately wrong with my car?
 

D-BOI

Member
Mar 26, 2009
596
1
17
Metro Detro
Mar 15, 2010
#2
  • Mar 15, 2010
  • #2
you need to check everything all those hoses leading to the intake maybe there is a vacuum leak
but the 3rd one is very normal it does it on mine and all other cars
 
P

peepeeskillz

New Member
Mar 23, 2009
171
0
0
texas
Mar 15, 2010
#3
  • Mar 15, 2010
  • #3
mine makes that hissing noise sometimes after i turn the car off if i have been using the a/c, but i never bothered to check where it was coming from, it was doing it since day 1.
 

trombonedemon

Well-Known Member
Jun 25, 2009
1,962
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U.S.A, U.S.A., U.S.A.!
Mar 15, 2010
#4
  • Mar 15, 2010
  • #4
My car does that as well but, I think it is the gases still escaping from the valve covers through my catch cans out the CAI. Your first seems like the computer trying fine a good idle rpm, is it this first crank in the morning, at the start of a drive cycle?
 
K

Kilgore Trout

Fried or Broiled ?
10 Year Member
Mar 30, 2005
4,749
95
134
Mar 15, 2010
#5
  • Mar 15, 2010
  • #5
All that stuff is normal OP.
 

joshwfl

Member
Jan 31, 2010
111
0
16
Mar 15, 2010
#6
  • Mar 15, 2010
  • #6
Yup, mine does the hiss too.
 

MaxedGT

Member
Mar 31, 2005
304
0
17
Surrey BC Canada
Mar 15, 2010
#7
  • Mar 15, 2010
  • #7
The hiss is the pressures in the a/c lines equalizing after you shut the car off. That's normal. The idle symptoms might be a sluggish iac. You might want to have it cleaned. It wouldn't hurt to take the battery terminals off and clean them for the window issue. Might all be normal though.
 

Miller220

Member
Sep 12, 2009
36
0
6
Mar 15, 2010
#8
  • Mar 15, 2010
  • #8
Thanks for all the responses guys, sorry for not posting sooner...I pulled an all nighter and woke up a little while ago...looks like I'm off back to bed At least I'll sleep better now G'night gents.
 
D

Deleted member 38176

Mar 15, 2010
#9
  • Mar 15, 2010
  • #9
1. My car does that too

2. Yup, it also does that

3. Sounds normal

4. You need to freakin' relax and stop worrying so much lol
 

nancygrl

Member
Nov 25, 2009
257
4
18
Mar 16, 2010
#10
  • Mar 16, 2010
  • #10
+1
 
0

007

Founding Member
Jan 29, 2002
3,287
24
69
Broke
Mar 16, 2010
#11
  • Mar 16, 2010
  • #11
My car has started doing number 2! Mine will actually cut out. I changed the IAC. Nothing. When you say "clean the IAC" what exactly are you cleaning?

D
 

trombonedemon

Well-Known Member
Jun 25, 2009
1,962
39
59
U.S.A, U.S.A., U.S.A.!
Mar 16, 2010
#12
  • Mar 16, 2010
  • #12
Cleaning the IAC is kinda pointless, its something you need to replace if malfunctioning, cleaning it w/a solvent would probaly worsten the function!
 

deftsound

Please ask me how much my supercharger cost
Apr 6, 2004
945
1
39
Texas City TX
Mar 17, 2010
#13
  • Mar 17, 2010
  • #13
All normal...don't lose any sleep over it!
 
I

IvyMike

New Member
Dec 20, 2009
26
0
0
Huntington Beach, CA
Mar 17, 2010
#14
  • Mar 17, 2010
  • #14
trombonedemon said:
Cleaning the IAC is kinda pointless, its something you need to replace if malfunctioning, cleaning it w/a solvent would probaly worsten the function!
Click to expand...

Actually, mine froze up about 6 months ago. Took it off and cleaned it up with some carb cleaner, put it back on and it purrs like a kitten. Took about 10 minutes. Haven't had a single problem with it since then.
 

AdRock

Member
Nov 13, 2003
521
1
19
South Texas
Mar 17, 2010
#15
  • Mar 17, 2010
  • #15
trombonedemon said:
Cleaning the IAC is kinda pointless, its something you need to replace if malfunctioning, cleaning it w/a solvent would probaly worsten the function!
Click to expand...


Cleaning it will not make it worse. I've cleaned so many with carb cleaner that I've lost couont.
 
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