Loud Hissing At Startup...

[04z71steve]

hey guys.. kind of like the title says! i have a very loud hissing noise at startup.. I've been hearing the sound for the last few days now and i haven't had a chance to look but what could it be?

 

all i can say is that it sounds like a loud hiss.. and when it idles it sounds like somethings wrong too... sounds very weird take the hiss and turn it into a low steady noise and thats what i hear.. has anybody had any issues like this before with the 04 5.3's?

 

give me some opinoins... what could it be?

 

thanks, steve

[04z71steve]

anybody?

[Bish]

Vacuum leak? AC Compressor? Tough to communicate a sound through text. Can you record it and post what it sounds like?

[Rocco715]

Loud hissing sounds like a vacuum leak

[sillyazz]

Hose come off the brake booster? Brake pedal hard? Hose off of pcv valve? Sounds like a vaccum leak.

[04z71steve]

i have no idea... its sounds weird i'll try and record it in the morning... its MUCH louder then usual! sounds almost like a huge air spirt right as i start the rig...

[redsled2007]

I've been hearing the sound for the last few days now and i haven't had a chance to look but what could it be?

 

Without sounding like a jerk, why is it you don’t have time to check it out, but you do have time to log on and ask what we think it is.

 

Please, go out and look. You’ll more than likely be able to pin point where it’s coming from (at least an area). Then maybe we can give you more than a guess.

[K.Jump]

Yeah definately try to narrow the noise down. If it sounds like it is coming from the back, I bet it is the fuel pump. On mine the gas gauge would only work sometimes,then I noticed the loud hissing noise. Next thing I knew I was replacing the fuel pump. Good Luck and let us know what you find.

[04z71steve]

lol yeah so much for sounding like a jerk.. thats alright tho.. i can see where your from and i could see how it would be easy for you to throw your shoes on and walk outside to check it out...

 

me on the other hand... i'm not sure if you checked but i live in the south suburbs of chicago... it was 23 at the time you made your "suggestion"

next it takes 2 seconds to log on here... plus i'm not sure if your familiar with this... but people actually do have to wake up at 3:00 am to go to work sometimes... so running outside with my digital camera and a jacket at 11 pm wasn't really an "option"

 

i'm at work still right now but when i get home i'm gonna get out my digital camera and record it...

 

 

 

i was just opening up the issue.. so people knew about it so when i finally got the sound ... you guys would already be familiar with what was going on... but next time i'll make sure to get a scan some digital pics of my dirty hands and the video for you... before i make a sound here... \

 

the sound is definitely coming from under the hood... its right as i start her up she sounds almost like when u let off a burst of pressure on a air compressor...

 

thanks for your suggestions i'll definitly keep an eye out when i'm under the hood today! i'll get the sound clip on here ASAP!

 

thanks again, steve

[04z71steve]

startup:

 

 

 

rev:

 

 

you can sort of hear it jingle after the rev... but

 

sounds like the trucks only gonna do it on startup... guess once it gets warm whatever it is thats wrong isnt a problem anymore... what could that loud hiss be tho? it comes from under the hood... its got like a squeel/ burst of air sound to it... where should i start to look first?

 

thanks, steve

[Bish]

I'll give you credit for going out in the snow to record it I've been in my garage putting a couple coats of Zaino on my new ride before going out in the elements. That stuff is pretty amazing IMO.

 

Unfortunately I'm afraid I can't be of much help. Only on startup implies it is not a vacuum leak as I would think it would do it all the time. Fan clutch? I know when my clutch started to go, it would be locked full on when first started up in the morning then would go away after a minute. You sure it is air? Could be alternator bearings starting to go. Mine would actually squeal a bit when it was getting tired.

 

Good luck. Maybe others will chime in.

.

 

BTW-I wouldn't take anything here too seriously. Most people are good folks trying to help. I have learned and shared lots of info here. One thing about typing, you never know the persons expression or state of mind....just the text. Always a few trolls but like I said most are good people

[sillyazz]

Sounds like a bad bearing. Maybe the Alternator?

[04z71steve]

"BTW-I wouldn't take anything here too seriously. Most people are good folks trying to help. I have learned and shared lots of info here. One thing about typing, you never know the persons expression or state of mind....just the text. Always a few trolls but like I said most are good people cheers.gif"

 

 

 

yeah i hear ya... i just get a little aggravated when people criticize me without knowing the situation.. but whatever I'm over it.. so its all good.. no hard feelings..

 

 

well its funny you guys mention the alternator because the other day i was sitting at a red light and the alternator gauge was moving left to right... i do have a sub in my truck but it definitly wasn't pulling anything cuz it wasn't even on.. so maybe there is something up with the alternator?

 

thanks for the opinoins guys keep them coming!

 

my dads cleaning his rig up but i'm hoping to get mine in the garage in a bit..

 

steve

[Draenor]

Sounds like a bad bearing.

+1

[slimjim2525]

This is gonna be a useless post but what the hell. It's amazing that those who "don't want to sound like a jerk", often sound like the biggest jerks. Sorry I can't help you with your problem, i did listen to both of your recordings, but it was hard to hear what you were describing.