oddwraith

iTrader: (1)

Okay so here are the symptoms;

I have noticed on a few occasions that my car will make this noise from time to time and when in the Tim Hortons drivethrough it's ear piercing! Lol. It however typically will totally stop if I turn the ac on. Also it usually goes away after a short time. I have noticed also that if the car is not making the sound in question, by starting the ac and then turning it off again sometimes awakens the beastly scream! Which again usually stops after a vehicle restart or some short time.

*possible contributing factors?

-cars headlights pulse dim/bright when first started for a few moments. Will brighten up and maintain with a simple shot of throttle. Then all is well.

-as per other thread: car seems to lose it's battery connection from time to time and I must tighten the red terminal to ridiculous levels to get contact and then it instantly fires up and runs great.

side note:
car runs perfect and strong other than these weird sounds etc. Other than the inconvenience of the battery contact not being all that great, the car seem to run like new.

So any ideas what this noise is? Is it maybe normal, ac pulley? Hmmmm?

Thanks again guys.

marors1

iTrader: (1)

the noise you are talking about is probably the AIR pump or the air check valves. It is supposed to run for something like 6 minutes after startup and when it thinks it needs emissions air added to the exhaust.

The battery thing, you may want to take the connector apart and clean it up. Just pull the stud out of the connection and you may be able to slide the red boot off the end and clean it up.

Sometimes alternators don't kick in right away, and after juicing the throttle they work and settle in charging. I can't say I have seen this much in newer cars, but I saw it occasionally on older vehicles. That may be your issue with the lights being dim off the bat.

Just some thoughts.

D

NonGoggleGuy

Yup, probably the AIR system.

Ryanmgaspard

iTrader: (6)

Mine hisses too and I don't have the AIR system?

NonGoggleGuy

You have an air leak somewhere else then. Maybe a loose I/M or vacuum hose.

99RTA

iTrader: (-1)

Check for snakes under there? i think you are probably just hearing the air rush by the throttle body opening. Don't worry about it.

sdm1234

iTrader: (8)

The sound you are hearing may either be the alternator whining (it's going bad) or a bad A/C clutch. Those are the only two things I can think of that have any relation to the A/C being on/off or the electrical system malfunctioning.

oddwraith

iTrader: (1)

Okay well let's assume it IS the alternator, which would also help explain the dimming/brightening of the headlights during the first few moments after startup. Why would that sound go away after turing the AC on, and then start again afterer turing AC back off?

It seems to correspond directly to the AC being turned off and on. If when I first start the vehicle, the AC is off, this sound isn't likely to present itself. However, if I turn the AC on then off again, the sound is there until turning the AC on to silence it. It's not THAT loud, but when I drive through a drive through (that seems like a waste of words lol) I can't help but notice it. Thanks.

oddwraith

iTrader: (1)

Well I went ahead and looked for snakes and you were right! I found one lurking in there, so I grabbed it and tossed it off into the ditch. I noticed right away though that my vehicle wouldn't start after this. It turned out the "snake" was a wire and I don't even know which one it was. Thanks for the advice jk lol. It's definitely not the tb air I'm hearing. Imagine a LOT louder, and MUCH higher pitched.

oddwraith

iTrader: (1)

I don't know if "hissing" is the term I should have used perhaps. More like a screeching/metallic type sound I guess. Not idle or throttle affected either.

It's almost as if two metal 1/2 inch washers were quickly rattling against each other on a bolt. Than when the AC is turned on it's like someone tightens the bolt and the two washers go silent. I hope that gives a better idea of the type of sound I'm hearing. I'm not sure that it's even serious enough for me to be making a big deal of it really either

Also it sounds like it's coming from the driver side of the engine bay from inside the vehicle. From the engine bay itself it just seems to echo and give no real hint as to where it's coming from?

Soul Crusher

A/C compressor clutch is going bad? Hanging, catching, dragging?

99RTA

iTrader: (-1)

hmm how bout the engine pully on the crank? Is the bolt that holds it on tight?

95TAJade

iTrader: (4)

check the little PCV type valve that runs along side the main harness on the passenger side of the engine bay. I had a vacuum leak where that little check valve plugs into the three tubes. This thing is what controls the vacuum system for your AC vent selector. Mine stated to get brittle so I had to fix it with a little plastic welding But check that cause my car hissed like a pissed off snake for a while before I fixed that.

oddwraith

iTrader: (1)

I'm still hearing this metallic sound I've been talking about here and have no clue what the hell it is. Every once in awhile it happens, like I said in my post a few posts up the page.....two metal washers is what it sounds like.