high-pitch "whine" when stepping on gas

[lostatlantis]

hi all,

I've searched and read through lots of threads but haven't found anything quite like it. The problem is a fairly high pitch whine coming from the engine bay whenever I step on the gas (while in driver's seat, seems to originate from front right side but not sure).

The car in question is my '96 firebird, stock v6 auto w/ y87. She's been garaged for two months before this drive. I took it to a trusted shop and prelim inspection shows good belts and full fluids. The mechanics confirmed the noise, so it's not in my head. I wonder if it's fuel pump, but he said it would be a constant whine if that's the case.

Incidentally, I noticed that my A/C would slowly decrease in air intensity and velocity - after 20 mins or so, the air would really decrease and I would have to keep turning it up. It seems to be not as bad on cooler days/evening. I didn't have time to check the A/C at the shop. Low freon? Not sure how this would cause the whining noise though.

The whine almost sounds electrical in some way, like capacitor charging up. The thing is, it comes on ONLY when I step on the gas.

Also, this one might be in my head, but I feel like the car is slower than usual - reving to 3000 rpm and it takes longer than I remember to gain some speed. The overall feel somehow reminds me of when the family van's transmission was dying.

Thoughts on how to attack this?

[Nikos95]

Re: high-pitch "whine" when stepping on gas

hmm very odd, only thing I can think of and makes minor sense, if maybe your alternator. Pop the hood while its in park, and grab the throttle cable, give it a few rev's see if you can pin point the location. :-/

[UDLOSE98]

Re: high-pitch "whine" when stepping on gas

yea, my alternator makes the same whine, I claim tht my alternator is turbo'd and that solves the problem.

[BLLDOGG]

Re: high-pitch "whine" when stepping on gas

if he was such a good mechanic he should have told you what it was. I know it has already been said but here is a thought, pop the hood and listen. get a rubber hose, put one end to your ear and the other to things in the engine bay. I would start from the alternator then go listening around stuff like the idler puller, water pump, etc. Just listen for a difference in sound. It should be obvious when you come across the problem.

[Camaro Dom]

Re: high-pitch "whine" when stepping on gas

i have the same whine too. i always attributed it to my RAI. only problem is tho blldogg, it only happens when its under load so unless i were to get on a dyno there'd be no way of figuring it out. and yeah, i get rediculously crappy acceleration under 3500 rpms. in second gear (auto) it just sucks until i hit like 3500-4000 rpms then it really pulls me into teh seat. its really weird....

[av6xperience]

Re: high-pitch "whine" when stepping on gas

dont our cars have an a/c pulley? if so im willin to bet its that or another pulley

[Nikos95]

Re: high-pitch "whine" when stepping on gas

dont our cars have an a/c pulley? if so im willin to bet its that or another pulley

Um if you have A/C you have a pulley on it :)

Personally my tensioner is squeekin a bit, but I am dealing with that.

[matt3989]

Re: high-pitch "whine" when stepping on gas

first I'd look at the tensioner, over time the springs get worn and it they become too weak, if that is the case you can try kicking the tesioner up by hand (just use a 3/8 in drive ratchet and push it clockwise) if that solves it temporairly youll need a nw tensioner sooner or later

if that doesnt work you could take your car to your mechanic, or local auto parts store and have your alternater tested

and if all that fails you should find a better mechanic who can tell you what the problem is

[lostatlantis]

Re: high-pitch "whine" when stepping on gas

To be fair, I didn't give the mechanic much time to diagnose the problem. I just moved to a new town, and that was my old mechanic back home. Still trying to find a trust worthy shop here in Raleigh-Durham area :( I am welcome to suggestions if any of you are from or in the area!

Anyway, I took it to Advanced Auto today, battery is good - but I forgot to ask for a OBD code read - think that would help, even though there's no warning lights on? The guy did confirm hearing the whine though - he asked me if it's supercharged LOL

Also today noticed another issue... very strong gas smell, it's always ran a little rich but this is definitely more pronounced than before. O2 sensor good place to start?