I need some help here...

92Frankenstein

New Member
Apr 25, 2004
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Minnesota
I have a 1992 2.3 convert. with automatic overdrive. The motor and trannys how no problems and run real strong, but it makes a strange humming noise when idleing, it sounds like it is coming from the cat. converter, but I am not too sure..

Also, when I am driving or stopped, and i turn on the heat and headlights and so on, the current drops.. causes the headlights to dim, I am not sure which is causing this either.. And it only does it sometimes it seems like!

Thanks for all your help, Brian. :shrug:
 
Thank you

I will try the alternator first, they are cheap enough at the junkyard... But the noise isnt a whining, its more of.. its hard to explain.. like two pieces of metal very close vibrating against each other... Someone told me it was the cat, but I have no idea.. Thanks for all your help guys (and girls) :D
 
At idle, turning on various lights and accessories will cause them to dim a little. Try giving the engine a small rev, and you'll see the voltage jump.

It sounds like it's coming from under the car? Like, the engine bay, or in the middle somewhere? Maybe a bracket or mount is loose and vibrating.
 
Yea, the voltage goes up when I rev, so I will deal with that

It is hard to determine where the noise is coming from, but from the best of my knowledge It sounds like it is coming from the back of the motor, and it is only at idle, when i rev it to about 1000 RPMS it gets faster and as soon as i hit about 1200 RPMS it goes away, and i never hear a thing when I drive.
 
Ok seriously I'm going to stop being a post whore, youre alternator is dying but you do NOT need a 3G alt. Just get a 75amp either new or from the JY. I personally would go with new. The reason I say that you do not need a 130 amp alternator is that I have a 65amp with over 3000watts of stereo equipment, and alot of little stuff drawing constant power(glo gauges, TV, etc.) and I experience no dimming. The noise you here from under the car is you cat's heat shield. Here's what to do, take a nice sized pair of pliers and jack your car up(or shimmy underneath) on top of your cat there will be an extra sheet of metal, one of the welds has broken and is causing the noise/vibration just rip and tear at it until you get it off. It is not a big deal to not have it and will only take 3 minutes for the whole process.
 
If it's a humming/buzzing noise and it's coming from under the car, check your transmission fluid level.

WHen the fluid starts getting low, the tranny sometimes buzzes. It usually will buzz if you shift from D to Park
 
Thank You All

I will try all these things, I will check the tranny, which I am pretty sure is full, and i think the heat shield on the convertor sounds like my best bet... I will check that out tommorow, if the noise doesnt go away... I will let you know as soon as I get it all figured out.. thanks. :nice:
 
Yippie!

It turns out the humming noise was the heat shield on the cat... no more noise! thank god... I am going to the junkyard today to pull a bunch of mustang parts and grab an alternator. I went yesterday and got 89 GT seats with power lumbar, two new mirrors, GT black taillights and a nice hood with no rust, dings, or dents... so im a happy camper and I am even going back for more! thanks to all for your informative help... :hail2: :hail2: :hail2: