I searched this and read a bunch of posts about the sudden onset of a whine from the engine compartment but no one described the sound coming from the upper intake area.

Mine's the annoying pitched whine or whir but it honestly seems (from just putting face near different spots atop the motor) to be emanating from the center of the upper intake, maybe even the rear cylinder bank beneath the upper. It's clearly related, based on pitch changes, to engine rotation and RPM.

Any thoughts?

Unless there are some really odd sound deflections going on, I'm confident that it's not the alternator, the AC compressor, the tensioner, or a belt.

'99 SEL, 104K, automatic.

 

does it sound like it could be caused by air whistling, or is it a noise caused by something mechanical? a lot of times these cars with intakes will have a whistle. both my old 96 and my current 95 with 3.5 in it have (had) this.

 

Had it, was a tensioner. check that first, Swear!

 

I suddenly got this too. I did Amsoil ATF conversion of the PS and AT 3 weeks ago. Today, I drive the car several times. Last trip, drive it to about 20 miles and park. Then decide to back into the parking spot and fire it up and there is this whine that wasn't there a minute ago. Start it up and shut off a couple times and then just back it in. A couple of hours later, when I got back, the whine was still there. It was very suddent and seems to be coming from the upper intake towards the PS side. I am not sure if its the PS Pump as I did drive the car all the way back. With a slight smell of burning rubber. I eased it back home and am now looking on ways to troubleshoot. Do I just take it in to an indy?

Since the onset of the whine it idles abot 300 RPM higher and makes the whine like its the transmission. Can it be the transmission and can it go just like that even though the sound seems to be coming from the passenger side and I believe the tranny is on the driver's side.

 

you would be right, trans is in front of you. the whine is annoying, i hear it more now that its colder. dont think its a tensioner, more an upper intake or loose hose somewhere on the block. im leaning towards the exhaust whining.

 

i'm about to end this thread.

lol... turn off your radio/ipod/whatever and see if the noise still happens.

if it stopped, i'll explain why. if not, i'm a jerk. lol

 

Well, atleast for me, the radio was off. So, you're a jerk already. Lolz.
I don't see how the whine can come from the engine compartment and the RPM rise with a radio or an iPod on any way you jerk.

 

How are you determining where the whine is coming from? I had a sudden whine from my engine bay and I though it was a bunch of things until i used a long screwdriver and touched the tip to my alternator, while putting the handle end in my ear. I quickly found a bad alternator bearing, which failed three weeks later. Not saying its your alternator, just use something solid as a kind of stethiscope instead of relying on the air to transfer the sound to your ear.

 

Thread not ended.

It's the motor.

I'm ignorant, not stupid. 'Er maybe I'm stupid but educated. Oh, I don't know...

It's not the audio system and the whine can't be distinctly heard from inside the cabin. I've got the audio system whine and this ain't that.

 

Well, I can hear it real good with the hood open.

As far as pin-pointing it, I'm just leaning over the engine trying to determine frm what area it's coming from.

Best I can tell based on me leaning over the motor is the rear portion of the upper intake or just beneath.

I have not taken the stetho to it yet.

 

Same here. Haven't used anything to determine where its from. Since for me the RPMs jumped a few hundred in both idle and stopped at lights, I am sure its one of the bearings or tensioner and I think the idea of using something to channel noise to isolate what's whining is a good idea.

 

Thanks for the advise. I will try that. I also suspected the alternator but haven't tried what you said as I am being too lazy and have an extra car at my disposal. So, I just parked the maxima and now I drive the minivan (garage queen) to work.

 

lol, i'm just saying.

if you search my old threads, you will see me asking the newb question, "whoa, is my car turbo'd?"

turns out, since i use my head unit's aux port for my iPod, i had a habit of turning my ipod off, but not my HU. i would notice a whistle/whine coming from my intake manifold. the "pitch" would rise with my rpm's. i was dead convinced it was from my intake manifold. turns out, someone mentioned making sure my head unit was off. that's what it was.

i wasn't ACTUALLY trying to be a jerk, by the way lol. hope you find the problem

 

It can be the swirly valves that are whining with a high pitch.

 

If the RPMs are higher than normal, and you have a whiny-squeely sound perhaps the computer is compensating for a vacuum leak. If you open the throttle quickly (at the butterfly) does the sound briefly go away and then come back?

I thought feedback through the audio system was a good thing to check too.

 

I hear ya and thanks for the clarification but it's definitely something in the engine.

Lost a wheel bearing over the past week so the whine investigation is gonna have to wait. If and when I find it and kill it, I'll let you know.

 

Mine's the alternator so it seems. It started smoking the other day when I tried to move my parked car into the garage. The car's been grounded since the day this whine started. I also put a pipe on the alternator and it was the thing whining and then it started smoking and there's was a small fire inside the alternator when I moved the car into the garage.

 

Did you ever fix the whining problem?

 

im having this same problem as well...its like a mini scream. my tech told me it could be an injector leak. but im leaning towards the alternator theory seeing as mine is going bad.

would the bad bearing affect the alternators ability to hold charge???

 

It could be brushes are going bad also... To help assure it's your alternator take long handle screw driver and touch a metal part of the alternator and listen with the ear to the handle... do this while the car is running and be careful not to touch any moving parts. If you hear bearings or bad brushes it's your alternator. Any malfunction of an alternator can affect your charge.

 

A plenum gasket leak might be audible, and certainly raise RPM.

How would the HU cause noise at the intake? I believe you, but please elaborate.