Whine from passenger side outside

[Edman]

It seems speed related, but not engine speed or load related. Comes from the passenger side exterior (like the air inlet in front of the rear wheel?). It's especially noticeable going past a wall or other sound-reflective spot, where I'd normally enjoy the sound of the engine. Is there a fan in there that needs lithium grease or something? I searched the site and googled, but I can't find anything. Any help appreciated! Thanks!

[systech]

It seems speed related, but not engine speed or load related. Comes from the passenger side exterior (like the air inlet in front of the rear wheel?). It's especially noticeable going past a wall or other sound-reflective spot, where I'd normally enjoy the sound of the engine. Is there a fan in there that needs lithium grease or something? I searched the site and googled, but I can't find anything. Any help appreciated! Thanks!

There are fans:

1. in the engine compartment on the RHS, to vent the hot air from the compartment and

2. behind the radiators at the front. They come on when the coolant tempertaure is up, and particularly when the AC is on.

Note sure if either can be quietened as you suggest...may need to replace the noisy culprit !

[Edman]

Okay, the sound is still there.. It's almost a whine. I've had a friend lean over the side and cover the vent for a second, and the sound doesn't change. It's coming from the rear wheel. Could it be a bearing or something? I've never heard any car make this sound. Dealer was useless (for once) and told me it was the tires - this is NOT the tires... Any thoughts?

Edited May 27, 2008 by Edman

[juniinc]

As systech mentioned there is a fan blowing thru the passenger(US) side air duct.

fan shouldn't come on when U Start the car cold, wait until the engine compartment fan comes on to listen or disconnect the fan ?

down the hill, put it in Neutral, turn off the ignition,let it roll for a few seconds to listen?

[sc00ter18]

Did you make sure it doesnt make this sound when the car is in park??

it could be a lot of things unless you know exactly where its coming from.

[Ross1]

Okay, the sound is still there.. It's almost a whine. I've had a friend lean over the side and cover the vent for a second, and the sound doesn't change. It's coming from the rear wheel. Could it be a bearing or something? I've never heard any car make this sound. Dealer was useless (for once) and told me it was the tires - this is NOT the tires... Any thoughts?

If the sound varies with speed, then it's most likely your wheel bearing! Jack up your wheel and spin it to see if you can here a noise. You might need to jack up both rear wheels to compare the difference.

[Edman]

I have verified that the sound is still there, even with the engine off and the car in neutral. (Thanks for the suggestion, juniinc!). It doesn't seem to vary much with speed, but I did also notice that it starts between 15 and 17 mph on acceleration and seems to stop right around 17-19 mph on deceleration. It's a very abrupt change from no noise to noise - it's not a gradual buildup or increase in volume.

I still wonder if it's the bearings, but I've never seen or heard a bearing problem quite like this.

Edited May 28, 2008 by Edman

[timbo]

Should you have wine and drive?

[juniinc]

No problem Edman!

at least we know that it's not the fan,,,,

possibly emergency cable rubbing or the wheel bearing?

[Gengus]

Sounds the same as the rear bearing I had replaced on my 04 986. That confused the garage too, but it was indeed the bearing. Not a typical bearing noise - like you say, a mid to high pitch wine at around 15 mph, disappearing at higher and lower speeds. My garage was a little reluctant to change the bearing, but they did, and that sorted it.

Ian

[Edman]

I took the car back to the dealer garage for a second trip a short time ago. I grabbed a mechanic and took him out for a ride, so he could hear it. At the time, he said it wasn't a bearing but he didn't know what it was. I made an appointment and left it in.

They came back saying it was the brakes, and that I needed new pads and rotors. I asked if the rotors could be turned and he said no. I told him I'd take care of it. The rotors were grooved a bit, but not too deep. I ordered Pagid pads and one sensor (it had just come on). I had the rotors turned at the local Big O.

Problem solved. Dang strange. Still, the bill at the dealership would have been almost $700 (two rotors at I think $193 and the brake job at like $250). All told it was $93 for the pad and sensor, $24 for cutting the rotors, an $10 for a trip to the ice cream shop with my wife for washing all the clothes swathed in brake dust.

Edited June 24, 2008 by Edman

[Roadster 986]

Problem solved. Dang strange. Still, the bill at the dealership would have been almost $700 (two rotors at I think $193 and the brake job at like $250). All told it was $93 for the pad and sensor, $24 for cutting the rotors, an $10 for a trip to the ice cream shop with my wife for washing all the clothes swathed in brake dust.

This was interesting and timely information; my 02 has virtually the same symptoms. Mine seems to be on the driver's side; a whining noise that becomes noticeable around 25 mph on acceleration, and disappears at about the same velocity on deceleration. Just loud enough to be irritating in that I know something isn't quite right. A lot of searching this site previously had me thinking a bad air/oil separator, or as you had been suspecting a bad bearing. My first hunch, and the one that seemed the most plausible was brakes so I'm encourage learning that was what you verified to be the source.

I had already jacked the car up, checked bearings for unusual feel or noise, and pulled the wheels to inspect the brakes but found nothing that seemed to indicate a problem. The pads are far from being worn down, and the rotors are only slightly grooved as you mention. I guess the AOS project can be put on the back burner, and brakes moved forward – thanks for the follow-up!

[sonny2]

I had the same kind of whine on my '03 S 6-spd with 26k miles on it that would come on >25mph & got louder as the speeds built. Got to the point where people driving next to me on the highway would look over in disgust. I had my Wife drive next to me to try & pinpoint where the whine was coming from & she said it sounded like the rear px side. It was either from the vent or rear wheels.

I jacked up the car & placed it on jackstands, took the wheels off & spun everything that would spin & looked at every piece in the drivetrain that would move. I even ran the car through the gears while on jackstands to see if I could replicate the sound but was not able to. Took the cover off the vent & ran the car until the engine got nice & warm but still no sound. The brakes & rotors are fine. Nothing I did would replicate the whine except while driving >25mph.

After ~500 miles, the whine stopped. The car still drives fine & I've done the above again since the noise stopped & I can't spot anything that looks/feels different on the car.

I'm just crossing my fingers it doesn't start again or something catastrophic happens (which I doubt :unsure:)

[Roadster 986]

As a follow-up to the whine heard and referenced in this thread - today I completed rotor and pad replacement on all four wheels. Taking it out for a 40 mile shakedown cruise, I am happy to report that the whining noise is gone. I don't have a micrometer handy to get a good measurement just yet, but the rotors are probably worn ~ 1.5-2 mm each side (yes - out of spec). The ridge along the periphery of the rotor is what I believe caused the whining or “scraping” noise, as it wedged the pads into the wider groove worn into the rotor face.

As for the brake job itself, let’s just say it is a joy to work on this vehicle.