bizarre ghostly jet-engine whining noise [Archive] - GrandAmGT.com Forum

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gr8gt
11-30-2004, 09:01 PM
Bought a used Grand Am GT. V6, auto. High mileage, but very nice condition. One owner, well-maintained. A no-replacement air filter had been installed. Fluids changed on schedule. Car had been sitting for about a month and a half. Test-drove it in the rain, highway and city, with no problems. Had it inspected. Only thing mechanic mentioned was some dampness in the power steering system he told me to keep an eye on (and the a/c coolant had leaked away, but I knew that.) So I bought it.

First time I drove it extensively after that was again while it was raining. After a while, a weird high-pitched whine began to creep in when the engine was shifting. It would fade in and out, quietly at first, then sometimes quite sharply.

Next time I drove it, it was dry out. No whine.

Next time I drove it, it had been raining, and the whine returned, but it stopped raining, and after a while, the noise went away.

Next time I drove it, it was raining, and lo and behold the whine returned.

So, I only hear the noise when:

1. It is raining and the car is wet
2. The engine is in drive and I am moving
3. The engine has heated up all the way.

Noise only occurs when all three conditions are met. I have tested it. It sounds like a high-speed airplane engine warming up or slowing down or something. Could be sound of spinning metal, or metal on metal, but is not harsh--very smooth noise, sometimes faint, but sharp at times. Have read suggestions elsewhere it could be a pump or filter. Maybe also a *very* faint gear noise, like it was a manual in reverse? Hard to tell, I may be imagining it--and if present, this noise also disappears whenever one of the above conditions does not hold.

Previous owner never heard this. Only suggestion was leaks on the fuses, but it does not sound electrical--it clearly sounds and changes pitches when car is shifting up and down. When at rest, there is no noise, even if engine is revved in Park.

Mechanic couldn't diagnose anything over the phone, and so far it hasn't been wet during the day, so I have nothing to show anyone if I take it in!

Any ideas???????

atc3434
12-01-2004, 12:29 AM
To understand better, this noise is only when shifting, or all the time, and you know its based in the motor somewhere because it changes with RPM, not vehicle speed? Assuming its the latter, and somewhere in the motor, my guess would be an accesory, such as an alternator, a/c, tensioner, or waterpump bearing. The wetness probably agravates the condition enough to the point where its audible.

OK, two mintues later I'm re-reading your post, and you say it only occurs in drive. Probably rules out everything I just said. Only in drive, its almost gotta be the tranny. What exactly, I dunno, but if it changes with shifts, its obviously not on the final drive side of the tranny. Perhaps the torque converter or something of that nature. When is the sound the loudest, the sharpest. If coasting in neutral, can you reproduce the sound? It won't reproduce when the engine is cold, correct? That being said, it makes me think even more torque converter, and perhaps something to do with the lockup, since you only get it when the engine is warm, and subsquently your tranny will have reached the temperature where torque converter lockup is allowed by the PCM. Interesting. That all I can think of for right now, hope that gives you at least a few things to consider.

gr8gt
12-01-2004, 10:55 AM
Only in drive, its almost gotta be the tranny.
Seems like it, though I've read it could be a pump or a filter or something. Took it to the mechanic this morning, couldn't determine what it was right away, but we noticed the air pump wheel was just a little noisy in park. Will be taking it in next week for a closer look.

What exactly, I dunno, but if it changes with shifts, its obviously not on the final drive side of the tranny.
Yeah, it feels like it's shifting smoothly. Going up hills, it doesn't shift into 3rd (2nd? 3rd I think) until 3K revs, but I think this is normal. Otherwise it shifts around 2400-2500 revs. No skipping, slipping, popping, etc. Normal operation. Some extremely light thumping maybe, but this sounds like a very slight wheel alignment problem, not related to the engine. May only sound when gas is being applied, but maybe not. Hard to say. Anyway, I think it's unrelated.

Perhaps the torque converter or something of that nature. When is the sound the loudest, the sharpest.
Thanks, I'll mention it to the mechanic next week. It seems loudest when accelerating from stop through 1st--it can really start to shriek for a second or two, then vanishes.

If coasting in neutral, can you reproduce the sound?
Don't know, I'll give it a try.

It won't reproduce when the engine is cold, correct?
Yes, though this morning the engine was warmed up in Park to about 100deg (maybe a little more), and I heard it once I started moving. Previously I had only noticed it at about 200deg. But I'm pretty sure it doesn't sound if I start driving right out of a cold start. Also it wasn't raining out, but there was melting snow on the car? Not sure if this is related. Engine looks dry.

That being said, it makes me think even more torque converter, and perhaps something to do with the lockup, since you only get it when the engine is warm, and subsquently your tranny will have reached the temperature where torque converter lockup is allowed by the PCM.
Ok, I'll keep that in mind, too. Thanks.

sc02grandam
12-01-2004, 11:38 AM
you sure you dont have a blower ? lol

tintin
12-01-2004, 12:18 PM
This may not be the same thing but have you ever hear this noise at about 90KM/h when at constant speed on watery roads? Does your car have the original good year tires? It may be loader and constant on a well watered road and at the right speed. I have noticed a noise like you say and found that it was my tires on wet road.

gr8gt
12-01-2004, 03:44 PM
This may not be the same thing but have you ever hear this noise at about 90KM/h when at constant speed on watery roads?
Yes, I think...

Does your car have the original good year tires?
On the front, no, they're Dunlops, but on the rear yes, they're Eagle GTs (but the noise is not coming from the rear)

I have noticed a noise like you say and found that it was my tires on wet road.
Thanks, I'll keep that in mind (though it seems too loud at low speeds to be tires). I drove around again this afternoon, after everything had dried up. No noise! So it seems like it must be moisture-related (somehow?) MADDENING!

Maybe there's, um, condensation on a belt or wheel or joint when it's wet, related to the tranny, and that's somehow causing audible friction??? Wonder if some sort of lube job is all it needs.

jsshears
02-27-2005, 11:30 PM
gr8gt - I had the noise as you have describe in your car. Have you checked the wheel-bearings? I took mine to a mechanic, and the problem was with my wheel-bearing.

Ridenour
02-28-2005, 02:22 PM
Resserected a 3 month old thread :(

Kdawg207
02-28-2005, 02:28 PM
guess the noise isn't that bad lol