Whining Noise When Accelerating

[94EddieBauerRock]

I have done some searching but haven't found anyone with the same problems as I have.
When I accelerate there is a loud whining sound coming from the transmission/driveline area. It only makes the sound when I accelerate and when I am cruising. I don't notice the sound at speeds lower than 40mph. It is a very annoying humming whine. When I let off the accelerator the sound goes away. The transmission seems to be shifting fine. I checked the tranny fluid (warm engine, flat surface, idling), it seemed a little low so I added some. This didn't help anything.
I am no mechanic but have some theories.
-Transmission?
-wheel bearing?
-Front axle?
If anybody could give me some help I would really appreciate it. Also wanted to mention that I searched for a vacuum leak and didn't find one.

 

[91ROKKRAWLER]

check your fan blade. it may be locked up if its coming from underhood. when its off and warm, it should turn fairly easy. when cold it'll be a bit harder to turn. also when its running you'll feel a lot more air going towards the engine. have someone rev it while you are lookin and you should be able to pin point where the sound is coming from.

 

[94EddieBauerRock]

Thanks for the info. I'll try that. The sound doesn't seem to occur unless I am moving though. I'll try what you suggested though..don't think I've listened to it rev, just idle.

 

[matts91XLT]

mine is a five speed and wines in every gear except 4th. when in accelarating. i was told it was normal since the trans had been rebuilt and beefed up.

 

[RobClay]

My 02 explorer sport also has the same problem, it runs fine.
Just when im up in higer speeds above 40mph i get this humming noise when accelerating, but when i take my foot off it stops completely. Cant figure out what it is.

 

[doonze]

There's a good chance your gears got warm once and pitted, or warped slightly. More or less that's what makes the manuals whine for some people. The auto's have gears too, and the same thing can happen.

In the manuals, it's often because:

A.) Someone ran it low on fluid as some point, or it is STILL low on fluid. They heat up when low and whine. Once they start they never stop, the gears now will wine no matter what. I heard that some people have gone over 200K with the whine and been ok. Others have had the manuals fail after 200 miles once it started whining. I guess it most likely depends on if the cause is still there or not. In other words if it's still overheating or not. In an auto if the problem is still there then most likely you not going to be moving at all. So I would say it was a past issue. When did it start?

B.) They just plain flat overworked it. The manuals are much less likley to overheat, but they can. They have no cooler so if you overwork it big time (think long uphill towing way over limit) then you get the same affect as running it low on fluid.

Now I honestly haven't heard the auto people complain about this. But in the end a gear is a gear. My guess the lack of reports from auto owners is because the autos stop working once they are low enough on fluid to pit/warp the gears. In other words they fail before they get to that point unlike the manuals. However I guess in some cases it could happen though. Or it was toasted, then they rebuilt the clutches so it goes again, but the gears whine. That tranny ever been rebuilt?

As far as beefed up goes, I do know that some "beefed up" rear ends will whine. My other hobby is my trans am, and it's a built autocross car. Some just whine it if it's lashed wrong (messed up install). But some "super tough" rears whine, no matter what you do. In the end a rear end is just gears like a tranny. So if a rear can do it, so could "beefed up" tranny gears. Any chance your tranny has been "beefed up". I know there are parts for the weak autos out there to do just that. They may whine, but haven't seen reports of that.

I'm no expert, just passing on what I've read on here. So others with more experience maybe able to answer you with more authority.

 

[94EddieBauerRock]

Thanks for the info doonze. My Grandpa owned the Explorer before me and I'm pretty sure he didn't over work it. I may have a couple times, but not too bad I wouldn't think. I've driven it about 2500 miles since the wine started and it seems to be operating just fine. We'll see how long it lasts like this.

 

[doonze]

I'd change my fluid and look for signs of burned fluid. If they start whining, there's a reason, you want to make sure that reason is no longer present. You don't want to grenade a tranny, back in my home town of Springfield, Mo there was a 15 year old kid who died because the Chevy truck he was working on grenaded the tranny. Was a big story and has always stuck with me. That's why I don't trust funky acting trannies....

 

[nitro71]

I'd swap the u-joints out. Can't hurt and could be the source of your noise.

 

[94EddieBauerRock]

Sorry to awaken an old thread but I thought I would post a video of the sound. I have barely driven this vehicle since the sound turned into a roar which is too bad because it is my baby. I don't want to go replacing stuff that doesn't need to be replaced so I figured I would post them on here and see if anyone has heard this sound before.
The sound occurs in all gears. For a while I thought it might be a pinion bearing or u-joints but now I am thinking it may be coming from the tranny/transfer case area. Anyone have any idea what this sound may be?

http://www.youtube.com/watch?v=Hs9WZhIDcXI

http://www.youtube.com/watch?v=a3UGKzkBIcc

 

[PatBennettAZ]

Any updates? See below please

Sorry to awaken an old thread but I thought I would post a video of the sound. I have barely driven this vehicle since the sound turned into a roar which is too bad because it is my baby. I don't want to go replacing stuff that doesn't need to be replaced so I figured I would post them on here and see if anyone has heard this sound before.
The sound occurs in all gears. For a while I thought it might be a pinion bearing or u-joints but now I am thinking it may be coming from the tranny/transfer case area. Anyone have any idea what this sound may be?

http://www.youtube.com/watch?v=Hs9WZhIDcXI

http://www.youtube.com/watch?v=a3UGKzkBIcc

I have a 1994 Ford Explorer that has a "new" catalytic converter and also had the modulator valve (I think that is what it is) replaced about a year ago. It has started "whining" when I drive and I am hoping someone has an idea of what to do. I can add transmission fluid, I had that problem before, could it be that again??

I hate to be like this - I am a female and well, sometimes I don't get the most honest answers - should I head to an AutoZone or someplace like that to see if they can run some kind of diagnostics first?

 

[Roadrunner777]

Welcome to the forums, Pat. LOL, it's a shame Arizona isn't abbreviated to AR. That would make your handle something very different.

Anyway, down to business. Check your transmission fluid level. The method is in your owners manual, and honestly, I forget if you do it in idle or park. I think it is stamped on the dipstick as well. If you need to add to it, you have to use Mercon V. Ford went through some issues back in the day and played with other formulas. This causes confusion with mechanics these days. I myself added the wrong fluid and things did not end well. Mercon V is the ticket, it's on the shelf at your local Walmart or wherever you get stuff. If you have to add fluid more than every year or two, you might have to look into where it is going.

Ok, all that said, tell us more about the modulator valve, what led up to you changing it. what else, if anything did they do? Flush the trans fluid perhaps? Filter?

Can you locate the sound? Low/old differential fluid can do this too, the noise would be more from the back of the truck.

Pull the transmission dip stick and describe what you see. Is it clean and pink or clear and nasty looking.

 

[blueovals]

Hello everyone. I just bought an 04 explorer xlt with a 4.0 and automatic. It just rolled over 148k on the way home from buying it. Everything seems normal for a 12 year old family vehicle. Except when I accelerate or go uphill and the tranny kicks down it lets out a high pitched whine. Not really loud but noticeable with windows up and ac on high. It will also slip a bit if I purposely kick it down and let off quickly. I'm new to these forums and not sure if this has been solved elsewhere but any help would be great. Im a diehard ford guy and fairly mechanically inclined. This is the first explorer I've bought because we now have 4 kids and the wife needed something bigger than her Taurus to haul them. Id hate to think I bought her something that will spend more time on the jack stands than the road so please point me in the right direction. Thanks again.

 

[natenkiki2004]

blueovals, you're better off posting a new thread in the right section;
http://www.explorerforum.com/forums...-2005-explorer-mountaineer-3rd-generation.93/
or the transmission section:
http://www.explorerforum.com/forums...orer-ranger-transmissions-transfer-cases.109/

But I'll still comment on your issue. The whine I wouldn't worry about so much as long as everything works fine. Many noises can be normal or not affect operation. Looking at vehicles, there's a lot done to them to reduce noise, vibration and harshness. None of which affect the product but rather they do it so people won't complain. The slipping issue though is something I'd think about. First and easy thing to do is to make sure the trans is full of the proper ATF. Maybe add an additional 1/2 quart for good measure. If there's no improvement then I'd exchange the fluid. Replacing the filter is up to you but if it were me, I'd stick an in-line filter on it and pump the fluid out through the cooling lines while filling with fresh ATF. Do that until clean and clear ATF runs out the cooling line.

 

[blueovals]

blueovals, you're better off posting a new thread in the right section;
http://www.explorerforum.com/forums...-2005-explorer-mountaineer-3rd-generation.93/
or the transmission section:
http://www.explorerforum.com/forums...orer-ranger-transmissions-transfer-cases.109/

But I'll still comment on your issue. The whine I wouldn't worry about so much as long as everything works fine. Many noises can be normal or not affect operation. Looking at vehicles, there's a lot done to them to reduce noise, vibration and harshness. None of which affect the product but rather they do it so people won't complain. The slipping issue though is something I'd think about. First and easy thing to do is to make sure the trans is full of the proper ATF. Maybe add an additional 1/2 quart for good measure. If there's no improvement then I'd exchange the fluid. Replacing the filter is up to you but if it were me, I'd stick an in-line filter on it and pump the fluid out through the cooling lines while filling with fresh ATF. Do that until clean and clear ATF runs out the cooling line.

thanks man. I gotta find some time to crawl under it to check tranny fluid. Kinda wish it had a dipstick lol

 

[Rhett]

thanks man. I gotta find some time to crawl under it to check tranny fluid. Kinda wish it had a dipstick lol

A 2004 Explorer doesn't have a tranny dipstick? If so, what a design.

 

[natenkiki2004]

A 2004 Explorer doesn't have a tranny dipstick? If so, what a design.

That surprised me too. Apparently it's a T30 plug you remove with the engine running. Fill it until it runs out like a diff or transfer case.

 

[94EddieBauerRock]

Wow. I just logged on here on a whim. I can't believe this old thread of mine got some action.
Unfortunately my Explorer has been rusting away in my driveway for 4 or 5 years now. It barely runs/drives anymore. Makes me really sad. As badly as I would like to restore it to it's former glory, I think it may be too far gone to save. I keep my eyes peeled for a rust free example just like it that I could bring back from a non rust belt state.

 

[Rhett]

Wow. I just logged on here on a whim. I can't believe this old thread of mine got some action.
Unfortunately my Explorer has been rusting away in my driveway for 4 or 5 years now. It barely runs/drives anymore. Makes me really sad. As badly as I would like to restore it to it's former glory, I think it may be too far gone to save. I keep my eyes peeled for a rust free example just like it that I could bring back from a non rust belt state.

I think you would be surprised what a little grinding, cleaning, and painting can do...I wouldn't write off your Explorer just yet. Besides, 94 Eddie Bauers are now getting rare.

 

[FirstExplorer]

Wow. I just logged on here on a whim. I can't believe this old thread of mine got some action.
Unfortunately my Explorer has been rusting away in my driveway for 4 or 5 years now. It barely runs/drives anymore. Makes me really sad. As badly as I would like to restore it to it's former glory, I think it may be too far gone to save. I keep my eyes peeled for a rust free example just like it that I could bring back from a non rust belt state.

You should have no problem finding a good runner. Unfortunately, you may have to cast your net out pretty far and have it shipped, but that could cost more than the truck. Many of these first gens got smashed and melted in Obozo's Cash For Clunkers.