Loud humming noise @ 40-50mph

[rsboy]

Need help on diagnosing this noise on my 98 DX.

When driving normally, I get a metallic humming noise at around 40-45mph. The noise goes when I press down on the gas and the speed goes up, but as soon as I hit around 45mph, under 50mph, the noise comes back. Any suggestions on what it could be?

I'm using the stock steelies and I haven't really checked the condition of the rotors or brake pads since I bought it, but brake still feels ok. Will change rotors and pads pretty soon. But they don't make noise when I use the brakes, etc. So i'm thinking it might be something else.

Just background info... the car has 88K+ miles, stock suspension(still good, rebound and stuff is good), stock steelies with a/s tires, stock clutch, haven't changed timing belt and stuff but generally in good running condition. Most of the general maintenance on it has been done since I bought it, but still a work in progress.

Could it be the wheel bearings? Belts? Pads/rotors? It loud enough that I can hear it over the radio and seems to be louder with the A/C on at setting 2 at the least. i can still hear it with the A/C off so that's why I'm stumped. I thought it was a belt that was slipping or something.

any help would be appreciated.

 

[trace01m]

That's odd. Maybe something to do with the tranny/diff. Check your fluid levels

 

[Raabe]

i actually had a really loud grinding noise in my 99 DX and i couldt figure it out. It sounded like somthing was grinding in th eengine itself but at a stop i coundt hear it....it was actaully the plastic skid plate piece that covered my fron driver side wheel, and it had come unatttached from my front bumper, and the noise was the metal washer-like piece vibrating..lol, check that

 

[1337 | RCE]

I've had a bad rear wheel bearing and I don't remember it being real loud. could drown out the sound really easy. unfortunetly that's the only help i can provide. good luck finding it.

 

[Matt.]

Do you have any audio equiptment? get your alternator tested

 

[Suanico]

tires?

 

[hardcore97]

I've had a bad rear wheel bearing and I don't remember it being real loud. could drown out the sound really easy. unfortunetly that's the only help i can provide. good luck finding it.

my buddy had one go bad on his focus and that thing was loud. he had a cat back exhaust that was pretty loud and going down the interstate you could hear the noise from the bearing over the exhaust

 

[rsboy]

I replace the tranny fluid with Pennzoil Syncromesh, and it drives fine normally. The tires could be agood possibility, BUT the sound happens at cruising speed between 45-50MPH. I go below it or about that speed...no sound. But as soon as I hit the 45mph mark, it comes on and I'm not pressing hard on the gas.

No audio equipment. Stock speakers with a none stock headunit, but no big power stop. I will get the alternator checked though. Wouldn't hurt to check since it had 86K miles before buying it.

Anyone know how to check a bad wheel bearing? I turned the wheels when i had it up in the air and both front wheels didn't have any major slack on it. Wouldn't a bad bearing make noise at any speed though?

It seems the noise is coming from the front driver side area... i'm assuming since I think it's in that direction. I look around the wheel well area and all that stuff again, but more help would be great.

thanks for the replies so far!