I've had this problem for god know how long. Never thought anything of it either.

I get a very Low Frequency vibration around 30mph. And it's always the same. If I cruise at just the right speed it's very loud and noticeable. Nothing is wrong with the car. Engine Mounts are good (they were checked in July).

Any of you guys have a similiar problem?

 

warped rotors?

 

Nope, because in the past after having a brake job completed the vibration would still be there. I'm due for another brake job on my next service I'll check it again to see, but I doubt it.

 

My 6spd does something similar at like 3k rpms on the highway...

I think it's normal to get more vibration (NVH - Noise, Vibration, Harshness) out of a manual transmission car than a automatic...

Maybe it's the tires out of balance, needing air, or maybe you've just discovered the natural harmonic frequency of a 03 6spd

 

I know it's not the tires because it's been there before and after I got new tires put on the cars.

But you're right it may just be normal.

 

Does it happen when the sunroof is open? Many people have complained about the wind deflector vibrating at that speed and making that noise.

 

Happens when it's open or closed.

 

Check you tires. Are they cupped?

Cupped tires will lead to a "tornado, vibration" sound...

 

Is it rpm related or speed related? If you raise your rpms to around 1000-1200 or higher in park do you notice a buzzing or vibration? I had a vibrating alternator pulley tensioner that caused a buzzing and slight vibration.

 

Has nothing to do with Tires because the noise has occurred with 3 different sets of tires.

 

Well for one thing I don't have a lazy stick, so "park" has no relavance.

In addition, It doesn't happen when I'm at idle, it happens when i'm moving. I haven't tried it in different gears, so I'll do that. Thanx for the suggesstion.

 

THEN, Try my suggestion in neutral . Mine did not vibrate at idle in park but did when I raised the rpms in park.

 

IF the problem in my car is the tranny, then it would share no similarity with yours though because I've got a 6spd.

I'll give it a try though.

 

bent axles--that's what my car was doing. If it does it on acceleration and deceleration at the same speed, it's the axles. Sorry

 

That's a possibility; however, this past July I just had something that had to do with my axles repaired. I just can't recall for the life of me if I had the axles replaced or something else. I gotta check my invoices.

I have a feeling though it's not that because it's done from way back in the day when I had low mileage on it.

 

I get a simlar vibration at 1200-1500 RPM in any gear & in N. Mines RPM related not speed. Both my 6 speeds did it at the same RPM.

 

I just thought of something, If it were the axles I should be able to feel the vibration in the steering wheel. That's what originally alerted me to the problem I had back in July.

This vibration has been going on for sooooo long that I seriously doubt it's the axles because for one thing there is no vibration at all in the steering wheel. And second, the vibration is at such a low frequency, the whole car literally shakes and sounds more like there's a 15" sub in the trunk going nuts.

 

Did we establish if this was RPM or speed related yet?

Just and idea but when you notice it, depress the clutch pedal and coast. Does it still do it when the car is at speed, yet not under power?

Also, when you say "sounds more like there's a 15" sub in the trunk going nuts", where is the sound originating from? Front or rear of the car?

I would be willing to bet something in the suspension is slightly bent. A buddy of mine had a Jeep (I know, completely different) but he had one little piece that was bent and when he drove it in town, you'd never notice it. Once he got it on the highway and up to speed, it was awful. Vibrations, noise, etc.

My $.02

 

Thanx for the

I'll try it under neutral too and see what it does. I'm gonna try it tomorrow morning (being the weekend) so I have time to fiddle daddle with it and try to narrow the factor's down to isolate the problem.

 

Update -

Well I tried a few things.

I tried driving the car in different gears at the speed that the vibration occurs, and the vibration was still there, so RPM's are irrelevant.

This is further supported by the fact that I threw it in neutral at this speed and the vibratino was still there.

Since it the vibration does occur even when the car is in neutral it can't be the engine or tranny. My guess is that it's something on the wheel.

I'm due for a brake job very soon. IF it is in fact the rotor's we'll find out then. I doubt it's the tires because like I said, I've gone through 3 sets of tires and the vibration was still there during that time.

The only thing that makes sense is that it's either the rotor's or possibly the axles. But I doubt it's the axles because I did have some work done on those not too long ago.

 

Good luck with it. Keep us posted on what it was.

 

i say its bad inner axle joints, my car does it too, from about 45-60mph, there is no vibration in the wheel, the tires are perfect and balanced. everything else has been ruled out, its got to be the inner joints. when mine does it i can feel the vibration in the floorbords the most. i think they tend to go bad on these cars to much because of the tremendous amounts of torque that is getting passed through them. i talked to the people of www.raxles.com and they have axles with new joints and are cheap compared to the oem ones that still have the same problem, give them and call and see if they have figured out why they are going bad.

 

Looks like the problem is now solved.

About 2 weeks ago I replaced the rotors on my car. Earlier in the thread I stated that after having the original rotors resurfaced that the vibration was still there. Hence why I didn't think it was the rotors. guess they were the culprit. I guess resurfacing the rotors didn't do enough to make the rotors balanced again causing the vibration.

So far I haven't had any low freq. vibration issues since the new Brembo Blanks were installed. But I'm still keeping my fingers crossed

If the problem comes back I'll be sure to post up again.