Rattling noise "only over 60 mph"

[Monalis]

The other day Betty started making a racket, sounds like the radio console is loose or something is in the glove box rubbing against the plastic. (hope you know what I'm talking about)


Over the last couple of days I've tried to figure out what is causeing the noise and have yet to figure it out. So here are my observations in hopes someone has had the same problem, or something similar and can help me figure it out.

• The noise starts exactly when I hit 60 mph and stops as soon as I dip below 60.
• There seems to be nothing loose, at least pushing the differant "panels" doesn't cause the noise to stop.
• Taking everything out of the glove box does not help
• Turning off the AC doesn't help
• Took all the CDs out of the player, didn't help.
• It seems that at night the noise isn't there, but I'll have to pay closer attention tonight.

Betty is just over a month old, and has about 3,000 miles on her. It's been really hot durning the day, upper 90's to low 100's and a bit cooler at night, in the 80's.

So I wonder what part of my car could be making this noise only when it is really hot out and only when going above 60mph.

Please help, it is driving hubby crazy (when I let him drive)

[John_H]

It's possible one of the balance weights on a wheel came off and what you hear is the resonance coming from part of the screwed-together assembly.

Since it's only a month old, if the weight came off there should still be evidence it ws there. Take a look at your tires to see if there's anything that looks like the footprint of a missing weight. You should have weights on the wheels - almost never is a wheel balanced with no adjustment.

It's a bit extreme to need your wheels balanced when it's only a month old, but perhaps your Smart Center would take care of that for you (if you ask nicely) if you're up that direction anyway. Maybe you need an excuse to purchase Smart branded goodies!

[jetfuel]

...so..what happens after 60...louder?
...does your car bounces up/down at 60?
...does your car shimmy left/right at 60?
...is your "hood" properly engaged in the upper tracks of the body?
...what's for dinner?

jetfuel

[slk230]

My cabrio also "developed" a rattle. Turned out it was the passenger seat belt banging against the plastic. I just grab it and pull it out to place the metal portion on the seat and the rattle goes away.

[Monalis]

Originally Posted by jetfuel

...so..what happens after 60...louder?
...does your car bounces up/down at 60?
...does your car shimmy left/right at 60?
...is your "hood" properly engaged in the upper tracks of the body?
...what's for dinner?

jetfuel

It stays the same up to about 75, haven't gone over that yet, as soon as I go below 60 it stops, just to start again as I hit 60.

Car doesn't have any additional movement, no bounces or pulling to the left or right, that I can tell. I'll pay closer attention on my way home to check alignment on the road.

Hood is properly engaged and latched

And I think it's apple & sage grilled pork chops, around 9pm central.

[jetfuel]

...open the door and check the "flaps"(3ea) that secures the front fender to the inner body... see if they are loose....don't just trust your eyes...see if they can be moved with hand pressure...
....pasta primavera on this end...

jetfuel

[Monalis]

Originally Posted by John_H

It's possible one of the balance weights on a wheel came off and what you hear is the resonance coming from part of the screwed-together assembly.

I never even thought about the weights. But since it doesn't drift, that I'm aware of, I don't think its that. But I'll keep it in mind and check for drift on my way home tonight.

Originally Posted by slk230

My cabrio also "developed" a rattle. Turned out it was the passenger seat belt banging against the plastic. I just grab it and pull it out to place the metal portion on the seat and the rattle goes away.

I wish it was that easy, but since both hubby and myself were in the car this weekend and still heard it. I don't think its the seat belt. But I will keep that in mind since I usually do drive alone.

Originally Posted by jetfuel

...open the door and check the "flaps"(3ea) that secures the front fender to the inner body... see if they are loose....don't just trust your eyes...see if they can be moved with hand pressure...
....pasta primavera on this end...

jetfuel

I'll check those in a bit, when things slow down over here. I hope it's something simple.
.... mmmmm pasta

[jetfuel]

..one more ...open the hood...make hubby check the fan housing...big black round coffe can looking thing on the passanger side of the car...again..see if it will move when hand pressure is applied...high speed/frequency vibration noises will drive anybody up a wall....

jetfuel

[NeWave]

I've got a similar issue, but I'd call it more of a tapping for me. Anything above 45 and it starts tapping right near the drivers door.. somethings loose. Just don't know what... Good luck on figuring that out.
Grilled Cod with seasoned rice...

[John_H]

Originally Posted by Monalis

I never even thought about the weights. But since it doesn't drift, that I'm aware of, I don't think its that. But I'll keep it in mind and check for drift on my way home tonight.

A wheel balance problem typically results in vibration, not drifting. Alignment problems - a separate issue - are what cause the car to drift.

To make sure it has to do with tire speed rather than engine RPM between 60 and 75, try changing gears to 4th gear (which is still below redline at the electronically limited 92mph). You can even check 3rd gear at 60mph though I didn't like holding my car at 65mph in 3rd gear up those hot California mountains coming over from Oregon; it'll do it, though. Your engine will automatically upshift if it's at redline so you can't blow your engine by kicking it into 3rd. I just don't like the noise.