convertible owners: what helps cowl shake?

[briandors]

95 Cutlass Convertible.

 

I have a lot of cowl shake when I hit a bump, at just about any speed. I also have a cowl oscillation around 40-50mph. These cars already have a strut tower brace, would adding a second one (if it'd fit) help? Do you think the 40-50mph shake is a bad wheel (a couple have large weights on them, they have been balanced and that helped a little) or am I just hitting a frequency in body vibration where the car is naturally wanting to oscillate? Struts are new all around.

 

Brian

[LukeZ34]

Mine seemed to do that as well. You could try having your wheels balanced, but it may just be the nature of the convertible frame.

[jeremy]

Mine seemed to do that as well. You could try having your wheels balanced, but it may just be the nature of the convertible frame.

 

something is wrong with it....whether it is the rims or the suspension...a convertible shouldn't drive any different......

[briandors]

convertibles in general have cowl shake, every mag writes about it. i have driven a sebring and a mustang drop-top and both of them had shake when you'd hit a bump.

what's different with my cutty is a back and forth motion that happens continually at a certain speed. wheels have been balanced, so either they're really bent, or the frame is kind noodle like on this car.

 

i'd hate to spend money on new wheels to have the shake continue, so i'm hoping other convertible owners chime in. thanks.

[GnatGoSplat]

I have not really noticed cowl shake on mine, but my 88 and 89 coupes have terrible dash shake (feel like it's going to fall in my lap) so if the 94 convertible has cowl shake, I just may not have noticed it.

 

If other convertibles have this problem, it might not be something that can be fixed without getting creative with extra bracing here and there.

[topless94style]

What is cowl shake? Maybe i can tell you if i have it or not.

[briandors]

it's this left and right, shaking motion. you're most likely to notice it if you're staring at the rearview mirror, because the whole windshield is shaking left and right, back and forth. to some degree so is the dashboard.

 

brian

[WhiteOut]

Cowl shake in normal, lots of it while driving down a road is not. Something in your suspension has to be worn out. The only time I get really noticable shake in my car is when hitting potholes or on bumpy surfaces (dirt roads). And when it happens boy does it ever happen, if you watch the gap between the floor console and the dash the dash will have about 2" of play while it sways back and forth. Kind of scary. If its only happening at a certain RPM I'd suggest having your suspension checked out each part has its own ocillating frequency but that should all be damped out if things are working normally. So something has got to be worn or broken.

[jpv123]

I haven't noticed it on mine. I've had other convertibles, but they all seem to flex a bit but not where it's a concern.

[Mike]

All Convertibles suffer from some sort of cowl shake. Think of a coupe as a shoe box with the lid on. Apply a torque(twisting motion) and the ends of a shoe box with the lid on and notice that it resists the motion. Now take the lid off(a convertible) and do the same thing, you can see that it is not a strong as before. Therefore, if a car was originally a coupe and then made into a vert, it will not be as strong as the coupe as it was not properly designed to function without a the lid (bracing can only do so much)