Symptoms of a broken Coil Spring
Car is leaning
The coil springs support the weight of your car, from each corner. If one of them breaks, your car won’t be supported in that corner. So, if you spot your car leaning - to one side, or to one corner - then you may have some busted coil springs.
Car is sitting too low
If the coil springs are failing, you may notice less of a lean and more of the car just being way too low. It will look funny, that is, if you’re perceptive enough to notice the difference.
The coil springs hold your car up. If they’re not doing their job, they won’t hold your car up. Just imagine yourself without calves. That’s your car with faulty coil springs. Not so fun, huh?
Knocking noise
Please tell me this isn’t new information to you, but your car shouldn’t make bizarre noises. If it does make bizarre noises, it’s usually because something is wrong, and that something should be fixed.
If your car has some busted coil springs, then it will likely make a knocking noise. You’ll notice this noise coming from the suspension when you drive over bumps, or other imperfections in the road. It’s the sound of malfunctioning coil springs being forced into action and failing.
When in doubt, listen to your car.