Crunching / crushing sound over speed bumps


I have a ford ka+ 2018, owned it for a week and noticed when I’m driving over speed bumps there’s a strange sound from the front left of the car.

I have googled the issue and applied Wd40 specialist silicone spray to the control arm bushes and took it out for a test drive and it’s still the same.

I’m not very knowledgeable about cars and spraying lubricant on the bushes is something I’ve never done before, I’m concerned if I’ve done the right thing? Surely it won’t hurt and help the bushes even if the actual issue isn’t them?

So I still have the noise, is it due to the cold weather ? I mean the car has only done 10k and looks pretty new underneath.

Any help would be great, thanks

Faulty valving in a strut/shock can make that kind of noise.


Since you don’t know much about cars, I’d have a mechanic take a look. It is a bit surprising for a car this new.

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A mis-aligned strut dust-cover can also make that noise, especially when it is cold outside. It is annoying but not critical.

The dust cover, or more correctly, bellows, is inside the front spring and surrounds the strut’s chrome plated rod to protect it from debris. It is the black ribbed part under the white part.


Welcome to the community. The silicone spray won’t hurt the bushings, so I wouldn’t worry too much there. The sound is going to be hard to determine what it is exactly without hearing it first hand. Obviously it’s most likely something in the suspension- shocks, bushings, etc. If it makes the sound when you push down on the bumper and bounce the suspension, you might have a friend help you isolate exactly where the noise is coming from.

what type of sound is it? squeak, bang, rattle? if you can post a clip of the sound it might help.
but since you do not know much about vehicles or how to fix them, you need to bring it to a reliable mechanic. if you do not know one then ask your friends or neighbors if they know one.