Knocking after steering wobbling

[Emma2686]

Hello 👋🏻 I have a 2017 auto XC60. Last week I was driving usual route to work along dual carriageway. 10 miles into journey steering wheel started wobbling and then a loud knocking started which got worse with acceleration. Drove it to my local garage and noise had stopped when I got there. Mechanic checked car and couldn’t find anything wrong. Weekend driving was fine and then yesterday exact same route and it happened again steering wheel wobbly then the knocking started and this time louder. Drove back to garage and of course noise stopped when mechanic got in for test drive. Car hasn’t made the noise today but the ride doesn’t feel smooth almost like bumpy rumbling really hard to explain.
Any ideas 💡

[b1mcp]

Obviously it's a bit difficult without seeing/hearing/feeling the symptoms. But I'll take a guess that this is due to a failing Speed Sensor (there is one at each wheel).

If the problem was mechanical then it wouldn't go away. So very likely to be electrical issue. When a Speed Sensor begins to fail it can provide an erroneous signal to the cars systems. It fools the car into thinking that a wheel is spinning either faster or slower than the others. i.e. It thinks the car is skidding or losing traction. So it starts to use the Stability Control system and/or the ABS system to try and rectify it.

This can create knocking noises as power and/or brakes are applied and removed to the wheels.

In time it will get worse and eventually the car will work out that a sensor is bad and will set and store an error code, and provide a message on the dash which makes the diagnosis easy.

Before that, the way to diagnose if this is the case is to use a Diagnostic computer hooked up to the car while driving and look at the Live Data for the wheel sensors and try and spot if one of the signals looks a bit different to the others.