I recently bought a Ford Fiesta 1.4 as a little runaround. It came with 3 buckled alloys - yay (not!). I had 4 new alloys put on it and had it balance but now it has a rhythmic shaking over 60mph (or at least that’s when I can feel it). It feels like the steering wheel shakes for 2 seconds then the chair for 2 seconds then back to the steering wheel. It is very rhythmic and does not go away.

It also runs rough when cold - was told head gasket then not head gasket then vac pipe then not vac pipe. Mechanic hasn’t a clue what this could be and suggested a software update? Sparks, coil pack/leads have been replaced

Any ideas?

34 minutes ago, KV331338 said:

It feels like the steering wheel shakes for 2 seconds then the chair for 2 seconds then back to the steering wheel. It is very rhythmic and does not go away.

Worn and/or damaged wheel bearing(s) after driving around with buckled alloys. Usually a cheap and easy job to have them replaced.

19 hours ago, KV331338 said:

It came with 3 buckled alloys - yay (not!). I had 4 new alloys put on it and had it balance but now it has a rhythmic shaking over 60mph (or at least that’s when I can feel it). It feels like the steering wheel shakes for 2 seconds then the chair for 2 seconds then back to the steering wheel. It is very rhythmic and does not go away.

'New' alloys?  What does this actually mean?  One or more of your 'new' alloys is also bent.  What tyres are on the wheels?  (Worn bearings will not make the car shake at certain speeds.)