Mine has a big blue plastic pin that seems to just keep the pedal in the right place. Ive examined other units and cant see it tho... 

I shall attempt to get pictures, but is this pin normal. Its just casually pushed in the side loosley. Its not held in by anything.

There is a big blue switch above the pedal.  I can't think anything else blue in that area.

2 hours ago, TomsFocus said:

There is a big blue switch above the pedal.  I can't think anything else blue in that area.

That is whats bothering me. I dont know why its there. Its just in the left side of the pedal in a hole near the top. It doesnt connect to anything, isnt secured to anything, and just seems to be propping the pedal slightly upwards of its 'normal' resting position. I will take it out and go for a short test run, see if it makes a difference. I will upload pictures here of it in situe and removed but it does just appear to be rather odd and not needed.

https://www.ebay.co.uk/p/1709803018

Its one if those, randomly stuck in a hole in the aide of my brake pedal. WTF. At least I know it shouldn't be there.

https://www.onbuy.com/gb/p/ford-fiesta-mk7-accelerator-pedal-pin-bush-4983703-9l34-2l523-aa-new-genuine~p68517726/

 

But the diagram on that page, despite it saying accelerator pin bush, shows it being where it says it goes on the brake pedal. Im confused.

10 hours ago, SquidgyB7421 said:

https://www.onbuy.com/gb/p/ford-fiesta-mk7-accelerator-pedal-pin-bush-4983703-9l34-2l523-aa-new-genuine~p68517726/

 

But the diagram on that page, despite it saying accelerator pin bush, shows it being where it says it goes on the brake pedal. Im confused.

Ah, I see what it is now.  Thought that part was white, not sure I've ever seen one in daylight.  

It should go through the brake pedal, holding the pedal to the master cylinder.  There's like a 2 pronged fork on the master cylinder that goes around the pedal.  That's why it's not shown on any breakers yard pictures because it has to be removed before the pedal assy can be removed.  If you try to pull the pedal outwards, it should not be possible if that pin is in the correct place.

 

You can see that clip clearly on this video.  From around 45 seconds in.

But why is it just loosely in there? Id have thought it would be secured somehow.

14 minutes ago, SquidgyB7421 said:

But why is it just loosely in there? Id have thought it would be secured somehow.

All the force is lateral.  There shouldn't be any force pushing it lengthways.  There are a couple of small one-way tabs built into the plastic to prevent it vibrating out.

I just wana know whats sending a vibration through it at 65 - 70. Theres no other symptoms of anything. Keep investigating I guess.