The garage doing my suspension and brakes took out the front roll bar thinking it was being replaced rather than a RARB being fitted. They replaced a couple of bushes on the front roll bar. Took the car for a spin and whilst the suspension and brakes feel fine the engine note has totally changed sounds like a bag of nails or like something is rubbing against something else. Before going in for the work the engine was quiet and smooth now it sounds harsh like there was no oil in the engine. There is no noticeable change in performance. Any ideas as to what might have caused this? Is there any way the timing could have been affected? Am looking for suggestions as I am at a total loss.Thanks.

I suspect you now have an exhaust leak courtesy of your garage.

Or could the downpipe now be touching the FARB?

Turns out it was a loose bracket, I presume an exhaust bracket, thank you both for your suggestions.