Revs are really high but it doesn’t feel like its getting any power, then it jolts and gets power, much worse up hill.

Transmission fluid isn’t gritty, and it’s a light red, it’s in the middle of the min/max, haven't noticed any leaks. 

It’s a CVT gearbox. Only happens in drive. And literally just started yesterday when I was halfway home from work.

It’s never given me any problems before, apart from the throttle cable which is on its last legs.

Taking it to the garage on Monday but does anyone have any ideas on what I can expect they’ll say. I assume it’s very bad news.

Some extra information: it's got 45,000 miles, 1.1 petrol, just had it's MOT like two weeks ago.

I doubt many garages will know how to fix a CVT box tbh, they'll probably tell you to either source another for replacement or send you to a transmission specialist.

You say it only happens in drive - so can you reverse uphill without the slipping and jolting?  Replacing the fluid and filter would be worth a try even if it looks ok, it's going to be the cheapest option.  Next thing to try would be the torque converter imo. 

Thanks for the reply!

Reversing is fine, feels as normal even up hill, is that worth noting? 

Luckily theres an Auto transmission specialist pretty close, because I've no clue where to find the replacement, if it does need one. 

2 hours ago, sworp said:

Reversing is fine, feels as normal even up hill, is that worth noting?

Yeah, reverse on a CVT uses the same band and drums as drive so that helps us rule out quite a few major parts!  I reckon it's the drive clutch that's worn out which will require the box to be removed and disassembled for replacement parts unfortunately.  I'm by no means a CVT expert though!

Thought I'd let you know I went to the a transmission specialist today, he said that the front drum has stuffed it. Too expensive for me to repair, so R.I.P little fiesta. 

22 minutes ago, sworp said:

Thought I'd let you know I went to the a transmission specialist today, he said that the front drum has stuffed it. Too expensive for me to repair, so R.I.P little fiesta. 

Glad you've got a quick diagnosis, just a shame it's not a good one.