Hi I have a 2007 1.2 fiesta looking at best way to engine upgrade or is it better just to put something like a 1.7 puma engine in it but where do I stand with wiring compatibility thanks. But before I start fan doesn't kick in so temporarily fitted switch inside car any suggestions what to try, I have looked at fuses and relays but seem ok 

Cheers

Your best bet is to find another car that has the performance you are looking for. It will be cheaper to insure than a modified car. Swapping engines is not as easy as it was back in my day (1960's & 70's), due to all the electronics.

As regards the fan, does it work if you short out the wires to the temperature sensor (probably on the radiator)? If so, then the sensor probably needs renewing.

Unfortunately there are no "quick wins" with a small normally aspirated engine as you get with a remap on a turbo.

You might get 8 bhp or so from a remap and a filter, but any more would require very serious work (a member in this thread got to over 100 bhp by doing so):

https://www.fordownersclub.com/forums/topic/14568-fiesta-125-tuningperformance/#comments

Similarly with engine swaps - you can do almost anything with the right skills and resources if you are equipped to undertake such a project - I've seen an Up with the drivetrain from an Audi TT Quattro on a VW forum!

Realistically though, as Alan comments, a car upgrade is the logical route. It's hard to recommend an early Ecoboost unless you can absolutely guarantee the belts have been changed correctly. A Mk 7 Zetec S though, for example, would give you near 120 hp and importantly the suspension and brakes to go with it.

 

Well guys ( @Alan G H & @Eric Bloodaxe ) you both failed miserably with those sensible answers. 🤔

Phil has been back and had a read, and clearly wasn't impressed. 🙁

On car SOS they regularly just drop an Aston Martin V12 in a Fiesta with absolutely no problems 😂

Build up some NCB then buy a MK7 ST

16 hours ago, unofix said:

Well guys ( @Alan G H & @Eric Bloodaxe ) you both failed miserably with those sensible answers. 🤔

You can now add @DaveT70 to that!😀

😄

Well thanks for your ideas so looks like I've got a scrap fiesta on the driveway haha 

On 5/29/2025 at 9:01 PM, Alan G H said:

Your best bet is to find another car that has the performance you are looking for. It will be cheaper to insure than a modified car. Swapping engines is not as easy as it was back in my day (1960's & 70's), due to all the electronics.

As regards the fan, does it work if you short out the wires to the temperature sensor (probably on the radiator)? If so, then the sensor probably needs renewing.

Yes fan works if I give them a direct feed, sensor been replaced so looking at relay but not sure which is correct if you have any ideas or wiring diagram would be great cheers

11 hours ago, Philford said:

Well thanks for your ideas so looks like I've got a scrap fiesta on the driveway haha 

Can you not find a used engine of the same type, assuming the rest of the car is in good condition?

Having said that, a 2007 Fiesta is probably not worth enough to justify the expense. 

Surely the fan issue would be there on the transplant completion?

Can you not just fix the fan issue?