"New" Engine concern

Okay, so few weeks ago my 2020 St edition has had a new engine covered under warranty(thank fuck) due to piston slap on cylinder 1 but I'm still a tad concerned with this "new" engine. Its had about 1300 miles on it since fitting and never thrashed it, always Waiting for the engine to slightly warm on cold starts and my daily commute is just me sitting at approx 2.5k rpm on the carriage way but this engine just sounds awful at times when I do put my foot down a little... And mostly under load like up hills, do these Dragon engines just sound terrible mechanically even brand new?

When you say it sounds awful are you referring to potential metal on metal contact, misfire, burning fluids, or just the exhaust note?
Different fuel injection styles will have different sounds under the engine bay.
If the car is running fine and does not present any issues I would imagine it is just the exhaust note you are worried about.

Do ALL of the Mk8 engines used now have dual injection (port AND direct)??

Maybe it is the sum total of all of those injector 'ticks' IDecX is hearing?

Is this a naturally aspirated 1.5 3 pot, or are they using the old SFE's (and base power plant for the Rally 4 cars) 1.0 3 banger EcoBoost in that ST Edition (which I am guessing is the equivalent to our Mk7(.5) 'ST LINE' Fiestas here)?

The Dragon engine is the 1.5L EcoBoost found in the Mk8 ST variant.
https://www.ford.co.uk/content/dam/...s/component-sales/1.5l-dragon-gtdi-engine.pdf

I have no experience with it, but have heard both this and the Corolla/Yaris 1.5L 3 cylinder have terrible exhaust notes from factory. And when you mention it sounding bad when flooring it up hills you might just be lugging the engine. Easily noticed by deep burbling strained engine sounds. Try switching down a gear and get some revs up. Even with a small turbo it's happier above 3k RPM when you floor it.

Sorry for long reply, I completely forgot, It sounds metallic and very similar to the sounds I was getting before the engine got replaced, engine feels smooth and accelerates smooth but I'm still not sure. It could just be loud lifters or the injectors like the the 1L ecoboost they're known to have very loud injectors as my dad's 19 , 21 and even his new 23 plate st line have very audible injectors. My noise is mostly heard under a heavy load like going up a steep hill and I know the exhaust note is weird as it's a 3 cylinder but it's not that

I'm hoping it's the loud injectors as the engine still feels smooth as silk while accelerating while my last engine had a loud knocking sound and felt rough. This is the turbo charged 1.5l St engine 200ps

So they offered an actual Fiesta ST 'Special Edition' before the current/last model year of the Mk8 Fiesta ST (the one you can get in the Focus RS's shocking/Nitrous Blue color)?
Somehow I thought that was only ever offered/released for the 2023-2024 model years, and not in 2020.

That's why I was questioning which engine you had, since I thought you owned something like our (aesthetics/body kit only, NOT an actual ST) Mk7(.5) 'ST LINE' car, which I guess you never had over there?

yeah i have the 2020-2021 ST Edtion the bright blue one very similair to the Focus RS nitrous blue,its called azure blue apparently, The engine feels smooth so im hopeing that noise im hearing its just loud af injectors

The Mk7.5 had a physical sound symposer hooked to the cabin to enhance the induction noise. The Mk8 apparently has some acoustic enhancements in forms of digital sound.
It might be fake induction noise pumped through your speakers. It is removable though. But if it's mechanical sounds like ticking it might be injectors as mentioned.
https://www.fiestastoc.com/threads/virtual-exhaust-cabin-sound-again.325137/#post-4558069

Are you sure they replaced it? Maybe they repaired the existing one by servicing only the first cylinder.

Down with the POSER noises LoL. At least put an off switch on that nonsense.

No it's been replaced, the block and head is brand new shiny while my alternator and other auxiliary's are dirty and obviously older which must have been taken off the old engine and it on this

You could always take it back to the dealer and ask them to look into the issue? Perhaps there was an installation issue. Or you could compare to someone else's car?

A number of years back I had a Mazda RX-8 that seized while under warranty. The dealership put in a new remanufactured engine, but reused the old $7 oil filter with metal shavings inside (I checked!) because the manufacturer didn't include it as part of the authorized replacement parts. Dealerships don't always made good decisions.

Hello again, it's been a little while but here's a update, new engine is on approx 2800 miles now, the noise in question hasn't gotten much louder but is louder non the less and it's seeming to last longer too, I'm wondering if it has the same issue as my previous engine but I'm not sure on what's caused or causing it, I've not thrashed it, I always wait for the engine to warm a little before pulling off on cold starts and I only ever put my foot down when I know the engine has fully warmed up so why am I being punished for looking after a engine how it's supposed to? I like the car and want to keep it when it's finance is payed off but I don't know anymore it's pissing me off, it took 6-7 months to get through to ford to finally replace the last engine I really don't want that fucking nightmare again

Ah no the GR Yaris and Corolla gave actually a really cool sounding exhaust note from the factory and Bob the guy I sold my FiST too who is on here can attest to that as well as he has heard my GR’s exhaust note.😜

edit.. I should add when I saw all the tests for the MK8 it sounded pretty damn cool as well . 3 cylinders for some reason sound more like their 6 cylinder brethren than a 4 cylinder and invariably can have a cooler exhaust not than the 4.

No problem with my exhaust note I like it, it's not the bog standard 4 cylinder noise you hear everyday, but any answers on what to do next will be appreciated. Bite the bullet and pay £4k for a forged rebuild or try crawl my way through the 1 year part warranty I have on this engine and try get a new one(Ford will not be happy imo)