I need to replace the 1.2 8 valve engine on 2001 mk2. Are all of the 1242cc 8 valve units compatible for a straight swap.

I like a challenge but is it really worth it?

Mk2 has euro 3 and 4 engines
Mk2b had euro 4

There was slighlty changes as an extra cam sensor appeared....
Yes it would fit
But some parts would need swapping from what ive done in past

I dont know how well a panda / 500 / Gp engine would fit as im sure they also got changes too....

Also i found dropping engine and bpx was 10x easier vs getting just engine out


Ziggy

I think if you've got an engine with the squarish rubber pull off oil cap, then replace it with the same:
https://www.ebay.co.uk/itm/FIAT-PUNTO-MK2-ENGINE-1-2-8V-2001-2006-CODE-188A4000/163848466371

If you've got the engine with the round screw off oil cap, get one of those.

https://photos.app.goo.gl/TRca2JoMiyTKa8gR7

It’s the engine with the square filling cap. The only difference I can see is there are 4 bolts on my crank end top mount but appears to be 3 on the engine I’m looking at ?

There are a few more differences, the air filter, oil filter, spark plugs, cam belt, water pump, rocker cover are all different. Not sure about the clutch / gearbox mountings. I think the coil packs and inlet/injection stuff is different too.
I'm not saying a later engine wouldn't fit but to be on the safe side I'd recommend swapping like for like.
The later engine is the one used in the Grande Puntos.

Ithe replacement I’m looking at is out of a mk2b, there is a label on the engine with FOP on it. are the differences you mention for the later Grande Punto. As far as I can see the only physical difference looks to be the right hand engine mount casting, did this change on the mk2b

The existing engine has DOB on the label

I think the coils are different and possibly the fuel injection as the air filter is different, due to these there may be some more mounting differences. Mine is a MK2B engine and has FOR on the side and mine is a really late MK2B as it was sold after the GP was introduced (April 06).