Sign of a bad gearbox (only use genuine PSA oil ffs!) -
Turbo exhaust oil seal blown - couldn't confirm cause
Failed clutch release bearing -
Damaged clutch and DMF - overheated (slippy clutch and too much power lol)
Snapped cat - Peugeot quality
Snapped spring (see...tapered springs are dangerous!)
Thermostat stuck open - GM quality
Burnt connection - loose fit leading to arcing
Fuel pump leak - damaged seal caused by running veg oil
Burnt fuel pump pin - caused by Peugeot electrics
Gearbox scored by stray rivet stuck from clutch cover (I think)
Got a bit carried away looking at broken things on photobucket...

I know they're not all engine related, but hopefully some are of use.