Does anyone know if the 4-cyl, 2.2L Ecotec engine in my '04 Ion is an interference engine? (ie: pistons can hit valves)

 

It is an interference engine and that info can be found in a 30 second internet search. For alot of information try searching the internet using one word.

ECOtec

 

and then you can add a second word like.

ecotec family
ecotec engine
ecotec specs
ecotec performance
ecotec parts
ecotec supercharger
ecotec turbo
ecotec 2.0L
ecotec 2.2L
ecotec 2.4L
ecotec Saturn
ecotec ION
ecotec SKY
ecotec VUE

and the list goes on and on for ecotec searches.