Hi all , my daily driver has just started acting up and i am totally stumped.

Took my egr valve off my 2010 tdci astra estate , gave it a good clean and now my car wont start.
Its turns over but its a different noise when turning the key (sounds well different can tell somethings not right so turn it off straight away)and wont fire up then when i remove the key the egr valve is clicking plus a humming noise.(might not be related to it not starting)
I have re done everything A million times checked wires etc spent 8 hours yesterday on it and have just fully charged the battery.still nowt.
I am worried the black carbon soot has fell into the engine ( some one please say this isnt poss! lol )
Anyway i have to get my kids to school tomoz so all help is super appreciated cheers.