My 2007 A4 2.0 petrol (non Turbo) uses about 1lt oil per 1000km. it has 178544km on the clock. is this oil usage correct or excessive. there is no oil leak and the car does notg smoke.
I use Shell Helix Ultra.

 

I've never seen a car that did not use a little oil. Anyone who says their car doesn't burn a drop is full of crap. Your oil consumption isn't anything to worry about. You just need to keep an eye on it like you apparently already do. Like you said, it's not leaking and it's not smoking, you're fine.

 

I removed the coil packs to change the spark plugs last night and they had a lot of oil on them, it looks like the oil is leaking into the holes that the coil packs fit into.
could it be the gasket that needs to be replaced?

 

Sounds like it to me.. If you have any oil down in the spark plug tubes, it has to be coming from the valve cover gaskets. There's an outer edge gasket and 4 separate ones that you have to tap out and tap back into the holes for the plugs. Also be sure to properly torque all of the bolts to the proper spec (the number escapes me at the moment). Torque them from the center working your way out to the ends in a criss-cross pattern. Let it sit a few minutes and check them all again.