2003 a6 3.0 quattro :mad. this is the 2nd time ive had this issue with my car. both times it was very cold and will not start. all electric works, but the car will make no attempt to start. wont even turn over. First time it happend the vehicle sat for a couple days and then went to move it and said ill try and start it up one more time and boom(fired right up). cept check engine light came on. checked codes and had random misfires in 3 diff cylinders. had all 6 ignition coils replaced along with spark pluggs/wires, starter. Also had the oil changed and power steering system flushed. Basically serviced and checked vehicle over.
2nd occurance same issue wont start, and is cold. Car was running beautiful since had all that work done. Only issue was coolant light would come on every other day. coolant level in resivour wsas getting low every 3 days. so i have a leak. thought it was cracked resivour because when i released pressure it would pour out of the bottom. Until i took it apart and realized it has an overflow hole in the top next to the cap. dont know if it was leaking out of overflow because of all coolant flowing into resivour????i put cardboard undereath vehicle to see if i could find where it was leaking and it was dripping in the front right side.(driversside) but could not find the problem. If anyone could please give me some insight on my stating issue that would be great. my coolant isssue as well....thank-you verymuch

 

also the battery voltage is showing in car to be a little below 12when i try n start car

 

I say replace the battery.

 

thats what i thought but was told it wasnt replaced too long before i bought it. even tho it says original on the battery

 

The easiest way to find out if the battery is still good is to test it.
If you don't have the means to test it yourself, then take it to an AutoZone, AdvanceAutoParts, or OReilleys store and have it checked. It is a free service.

As far as the coolant, you can check your engine bay while the car is idling at normal temperature and visually/physically inspect both hoses coming to the expansion tank. That way you know and see exactly what's happening.
I know this is repetition for folks who read the forum for a while, but my expansion tank was leaking at the top end. The plastic nipple that the hose coming from the radiator hooks or slides on was severed. The coolant was dribbling on the side of the tank.

Also, the hose on the bottom of the expansion tank (the level sensor is there) could leak as well if the hose clamp isn't tight enough, or if the hose's inner lining got worn over time.
Of course, at the same time you should visually/physically inspect all of the coolant hoses.

 

thank_you that is what im doing at this moment. will check in later with answer

 

im now getting really frustrated because battery is fine and im really starting to think that it is the starter again even tho i just had it replaceed month ago!!!!!!!

 

The battery probably isn't the problem, check the ground connection on the battery and the ground connection to the body. Most starter problems have to do with the ground cable on the battery. If thats ok check the power and ground at the starter.

The coolant leak is most likely from the nipple at the rear crossover pipe, common leak on the 3.0L (slow leak) Take off the center engine cover and look behind the motor, if you can see crusted dried up coolant, locate that nipple where it is leaking. You can pull replace that nipple, its a PITA but its a cheap repair.