Hey guys,

So I have a 2006 Audi A6 s-line 3.2L.
Last night I tried starting it but it won't start... I get this clicking noise, and my cd player turns on and changes disks or something ....

I jumped my car and it turned on, but when I turned it off and tried turning it on again it wouldn't turn on...

so do you guys think it's the battery or altenator ???
please help..

 

Could be either one (or worst case both). I would remove the battery and bring it to a local car shop like autozone. They will test it for free and tell you if it's any good. If removal is not an option for whatever reason - have someone follow you while you drive the car to your place of choice. If the car keeps running for more than 10 minutes while driving - it's likely a bad battery as a fully charged battery can move you for about 10 minutes without an alternator keeping it juiced up. Please note however that excessive strain on the alternator takes it toll so if you find out it's a bad battery take care of it quickly or save up to replace the alternator as well.

I had a battery that didn't show an issue until it completely died - at which point the alternator had been running constantly for weeks to charge it (while the battery couldn't take the charge or lost it almost immediately). Once I had it figured out I replaced the battery and within 1 month the alternator died from the stress to keep the old battery "alive".