wagonpitt

Hello all im new to the forum and appreciate any help. I have a 2007 a6 avant 3.2l since november 2015.
About a month into owning i tried to start, it cranked, everything worked but wouldnt start. It would take about 2 to 5 min of waiting and then it would start right away perfectly normal. It would only happen every few weeks.
As time has passed it happens more frequently and needs longer and longer sitting time before it starts.

About 3 weeks ago
I took it to my mechanic and after many hours looking around. He said the fuel pump intermitently(randomly) doesnt get power but not sure why. Hes sure its not the fuel pump itself and he checked the hoses and conectors. He believes its either the fuel pump module or the ecu that randomly doesnt give power to the pump when trying to to start. He recomended i bring it to audi for a propper diagnosis before making any expensive decisions.

2 weeks ago
I towed to audi because the battery died throughout the testing he did and had no time to charge it befor audi appointment. The audi dealership cheked the module, computer and wires and connections and said everything is fine. They said the battery is dead and wont hold a charge so i need a new one (450+). I took the battery out charged it 20 min and put it back in 2 days later. The car started fine and I spoke with audi again and told them the battery was fine and holding a charge. They told me that because the first time the cheked it was dead they basically not going to do any more tests while i have the same battery.

Within last week.
Since taking it back from the dealer ive had the issue twice. Both times i had to let it sit over night. I dont think its the battery because when it doesnt start i sit in it for 10. 15 minutes at a time sometime several times a day or night having a smoke listenig to music keeping heat on and trying to start over and over and the battery never dies . Just the car doesnt start either. I would think if it was bad battery it would die out after a few cranks for few minuts of heat and music. Id hate to pay for a new battery when this 1 seems perfectly fine. But id also hate to spend more money trying to figure something out and the solution is so simple . Does anyone have any thoughts or similar experiences. Is it possible for the battery to somehow just be bad even though it functions right ( charges/ holds charge ) and is it possible a battery can cause this issue ? Also audi never said its the battery . They just said it wouldnt charge and needs to be replaced to run further tests . Which makes me feel they just want me to pay for a new battery since i have chatged this one with no issues .

I searched and searched and any similar issues ive come across dont match. From what i understand it could be the ?crank or cam? position sensor but mechanic cheked it it was fine. Starter fine. Alternator fine. I read about immobilizer issues but those throw codes and bkth he and audi didnt find any. If it was a key recognition problem id assume audi would get a code for that. Ive read about a similar issue and the problem was a sensor in the steering column the person had to replace the entire column to fix it but im not sure what this is called and i dont want to replace a steering colum just as a guess.

Thanks for taking the time to read id appreciate any help tips comments.

wagonpitt

Short clip of cranking

wagonpitt

Sorry thats one of the possible problems im going to have to look into.

wagonpitt

This is my clip.

wagonpitt

Anybody somebody.

darr741

I have a 2007 Audi A4 manual 6 speed.. I am having the same problem where it starts sometimes and sometimes it dont. Have to wait an hour or two for it to start. I changed my crankshaft position sensor and my purge valve. Still having the same issue.

raj99

first thing you should do is post codes from a VCDS. When we can view that, we can provide insight on what it could be. It could be anything from mechanical to electrical...and before you start throwing parts at the problem, get some diagnostics.

Shamoye Lewis

its not the crank sensor because the rpm gauge went up a bit meant that those are fine, what Im not hearing it the coils ticking.... turn the ignition on, unplug the plug from the coil, you don't need to remove the coil then see it there is power in any of the leads, usually you just need to check the fat wires, read with a line but just check all if there is no 12v or 11v or what every charge your battery has left, look in the fuse box on the right of the DASH you will see ignition and injector fused check them.... if they're good spray some carburetor cleaner into the intake and see if it starts or the engine ignite, you are missing gas or spark, access control is good else the steering wouldn't unlock and the engine would not crank, just check all the fuses on the right they responsible for the engine management...

wagonpitt

Can you recomend a scanner that will work with my car. Ive read on the forums that the ross tech is the best one, but to support the c6 its the 350$ version and im not to happy about that. i realize i do need a scan tool to atleast have an idea of what problems i could be having. Like today check engine light for some reason i dont know yet. Let me know what you think is my best option.

wagonpitt

I ended up changing the battery after all.
For the first two days no problems whatsoever it would start on the forst crank. Third day i went to the store for 5 minuts, come back, crank no start. I tried again same thing. 20 sec later i try and starts up perfect.
Since then (about 1 week) ive had the issue once and it took a few hours to start again and a second time it took only about 10 sec of waiting.

Also as i mentioned when i first replaced the battery for the first 2 days it was starting up on the first crank . Since the third day of new battery when it didnt start, now when it does start its alittle bit more lazy and will start on second or third crank instead of first like when battery was brand new.

I havnt taken it back to mechanic or dealer yet and i realize i do need a scanner so i can help you guys help me. Im going to take it in for an oil change and see if i can get a printout of any codes that might show up but from what ive been told by mechanic and audi dealer nothing shows up. If someone can recomend a scanner that i should buy id appreciate that. I looked at rosstech but 350$ id rather not unless i absolutly have to.


Thanks again for any idea tips.