Will not start

Hello,

It sounds like the crankshaft angle sensor has gone bad and the computer is not turning the fuel pump on becasue it does not see the engine turning over.

Here is a guide that will show you what you are in for when doing the job:

https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

and

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor

and

https://www.2carpros.com/articles/car-cranks-but-wont-start

Here are some diagrams to show you how it is done on your car.

At left front of transmission housing.

Please let us know what happens.

Cheers, Ken

My 2006 Audi A6 does not start.

Is it cranking over and will not start or just will not crank over at all/nothing when key at starting position?

So I only had this car for three days, but I am stressing out about it already. I can start the car in the beginning of the day, then take me an hour to start it again when I stop the engine. Battery is good, I do not know what the problem is. can you please help?
Thank you.

You are describing the classic symptom of a failing crankshaft position sensor or camshaft position sensor. They commonly fail by becoming heat-sensitive, then they will work again after cooling down for about an hour. While driving, natural air flow keeps them cool. When a hot engine is stopped, the heat migrates up to those sensors and can cause them to fail until they cool down. This can happen on any brand of engine and is easily overlooked at a used-car dealership because they do not drive the cars long enough for the problem to become apparent.

There will usually be a diagnostic fault code set to indicate when a sensor circuit's signal is missing. The place to start is by having the fault codes read and recorded. The people at many auto parts stores will read them for you for free.

Thank you very much. Can you give me estimate price if I take the car to the shop after I get the code? Just an estimate price range.

Thank you again.

Sorry, I would like to, but there are way too many variables. The additional point of value is diagnostic fault codes never say to replace parts or that one is bad. They only indicate the circuit or system that needs further diagnosis, or the unacceptable operating condition. When a part is referenced in a fault code, it is actually the cause of that code about half of the time. First we rule out wiring and connector terminal problems associated with the sensor or part, before we order the part. Electrical parts can rarely be returned because so many are damaged upon incorrect installation, and the parts store does not want to risk selling you a defective part that someone else returned. For that reason, the mechanic has to be pretty sure that part is really needed.

The next problem is some sensors are really easy to replace. Many can be replaced on Chrysler and Ford products in two or three minutes. On some engines a lot of disassembly is required, and they can take well over an hour. Add the additional time to get to a sensor to take some voltage readings, and you might add another hour diagnostic time to the part replacement time. I am not familiar with Audi engines but I did find your crankshaft position sensor is listed in the "flat rate" guide as taking 1.1 hours for just the replacement. That tells me it is a pretty involved job.

Remember, nothing has been diagnosed yet either. There are a number of computers and electronic modules that can cause a crank/no-start. I only jumped on the sensors because the failure only when hot is such a common symptom with them. No conscientious mechanic would waste an hour of your dollars based solely on the symptoms. If he is wrong, how are you going to feel when he tells you your money was wasted on his guess? Worse yet, how is he going to feel when you call the shop and tell him the problem occurred again when you are twenty miles from the shop?

I find that there is no signal or power to the fuel pump or fuel pump relay. what could be possible causes of this?

Hi HUGODB,

While you are waiting for one our experts to answer your question here is a link to an informative article from this site with step by step instructions and pictures and a video on what to check for when your vehicle cranks, but will not start.

https://www.2carpros.com/articles/car-cranks-but-wont-start

If you need any further help please come back to the site as we are always happy to help.

Thank you for visiting 2CarPros.

Kindest regards,

Renee
Admin

Sounds like only starter is turning.

maybe starter drive has failed (slipping).

2001 Audi A6 six cylinder all wheel drive automatic 106,00 miles.

Been driving well for the last three years with no problems. I went to start my car the other morning and it would not start. i have a new battery in the car and it still will not start. it did try to turn over but now it just whines when i turn the key. all power is good. all of the fuses are good. just want to have an idea to what it may be and what money i may put out. thank you

Starter fault. the whine is motor turning but pinion gear not engaging flywheel.

My battery is now finally starting to drain, would that have anything to do with my alternator?

Go to Auto Zone have alternator checked then you will know. Also if alternator good may have drain caused by a circuit staying on when key off. Like trunk light, glove box etc.

2001 Audi A6 six cylinder all wheel drive automatic 70,000 miles.

I tried to start the car jumping with my other car but the only noise i hear is like a woodpecker. lights inside working good deems a little when attempting start. Can anyone give me an idea what to do and look for next? I would really appreciate it.

Fuel and Spark:
Get a helper disconnect a spark plug wire or two and ground it to the engine at least 3/16 away from ground -have helper crank engine over do you have a snapping blue spark? If so you have a fuel related problem, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs,coil's resistances,distributor pick-up coil, ignition control module, cam and crank sensors and computer.

My 2000 Audi A6 2.8 V6 having trouble starting in a really cold weather.This problem occurs for past six years. Previous owner took car to dealership five times they could not find the problem.
When you try start the engine the starter cranks but the engine will not start (sounds like "dry" crank). After several attempts the engine starts but misfires, shakes, backfires. If you let engine run for minute or two and turn it off, it will start back up without any problems. Mechanics at dealership tried change spark plugs, plug wires, couple injectors, flushed the fuel system tested computer. the same result.It runs okay and starts when the engine is warm, but in a cold winter morning no.
I put new spark plugs, Karlyn wires, Karlyn ignition coil pack, new battery-the same problem. it takes ten to fifteen times of cranking until you get engine run. After it runs for minute or two no problems, starts right away. Yesterday I took to shop, hooked up computer and everything works fine,no cylinders misfiring O2 sensors okay ,fuel system okay, everything normal. We deleted faults. This morning the same problem it will not start and the check engine light came on. Please advise. Thanks.

First check fuel pressure with mechanical gauge. Some engines have a "cold start valve" which only works when cranking adding addition gas to engine when cold.

Newer engines simply increase injector pulse time, which is controlled by PCM.

But, I would start with fuel pressure check.

2000 Audi A6 six cylinder four wheel drive automatic 128,000 miles.

On they way back from a long trip, I saw a check engine light. I disconnected battery to reset trouble codes. Did not work, and car will not start. Help!

To find out what is wrong scan the computer for OBD2 code/s this is your starting point.

I have a 2001 Audi a6 2.8 Quattro that will crank, but will not start. Tried jumping. Recently changed the starter and ignition switch. Fuel pump has power at pump, but is not activating when I turn the key. Power windows, roof, and AC/heater are not working, and when I turn the key, the gauges do not move accordingly. Do you think it is just the fuel pump or some sort of electrical or fuse/relay issue?

Earlier in the day the car would not turnover, but did with a second attempt and drove home with no problem.

Previously the car had occasionally periodically turned over on ignition, then immediately shut off, but would fire back up and run and drive as expected.

Please help!

Scan for any fault codes. have the pump checked as last post suggests check for spark and injection pulse as well. post the results here for further assistance.

Turns out it was the ignition switch, again. Thanks for the advice though, much appreciated.

2000 Audi A6 six cylinder all wheel drive automatic 139,000 miles.

My car will not start after running, but if it sits for a few hours will start just fine. Please help!

Dose it crank? is it a slower crank speed than when cold? How old is battery? battery voltage?

It cranks very good it is not a battery issue. but when it has seat for a few hours it seems to start just fine, you can smell a lot of fuel though. Please help.

Every morning the car is crank about five to seven seconds before start.
Just happened a couple days ago, the morning my car start normal, i drove it a couple feet, than the engine stop. I try to start again, but will not start.
Checked the gas , was a little low, but about quarter of tank.
about ten minutes later the car just start, and run all day, but after that happened the same crank problem is keep coming back every morning, and when i stop more than twenty minutes.I was ask my Audi mechanic, he checked test the car, no system errors, no check engine light, nothing. He said have to change the fuel pump. i am not sure because the car runs, so the fuel pump is functional all time. I was checked myself the tank cap gasket have a little bit a crack on it, so could be a little leak, what cause the problem? the other idea was put some Techron in to the fuel to clean the system and injectors, what seems to be good the car running smother but did not fix the problem.
I hope you get enough info to help me out.
thanks

could be a bad check valve in the fuel pump. could be a bad pressure regulator bleeding down overnight. could be a bad coolant sensor as well.

you need someone with a scan tool to monitor these functions to verify.

Roy

Thanks

Do you think i can just check the check valve with out change the fuel pump?
Because that was the first quess , the check valve, after start the car runs.

there is a pressure regulator on the fuel rail. the check valve is part of the fuel pump.

i would not guess as it is expensive and most of the time wrong

Roy

After a time running my car I turn off the engine and later when I try to turn on the car didn't start. Then I waited for a minutes tried again and the car started.

When you say it did not start do you mean not crank over or crank over and not start?

Cranks over but does not start. I used the scanner to check the car and the scanner found problems with the camshaft position sensor. I already change it and the problem is still hanging around. Somebody told me to change the crankshaft sensor.

Yes, the crankshaft sensor is a common problem with an engine that does not start. Here is a guide that shows how the procedure is done:

https://www.2carpros.com/articles/crankshaft-angle-sensor-replacement

Please let me know if that worked.

Hi there, I have an Audi A6 that will not start I am 98% sure it is because of the starter because it is an manual and I push start it. But when I get it started if I do not give it a lot of gas it turns back off. Going around a corner or when stopping it turns off.

Why do you suspect the starter? Does it not work at times?

As far as the engine shutting down, have you checked for vacuum leaks and check the idle air control valve (IAC)? The IAC is what is responsible for maintaining the engine's idle.

The reason I think it is partly because of the starter is that when I turn the key it does not crank the motor at all I do not hear any noise either. But what could be the reason for the whole car shaking crazy?

The shaking could be from many things. When was the last tune up?

As far as the starter, when it does not work, you need to check to see if it is getting power. Have a helper turn the key to the start position while you check for power to the smaller wire on the starter. It should have twelve volts.

How can I tell if the power is getting to the starter? What is that I am suppose to look for?