Crankshaft Position Sensor

[cwmotorsport]

It seems that my a6 4.2 is having issues again as it just out of nowhere would not start after parking in my driveway for a few minutes. I have researched the issue and come up with a plan to replace the crank sensor. My car started up this afternoon and have ruled out the fuel pump (i think) as an issue due to hearing the pump prime upon turning the ignition. I would like to know where some of you guys have purchased the sensor as I want to make sure I get the correct unit. I have found the sensor for 2.7t, 2.8, nd 3.0 liter engines but none for the v84.2. Maybe someone can chime in and help me out. Thanks in advance for any direction...

[audifirst]

did you at least scanned your car with VAGCOM , some errors will not cause CEL to light up the icon, they will register in system ?

[G Men 08]

any more information? Kind of tough to help with a "it wont start" description.

[cwmotorsport]

the car just cranks and won't turn over.I live about 2 hrs away from the nearest audi shop and would like some info. on what mite cause the issue before hand. I had a local shop look at it. They sprayed starter fluid in the car and it started up a bit rough and then smoothed out after. I understand that its not good to spray either into the engine for it mite cause issues. I've read a few posts of guys with the same problem and it was either the fuel pump or the cps. I do not have a vag tool to check codes. I'm going to purchase one very soon but I know that a bad cps does not always throw a code. I did replace the fuel filter as it was clogged pretty good but thats all i've done so far...

[Audi_Tech]

the car just cranks and won't turn over.I live about 2 hrs away from the nearest audi shop and would like some info. on what mite cause the issue before hand. I had a local shop look at it. They sprayed starter fluid in the car and it started up a bit rough and then smoothed out after. I understand that its not good to spray either into the engine for it mite cause issues. I've read a few posts of guys with the same problem and it was either the fuel pump or the cps. I do not have a vag tool to check codes. I'm going to purchase one very soon but I know that a bad cps does not always throw a code. I did replace the fuel filter as it was clogged pretty good but thats all i've done so far...

When the concern happens check your RPM gauge, if you have no reading then your crank sensor is faulty and no spark is supplied to the engine since it doesn't "see" that the crankshaft is turning. There will also be no fault the sensor unless there is a short circuit in the sensor/wiring.

[A62TURBO]

It could be a number of things, get it scanned and take it from there.

[mithril]

I would like to know where some of you guys have purchased the sensor as I want to make sure I get the correct unit. I have found the sensor for 2.7t, 2.8, nd 3.0 liter engines but none for the v84.2. Maybe someone can chime in and help me out. Thanks in advance for any direction...

The part # for the V8 CPS is 077 905 381 F. ECS sells them for $137.75 + shipping: http://www.ecstuning.com/Search/077905381F/ES283065/

As others have mentioned, it could be a number of things however the CPS is the cheapest and easiest of them to replace so if you really don't have the ability to scan for codes that's a better place to start than the fuel pump (for example). As Audi_Tech said, if it's your CPS you won't see any movement in the RPM guage while cranking the engine. You also won't hear the fuel pump prime as a dead CPS sensor will tell the the ECU to cut both ignition and fueling. That was the case with my 4.2 when it died earlier this month with the same symptoms as yours, CPS replaced and it's back without any issues.

[greenarmyman]

The part # for the V8 CPS is 077 905 381 F. ECS sells them for $137.75 + shipping: http://www.ecstuning.com/Search/077905381F/ES283065/

As others have mentioned, it could be a number of things however the CPS is the cheapest and easiest of them to replace so if you really don't have the ability to scan for codes that's a better place to start than the fuel pump (for example). As Audi_Tech said, if it's your CPS you won't see any movement in the RPM guage while cranking the engine. You also won't hear the fuel pump prime as a dead CPS sensor will tell the the ECU to cut both ignition and fueling. That was the case with my 4.2 when it died earlier this month with the same symptoms as yours, CPS replaced and it's back without any issues.

resurrecting a dead thread :) How hard is this sensor to replace? Where is it located?

[mithril]

It's just in front of the bell housing on the drivers side, 10mm nut IIRC. Remove the fender liner and it should be pretty obvious.

[Met]

The part # for the V8 CPS is 077 905 381 F. ECS sells them for $137.75 + shipping: http://www.ecstuning.com/Search/077905381F/ES283065/

As others have mentioned, it could be a number of things however the CPS is the cheapest and easiest of them to replace so if you really don't have the ability to scan for codes that's a better place to start than the fuel pump (for example). As Audi_Tech said, if it's your CPS you won't see any movement in the RPM guage while cranking the engine. You also won't hear the fuel pump prime as a dead CPS sensor will tell the the ECU to cut both ignition and fueling. That was the case with my 4.2 when it died earlier this month with the same symptoms as yours, CPS replaced and it's back without any issues.

Hey guys i have an 07 audi a6 3.2fsi and im having the same problem as the firts guy describes my car stars when it wants to sometimes after 3-5 tries and it starts sometimes it starts right up sometimes i have to wait like 10-15 mins than it will start but lately its been getting worse this is what it does i try to start it and it cranks normally it just wont fire and another problem is that i can let go of the key it will crank by it self i put the key to off position it stops any help would be appreciated thankyou.

[SDchargers]

When the concern happens check your RPM gauge, if you have no reading then your crank sensor is faulty and no spark is supplied to the engine since it doesn't "see" that the crankshaft is turning. There will also be no fault the sensor unless there is a short circuit in the sensor/wiring.

This is not entirely true. I bought a new crank position sensor and installed it and there is still no changes. Car will crank fast but won't start. The tachometer does not move at all when cranking the car. My next course of action will be to order and swap out two new crank position sensors.

[alien_brain]

theres also cam position sensors that have similar control over starting to the crank position sensor