1995 Audi A6 engine speed sensor location help
#1
10-06-2010, 04:32 PM
1995 Audi A6 engine speed sensor location help
hi, I own a 1995 Audi A6 2.0 ABK. The car has been diagnosed with an engine speed sensor fault.
On contacting Audi I was told that the speed sensor if the same as a crankshaft sensor.
I have looked all around the bellhousing and cant find it.
can anyone help please
On contacting Audi I was told that the speed sensor if the same as a crankshaft sensor.
I have looked all around the bellhousing and cant find it.
can anyone help please
#2
11-19-2010, 08:10 PM
It is not on the bell housing but on the engine very close to the bell housing. See the illustration from Bentley.
#4
11-20-2010, 07:57 AM
Uh, the crank position sensor is not the same as the vehicle speed sensor (although, mathematically, the vehicle, meaning engine, speed can be derived from the crankshaft position sensor readings, but I digress...). I believe that, in the C5 vehicles, the crankshaft position sensor was replaced by camshaft position sensors. I would go with the drawing ManyAudis presented, which looks even harder to get to than the crankshaft position sensor in Chefro's photos.
Good luck,
Bob
Good luck,
Bob
#5
11-21-2010, 04:14 PM
I was living under the impression that the vehicle speed sensor is in the wheel hub... also known as the ABS sensor.
As far as I know, the engine speed sensor is also known as the crankshaft sensor. If it was true that the "engine speed" would be given by the cams' movement and positioning, hence the use of camshaft sensor(s), then what's the point of having another engine speed sensor, a.k.a. the crank sensor?
As far as I know, the engine speed sensor is also known as the crankshaft sensor. If it was true that the "engine speed" would be given by the cams' movement and positioning, hence the use of camshaft sensor(s), then what's the point of having another engine speed sensor, a.k.a. the crank sensor?
#6
11-21-2010, 05:36 PM
I was living under the impression that the vehicle speed sensor is in the wheel hub... also known as the ABS sensor.
As far as I know, the engine speed sensor is also known as the crankshaft sensor. If it was true that the "engine speed" would be given by the cams' movement and positioning, hence the use of camshaft sensor(s), then what's the point of having another engine speed sensor, a.k.a. the crank sensor?
As far as I know, the engine speed sensor is also known as the crankshaft sensor. If it was true that the "engine speed" would be given by the cams' movement and positioning, hence the use of camshaft sensor(s), then what's the point of having another engine speed sensor, a.k.a. the crank sensor?
The engine speed sensor + the cam sensor (and some cars have an additional 1/rev crank sensor) are used for getting the timing information for the injectors and ignition system. Unfortunately I do not have the Bentley for the 1995 2.0 engine (not shipped to USA) but the engine speed sensor has been the same for a long time. It looks like what I posted and like the photos posted above. It is very similar looking to an ABS sensor and it senses the gear teeth on the flywheel starter ring. This just gives the engine speed. The 2.8 12V engine also had a crank position sensor to tell the system when TDC was reached. The crank position sensor looks just like the engine speed sensor and is mounted nearby. It read the position of one of the crank counterbalance weights I believe.
All three signals needed to be present to start the car - Crank position sensor, engine speed sensor and Cam position sensor. Once the car was running the Cam position sensor could fail and the car would continue to run, the MIL light would come on and then the car would not start again.
If the 2.0 is like all other engines from that year the speed sensor will be on the rear of the engine near the bell housing on the left side.
Last edited by ManyAudis; 11-21-2010 at 05:43 PM.
#8
01-16-2012, 07:51 AM
95 Audi 2.8 engine sensor procedure
Sorry for the length of this, but I hope this post works. I am not an Audi guy but a family friend brought one to my house with an intermittent starting problem. I could not find a procedure on how to do this job so I wrote one in an attempt to help others. If this procedure is posted in the wrong location please move it where others can find it. Thanks.
95 Audi 2.8 engine speed sensor location
Symptoms: Car will turn over, but will not start. However it may start perfectly fine the next day. Check engine light code points to engine speed sensor.
Note that this is a tough job. 8.5 on a scale of 10. The sensor is located 18” in through an opening that is 5” x 5” This means when you reach in you scrape the skin off of your elbow and forearm. The job may have been easier if the driver side exhaust was disconnected from the manifold. I worried that the bolts would have broken making the job bigger than it already was.
1. Raise the car on jack stands. Use good jack stands on structural parts of the frame. Your life depends on this part of the job. Chock the back wheels to prevent the vehicle from rolling.
2. Remove the front drivers side tire.
3. You now have “very limited” access to the place where the sensor lies.
a)Through the wheel well there is a hole where the upper tie rod passes through. I inserted a trouble light here.
b)From underneath and behind the wheel well there is access. This is the access point that is used. It helps to be right handed. (I am not)
4.The first obstacle is a heat shield that protects the sensor from exhaust heat. This requires and 8mm combination wrench. The upper one broke free easily. The lower one required three different vice grips to break it free. Much of this work is done by braille. Because once you put your arm into the opening you can not longer see what you are doing. After the two 8mm bolts are removed the heat shield will fall out of the way.
5.The next obstacle is the 10mm bolt that holds the sensor in place. Note that the bolt faces the driver’s side of the car. From drawings that I had seen, I thought that it faced the rear of the car. Once the bolt is removed. The sensor is still hard to remove because there is no way to grab it. A lag screw turned into the hole by hand allowed me to grip the sensor and pull it.
6.New unit included extra o-ring and washer not used on old unit. Since this is a proximity device, the added O-ring & washer would change the proximity. Therefore I did not use them. I left an o-ring that was mounted in a groove of the new unit. The old one had a groove but no o-ring.
7.From underneath the car I followed the sensor wire up towards the firewall. There is a spring clip that holds two sensor wires together. I used a screwdriver to pry the clip off of the engine part it was clipped on to. I removed the old sensor wire from this clip, leaving the clip attached to the sensor wire that travels with the one to be replaced. This allowed me to reconnect the clip to the new sensor wire in the correct location.
8.At the firewall I disconnected the two electrical connectors on the driver”s side of the cluster of connectors. These are disconnected by pulling or sliding the metal spring clip out of the way and then lifting the upper portion of the connector off of the lower portion. The lower portion then slides out of the metal mounting bracket. (towards the radiator) I tied a string around these two connectors before pulling them down and out of the bottom of the car. The string allows the connectors to be pulled back (with great difficulty) in the same routing path as they were before.
9.Putting the car back together is equally difficult. When repositioning the new sensor I temporarily used a longer bolt to get the pieces back in position. Then I switched to the original bolts.
10.The rest of the job is just putting things back. This car started right up when I was done.
11.The now running 1995 car ran rough. I searched and found 3 broken vacuum lines. These were replaced. One more safety tip. If you look for vacuum leaks using starting fluid, keep a fire extinguisher handy. Bad wires or hot exhaust can ignite the fluid.
Good luck.
95 Audi 2.8 engine speed sensor location
Symptoms: Car will turn over, but will not start. However it may start perfectly fine the next day. Check engine light code points to engine speed sensor.
Note that this is a tough job. 8.5 on a scale of 10. The sensor is located 18” in through an opening that is 5” x 5” This means when you reach in you scrape the skin off of your elbow and forearm. The job may have been easier if the driver side exhaust was disconnected from the manifold. I worried that the bolts would have broken making the job bigger than it already was.
1. Raise the car on jack stands. Use good jack stands on structural parts of the frame. Your life depends on this part of the job. Chock the back wheels to prevent the vehicle from rolling.
2. Remove the front drivers side tire.
3. You now have “very limited” access to the place where the sensor lies.
a)Through the wheel well there is a hole where the upper tie rod passes through. I inserted a trouble light here.
b)From underneath and behind the wheel well there is access. This is the access point that is used. It helps to be right handed. (I am not)
4.The first obstacle is a heat shield that protects the sensor from exhaust heat. This requires and 8mm combination wrench. The upper one broke free easily. The lower one required three different vice grips to break it free. Much of this work is done by braille. Because once you put your arm into the opening you can not longer see what you are doing. After the two 8mm bolts are removed the heat shield will fall out of the way.
5.The next obstacle is the 10mm bolt that holds the sensor in place. Note that the bolt faces the driver’s side of the car. From drawings that I had seen, I thought that it faced the rear of the car. Once the bolt is removed. The sensor is still hard to remove because there is no way to grab it. A lag screw turned into the hole by hand allowed me to grip the sensor and pull it.
6.New unit included extra o-ring and washer not used on old unit. Since this is a proximity device, the added O-ring & washer would change the proximity. Therefore I did not use them. I left an o-ring that was mounted in a groove of the new unit. The old one had a groove but no o-ring.
7.From underneath the car I followed the sensor wire up towards the firewall. There is a spring clip that holds two sensor wires together. I used a screwdriver to pry the clip off of the engine part it was clipped on to. I removed the old sensor wire from this clip, leaving the clip attached to the sensor wire that travels with the one to be replaced. This allowed me to reconnect the clip to the new sensor wire in the correct location.
8.At the firewall I disconnected the two electrical connectors on the driver”s side of the cluster of connectors. These are disconnected by pulling or sliding the metal spring clip out of the way and then lifting the upper portion of the connector off of the lower portion. The lower portion then slides out of the metal mounting bracket. (towards the radiator) I tied a string around these two connectors before pulling them down and out of the bottom of the car. The string allows the connectors to be pulled back (with great difficulty) in the same routing path as they were before.
9.Putting the car back together is equally difficult. When repositioning the new sensor I temporarily used a longer bolt to get the pieces back in position. Then I switched to the original bolts.
10.The rest of the job is just putting things back. This car started right up when I was done.
11.The now running 1995 car ran rough. I searched and found 3 broken vacuum lines. These were replaced. One more safety tip. If you look for vacuum leaks using starting fluid, keep a fire extinguisher handy. Bad wires or hot exhaust can ignite the fluid.
Good luck.
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