Crankshaft position sensor locations - Top vs Bottom - which engine bank ?

[mattsimis]

Im still getting a fault on Bank II (Cylinder 7-12) on my CSi. I need to know which crankshaft (ie not cam position) engine speed sensor refers to which bank of the engine?
I replaced the sensor connected on the left (as facing engine) which routed down to the bottom crankshaft sensor position (as the PS pump). Does this feed into to Cylinders 1-6 or 7-12?

I dont think its connection position at the oil filler cap can be used to determine placement/bank btw, as they seem to vary layout per car. But the position on the toothed wheel should be the identifier right?

[ByMW]

Standing at the front of the car, looking toward the back, cylinders 7 to 12 are on the left.

As you know, both the crank position sensor and cylinder ID sensor attach to plugs under the oil filler cap, and these plugs look the same. I never disconnect more than one at a time for fear of getting them confused!

[mattsimis]

Thats not quite what I was asking though, I need to know which Crankshaft sensor (top or bottom) is picked up as a Bank2 fault. Both sensors are physically on the right side of the engine, when facing it.

Also, I dont think your description is correct anyhow, according to Meeknet:

http://www.meeknet.co.uk/E32/V12_Distributor_Leads.htm


Again though, I need to know which Crankshaft sensor corresponds to which bank!

[Ahmed303]

Regardless of air intake feeding the opposite banks, I am thinking logically. Thinking of each side as a inline 6 and not looking at the intake manifold.

With that logic, the sensors should be side specific. So left side of the engine (head, pistons, etc.) will respond to the left sensor and right to the right. The following pictures may help understanding what I am thinking.

Good luck.

[Nkana]

These might help - copied from an engine rebuild post some years ago

This is a view of the right side Pulse Sender (top) (goes to the left side of the block) and Cylinder Identifier 1 through 6 (bottom) still plugged in, but with the bolts taken out.

The big hose is a by-pass hose from the intake manifold to the radiator.

1.jpg

This is the Pulse Sender and Cylinder Identifier removed from the clips that are used to bolt them to the Cylinder Head. Note the black clip on the top and the tan on the bottom; don’t cross them.

2.jpg

This is a view of the left side Pulse Sender (top) and Cylinder Identifier 7 through 12 (bottom) with the bolts taken out.

3.jpg

This is the Pulse Sender and Cylinder Identifier removed from the clips that are used to bolt them to the Cylinder Head. Note the black clip on the top and the tan on the bottom; don’t cross them.
4.jpg

which ties in with the E31 repair manual available at http://www.wuffer.ca/

5.jpg

[Ahmed303]

This picture from Wokke may also help.
191.jpg

[mattsimis]

Cool photos thanks. The wokke photo with the coloured boxes shows how mine is setup, I changed the "blue" sensor, which was connected on the left (when facing) side of the engine. In hindsight, not only was this vastly more difficult to change, it also possibly wasnt correct if we assume the connection location on the left referring to cylinders 1-6 and not to cylinders 7-12 (bank 2 like the error says).

- Is that really a safe assumption though, that the connects are simply mounted per side?
- The slight confusion about which cylinder is which still remains, for now Im trusting the Meeknet photo above, "RHS 1-6" is the side of the engine the connector I changed was on.

5.jpg

This is my concern as thats not how mine have ever been connected (3 and 4 are reversed top to bottom) and Ive seen it posted here the layout actually doesnt follow a system, hence my hesitation to believe the positioning one way or another.

[Ahmed303]

- The slight confusion about which cylinder is which still remains, for now Im trusting the Meeknet photo above, "RHS 1-6" is the side of the engine the connector I changed was on.

Logic tells me you would be correct. I think you will need to change the "Red" for 7/12. The reason the meeknet picture will be correct is because of context of "spark".

[perelet]

As everybody suggests - replace all 4 of them, use OEM parts. Your car bad manners will be greatly improved. Also crank sensors usually give no codes - just no start. Cam/pulse donuts are the ones that make run on one bank and "Trans Save" displays.

Here are more pics on replacing both.

Oleg.

[ByMW]

Forgive me, you are correct. I had the cylinder numbers reversed.

[mattsimis]

As everybody suggests - replace all 4 of them, use OEM parts. Your car bad manners will be greatly improved. Also crank sensors usually give no codes - just no start. Cam/pulse donuts are the ones that make run on one bank and "Trans Save" displays.

Here are more pics on replacing both.

Oleg.

I posted another thread on the actual problem, but I have replaced 3 of the 4 sensors (ok 2 donuts from Magnetec and 1 Crankcase pattern part) and have the last Crankshaft sensor (OEM this time) on its way to me right now. While I get that an outright dead sensor would give a no start, if the sensor is intermittently failing (or the wiring, but I traced it all back to the DMEs... again!) then the car cuts power to the fuel pumps = complete loss of power when driving. If you start your engine, pull one of them you will find it doesnt cut out, but it audibly starts making weird sounds as the bank dies and RPM gets locked.

I dont get Trans Save messages as I have a manual. Ive even troubleshooted the occurrence of the Code 10/power drop out fault, its only when holding RPM steady, ie motorway driving! Backroads hard driving is up and down the powerband = no issues. Weird hmm?

[ChrisFuture8]

The CPS for bank two is the bottom one. The easiest way to figure out which connector is the CPS vs the CID on each bank is by tracking the CID wire from the doughnut shape end to the connector end. Once that's established, the other connector (on the same side of the motor of course) is then the CPS.

Cheers.

[mattsimis]

The CPS for bank two is the bottom one. The easiest way to figure out which connector is the CPS vs the CID on each bank is by tracking the CID wire from the doughnut shape end to the connector end. Once that's established, the other connector (on the same side of the motor of course) is then the CPS.

Cheers.

Not quite following you.. when you say "bottom one" are you referring to the plastic connector position or the Crankshaft Speed Sensor? The vague consensus we came to above is that the bottom Crank sensor is Bank1? You seem to be saying the opposite. If you are correct then I have a bigger problem as Ive already replaced that Sensor. If the thread is correct then the issue simply is I replaced the wrong sensor.

The question isnt about the connector side, irrelevant of the image above I know where my connectors connect.



Also "CID"? I did a google for BMW CID and got "Central Information Display".. no one used the term CID above either. The misleading terms is why I was writing out Crankshaft vs Cam Position Sensor as opposed CPS (or other acronyms).

[Ahmed303]

CID = Cylinder Identification (AKA Crank Position Sensor). I still think that you simply replaced the wrong sensor and used a non E31 sensor to replace it with which may have started to give you more trouble. I think that's the best logical diagnosis I can give you from all these miles apart.

[mattsimis]

CID = Cylinder Identification (AKA Pulse Sender). I still think that you simply replaced the wrong sensor and used a non E31 sensor to replace it with which may have started to give you more trouble. I think that's the best logical diagnosis I can give you from all these miles apart.

Yeah I agree with you, but its ChrisFuture's post that is throwing the spanner in the works! I have 2 sensors on their way now.

[Ahmed303]

Actually I take that back. CID is the Crank Position Sensor and not the Pulse Sender. I think the CID acronym was to differentiate from the CPS (Cam Position Sensor). Sorry about the mini confusion.

I am still having a hard time comparing the Wokke picture with the picture of the repair manual. I can double check in my car but I think the connector ports by the oil caps are color coded (beige and black) for a reason.

[mattsimis]

Actually I take that back. CID is the Crank Position Sensor and not the Pulse Sender. I think the CID acronym was to differentiate from the CPS (Cam Position Sensor). Sorry about the mini confusion.

I am still having a hard time comparing the Wokke picture with the picture of the repair manual. I can double check in my car but I think the connector ports by the oil caps are color coded (beige and black) for a reason.

Thats still confusing if you read his post as he talks about following CID wire from donut. Donuts are on the Cam Position Sensor. I actually think the more people chime in the more we move from clarifying this.
Also on the colours of the female connectors under Oil filler, IRC both bottoms are beige which doesnt align to their function as on mine (top or bottom) one side is Cam and other Crankshaft.

[mr93465]

Don't go by the color code, it is not correct. Just had that issue with my car. The mechanic made a mess of rewiring everything so I was replacing the wires correctly, I thought it made sense to follow the color code. Luckily I then looked at the repair manual. They are opposite. REFER TO THE PHOTO CODING not the colors

[Ahmed303]

Thats still confusing if you read his post as he talks about following CID wire from donut. Donuts are on the Cam Position Sensor. I actually think the more people chime in the more we move from clarifying this.
Also on the colours of the female connectors under Oil filler, IRC both bottoms are beige which doesnt align to their function as on mine (top or bottom) one side is Cam and other Crankshaft.

Don't go by the color code, it is not correct. Just had that issue with my car. The mechanic made a mess of rewiring everything so I was replacing the wires correctly, I thought it made sense to follow the color code. Luckily I then looked at the repair manual. They are opposite. REFER TO THE PHOTO CODING not the colors

Yup! I guess color coding does not matter. Both the bottom ones are beige and tops are black in my car. I will check this evening on connections as they are in my car. The last I remember it was like the Wokke picture.

[ChrisFuture8]

CID = cylinder ID sensor (the one with the doughnut shape metal piece)
CPS = crank position sensor

NOTE:
Without the CPS sensors working (especially critical for bank 1) the engine will not start no matter if both of your CID sensors are working.

Now, both the CID and CPS sensors are routed to the front of the engine block, and connected to the connectors which run back to the DMEs, right?
When standing in front of the car and facing the engine, we have established that the left side is bank one and right side is bank 2.

For bank 2, the CPS sensor plug is the bottom one and that leaves the top plug the CID sensor. As I stated earlier, ( whether bank 1 or bank 2, you apply the same method) the easiest way to figure out which plug is which is by tracing the CID doughnut sensor from the cap/rotor to the connect at the front of the block. That then leaves the other plug to be the CPS. I know this is all very confusing without proper pictures.

Cheers.

[mattsimis]

CID = cylinder ID sensor (the one with the doughnut shape metal piece)
CPS = crank position sensor
NOTE:
Without the CPS sensors working (especially critical for bank 1) the engine will not start no matter if both of your CID sensors are working.

Now, both the CID and CPS sensors are routed to the front of the engine block, and connected to the connectors which run back to the DMEs, right?
When standing in front of the car and facing the engine, we have established that the left side is bank one and right side is bank 2.
For bank 2, the CPS sensor plug is the bottom one and that leaves the top plug the CID sensor. As I stated earlier, ( whether bank 1 or bank 2, you apply the same method) the easiest way to figure out which plug is which is by tracing the CID doughnut sensor from the cap/rotor to the connect at the front of the block. That then leaves the other plug to be the CPS. I know this is all very confusing without proper pictures.

Cheers.

Thanks for the detail Chris.. I guess the slight confusion is you are answering a slightly different question, ie the question isnt which plug is which. Its confirmation which "CPS" position (as located on top of the toothed wheel or bottom) is routed to which Bank (1-6 or 7-12).
To reuse the earlier image (which isnt quite how mine is setup, but for the purposes of general clarity), would you agree that this is correct:



I have an error on either (as annoyingly Peake doesnt know for sure) "CID" or "CPS" on Cylinder 7-12 bank. However, in my ignorance I replaced what the image above calls "Plug 2" which on my car is the CPS routed all the way down at the PS Pump (bottom CPS). I have already replaced both "Cylinder Identifiers" donuts (aka CID in this parlance, correct?).

[perelet]

.... I have already replaced both "Cylinder Identifiers" donuts (aka CID in this parlance, correct?).

Matt, replacing donut sensors is pretty tricky task, to do it right you have to use right Beru crimper and wire push tool (tools alone cost me about $500, but I also have 90 Porsche 964 which has dual spark plugs and uses similar Beru setup). You can see parts and Beru part numbers in my thread above.



If you do not crimp and push/click spark plug wire tight - you'll be having even more gremlins. You'll get misfires, miscounts of cam position in DME - and subsequent misbehaviours.


Oleg.

[mattsimis]

Matt, replacing donut sensors is pretty tricky task, to do it right you have to use right Beru crimper and wire push tool (tools alone cost me about $500, but I also have 90 Porsche 964 which has dual spark plugs and uses similar Beru setup). You can see parts and Beru part numbers in my thread above.
If you do not crimp and push/click spark plug wire tight - you'll be having even more gremlins. You'll get misfires, miscounts of cam position in DME - and subsequent misbehaviours.

Oleg.

As I said, this is done, twice infact (once with Generic leads using original Donuts then with the Magnecors which come preinstalled with new Donut sensors). I used a Wire Crimp when I did it and it was fine, no need for $500 wire pusher tool!? I assume the Magnecor guys do a pro-job on it too.

[Ahmed303]

I checked my setup last night and it is just like the Wokke picture.

[mattsimis]

I checked mine last night too and found that despite what I said earlier, my layout is the same the diagram above and I had infact changed the right (#4, bottom sensor) CPS, not the left (top sensor) CPS like I stated. Which means I have changed the right one which in turn means either the part I put in doesnt work correctly or I have some other problem. Last night I replaced the left (#1 in image) with the new part (PN was per E31 this time).

On the plus side I guess I can now put in the sensor that was in position #1 and see if the problem goes away. Ive ordered another one anyhow.