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BMW E39 Crankshaft Sensor Replacement
 

Pelican Technical Article:

BMW E39 Crankshaft Sensor Replacement

Kerry Jonsson

Time:

3 hours3 hrs

Tab:

$50

Talent:

*****

Tools:

Set of sockets, 5mm Allen bit, flathead screwdriver

Applicable Models:

BMW 525i Sedan/Wagon (2001-03)
BMW 528i Sedan/Wagon (1997-00)
BMW 530i Sedan (2001-03)
BMW 540i Sedan/Wagon (1997-03)

Parts Required:

Crankshaft position sensor, sealing O-ring

Hot Tip:

Work with a cool engine.

Performance Gain:

Car will run well.

Complementary Modification:

Change engine oil

The crankshaft position sensor is used to synchronize engine timing for fuel and ignition control. It is located near the starter motor, mounted in the engine block. The sensors read a toothed reluctor wheel mounted to the end of the crankshaft. It then sends a signal to the DME used to identify cylinder location. If this signal is missing, for example from a faulty crankshaft sensor, then engine will not start. You can consider the signal from the crankshaft sensor the RPM signal for the DME.

If you need to test your crankshaft position sensor, see our article on camshaft position sensor testing. It is very similar for both sensors and that article will help you test your crankshaft position sensor.

In this article, I'll go over the steps involved with replacing the crankshaft position sensor. On 6-cylinder models, you can access sensor from below vehicle, working on left side. On 8-cylinder models you can access the sensor from the lower right side of the transmission.

Models with 6-cylinder engine:

Raise and support front of vehicle safely. See our tech article on jacking up your vehicle.

Working below starter motor (yellow arrow) at left side of engine, disconnect crankshaft sensor electrical connector.
Figure 1

Working below starter motor (yellow arrow) at left side of engine, disconnect crankshaft sensor electrical connector. (green arrow)

Next, using a 5mm Allen bit, remove crankshaft sensor mounting fastener.
Figure 2

Next, using a 5mm Allen bit, remove crankshaft sensor mounting fastener. There is not a lot of room, so I use a short 5mm Allen bit with a 1Â" extension on my 1/4 drive ratchet.

Once Allen bolt is removed, pull crankshaft sensor out of engine block.
Figure 3

Once Allen bolt is removed, pull crankshaft sensor out of engine block. Be sure sealing O-ring comes out with sensor. If it stays in the block, retrieve it with a small pick. (yellow arrow) Install new sensor and sealing O-ring. Torque sensor to engine block 10Nm (7 ft-lb). Reconnect electrical connector and install engine splash shield. Start vehicle and allow it to idle for about 1 minute. Check that crankshaft sensor area is free of oil leaks. If your check engine was on, now is the time to clear any fault codes and you are done.

Models with 8-cylinder engine:
The crankshaft sensor is located at the bottom of the transmission bell housing on the right side.
Figure 4

The crankshaft sensor is located at the bottom of the transmission bell housing on the right side. (green arrow).

First thing is to disconnect the camshaft sensor electrical connector.
Figure 5

First thing is to disconnect the camshaft sensor electrical connector. To disconnect it, press the wire release tab (green arrow), then pull the connector straight out to remove. Next, using a 5mm Allen bit, remove crankshaft sensor mounting fastener (yellow arrow). You may have to use a swivel socket to access it, there is not a lot of room. You can see my vehicle had a 10mm bolt, this is not normal and someone has replace the factory bolt with this. If you find this, install a new fastener.

Once Allen bolt is removed, pull crankshaft sensor out of engine block.
Figure 6

Once Allen bolt is removed, pull crankshaft sensor out of engine block.

On 8-cylinder engines, the crankshaft sensor may be installed with a shim (green arrow), be sure this shim is reinstalled.
Figure 7

On 8-cylinder engines, the crankshaft sensor may be installed with a shim (green arrow), be sure this shim is reinstalled. This is to correct the air gap for the sensor to the reluctor on the flex-plate. If you replace the flex-plat or transmission, BMW wants you to measure the sensor (area between red arrow) to determine if it needs a shim. To determine shim size, measure length between red arrow, then subtract length of sensor from distance of mounting area to reluctor tooth (be sure you are on a tooth and not in a gap). The distance from the sensor tip to the reluctor should be 0.55 mm (0.0217 inches). Install new sensor. Torque sensor to engine block 10Nm (7 ft-lb). Reroute and reconnect electrical connector, be sure wiring harness is installed in metal clip at bell housing. Start vehicle and allow it to idle for about 1 minute. Check that crankshaft sensor area is free of oil leaks. If your check engine was on, now is the time to clear any fault codes and you are done.

Comments and Suggestions:
lojekd Comments: 2001 BMW 525i. Code P0339 and P0727. The scanner was showing crankshaft sensor failure. I replaced this sensor but nothing changed. What else can cause this problem? The car is little hard to start but while driving everything works fine except transmission which one is in safety mode position.
Ps. Engine speed starts to wobble when I put A/C in max position.
November 1, 2017
  Followup from the Pelican Staff: Bad wiring, faulty engine timing or DME issue. - Nick at Pelican Parts  
Ed Comments: You reference "our article on camshaft position sensor testing," but fail to provide a link.
August 8, 2017
  Followup from the Pelican Staff: This engine sensor configuration is similar. http://www.pelicanparts.com/BMW/techarticles/BMW-3-Series-E46/106-FUEL-Camshaft_Sensor_Testing/106-FUEL-Camshaft_Sensor_Testing.htm - Nick at Pelican Parts  
tommyb4444 Comments: hello . all . i have BMW E39 523i ,1997, and this is the second time i change the crankshaft sensor . and my car are the same . then i change the main computer located under the air condition filter . my car start good , then the crankshaft sensor . back again with code , any help ? please or advice . what is the problem . thank you
April 12, 2017
  Followup from the Pelican Staff: How is it failing? Physical damage or electrically? If electrically, you may have purchased a few defective parts. - Nick at Pelican Parts  
Baz77 Comments: today i was driving and my e39 540i she started to have a slight lose of power and my check engine light started blinking I was doing around 65mphI pulled over cut her off and ran the codes. She gave a miss on 1 and 2 and 5 and a random along with LDP low pressure peak reader from you guys now she will not start; when you turn the key it just cranks and you can hear the starter and flywheel spinning I just replace left and right side cam sensors
with no change can it be the crank seneor?
December 21, 2016
  Followup from the Pelican Staff: I can't help without knowing what is missing from the system when you are trying to start it. When your engine doesn’t start you’ll want to check the basics. Check spark, fuel injector pulse and fuel pressure, volume, quality and engine compression. Are there any fault codes? Once you figure out what is missing, it will be easier to diagnose.
- Nick at Pelican Parts
 
charles Comments: got a tip from a friend that my vehicle may need this part replaced. have a 99 528i, fuel pump not working. replaced pump, sending unit and all fuses and relays. friend said that a bad crank sensor may be the issue? any feedback???
December 5, 2016
  Followup from the Pelican Staff: Crank sensor will not kill fuel pump. Look for the relay and test the circuit. - Nick at Pelican Parts  
Ernest Comments: Just to verify, if my E39 6 cylinder with a 12/97 build date has a connector on the wire that connects to the crankshaft sensor, I do Not need to install the updated position sensor wire. I only need to replace the wire if it is hard connected to the sensor. Correct?
August 30, 2016
  Followup from the Pelican Staff: I think the update was similar to what you think, however it has been a while and I don't recall the specifics. I do remember a harness for both, but I may be thinking of E36. Give The Pelican Parts parts specialists a call at 1-888-280-7799. They can figure out what part or repair kit you need.
- Nick at Pelican Parts
 
franky00 Comments: My friend changed my headgasket from my bmw 2003 530i and the first time he turned it on it was fine by the second time it turned on made some wierd sounds and turned off what could be wrong?
October 14, 2015
  Followup from the Pelican Staff: Hard to say without hearing the noise. Inspect the drive belt area and mechanical engine timing. - Nick at Pelican Parts  
Steve Comments: PLEASE HELP. I purchased the new Crankshaft sensor, Updated Position wire, and o-ring the other day and am working on the car now. I was able to remove the sensor from the block but it has a wire no connector on rear of sensor that runs way under the Intake manifold somewhere. Do I need to remove the manifold in order to replace all the wiring along with the sensor and o-ring? Working on a 1997 528i L6.
August 4, 2015
  Followup from the Pelican Staff: Most likely. If you are replacing the wiring, you will have to gain access to the main harness under the intake. - Nick at Pelican Parts  
alpaakar Comments: thank you soo much for the feedback its helpful keep up the good work.ali
July 10, 2015
  Followup from the Pelican Staff: No problem. - Nick at Pelican Parts  
mick Comments: Thanks for the help! The bolt on the sensor is tricky to put pack in. After numerous attempts from underneath the car, I removed the cabin filter and was able to reach in and get it to thread. Car worked better starting but camshaft position sensor code came up and car would run fine then die unexplainedly. I started it again and it would run fine and then die again. Tomorrow I'm replacing the camshaft position sensor. I suspect using an oem bosch will clear up the problem. I ordered a chinese knock off from ebay but save your time and money and go with the bosch.
November 25, 2014
  Followup from the Pelican Staff: Thanks for the follow up and sharing your experience
- Nick at Pelican Parts
 
merv Comments: at last a picture and dialog that is idiot proof. Thanks
June 3, 2014
  Followup from the Pelican Staff: Thanks for the feedback. Glad we could help.
- Nick at Pelican Parts
 

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Page last updated: Sun 12/10/2017 02:06:31 AM