Parts Catalog Accessories Catalog Tech Info Tech Forums
 
Follow Pelican Parts on Facebook Follow Pelican Parts on Twitter Follow Pelican Parts on Instagram Follow Pelican Parts on YouTube Follow Pelican Parts on Pinterest Follow Pelican Parts on Tumblr
  Search our site:    
View Recent Cars  |   Cart  | Project List | Order Status | Help    
 >  >
Crankshaft Sensor Replacement
 
Bookmark and Share

Pelican Technical Article:

Crankshaft Sensor Replacement

Nick Czerula

Time:

3 hours3 hrs

Tab:

$50

Talent:

*****

Tools:

Set of sockets, 5mm Allen bit, flathead screwdriver

Applicable Models:

BMW Z3 (1996-02)

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 digital motor electronics (DME) engine management system in BMW Z3 vehicles receives input signals from a variety of sensors in order to meter fuel and regulate ignition timing. The most important sensors are as follows:

  • Mass air flow (MAF) sensor ahead of the air filter housing detect the mass and temperature of air entering the intake.
  • Engine coolant temperature (ECT) sensor detects coolant temperature at the cylinder head.
  • Crankshaft position (CKP) sensor detects crankshaft TDC position.
  • Camshaft position (CMP) sensor(s) detect cylinder firing position as well as camshaft timing advance or retard.
  • Engine knock sensor(s) detect pre-ignition or detonation.
  • Oxygen sensors detect oxygen content (and therefore engine combustion efficiency) in the exhaust stream.
  • Radiator outlet hose coolant temperature sensor detect the temperature of coolant leaving the bottom of the radiator.

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 the 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 please 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 4-cylinder models you can access the sensor from above on the left side. On 6-cylinder models, you can access sensor from below the vehicle, working on the left side. 

To avoid marring the paint and trim, work with a plastic prying tool or wrap a screwdriver tip with masking tape before prying out body or interior items.

Keep in mind that when your car was serviced before, parts may have been replaced with different size fasteners used in the replacement. The sizes of the nuts and bolts we give may be different from what you have, so be prepared with different size sockets and wrenches. 

Do not open the coolant reservoir cap or disconnect any coolant hoses or other components until the engine is completely cooled off. Hot coolant scalds.

When performing electrical tests, be sure to use a digital instrument such as DVOM. Using an analog device may lead to damage to sensitive electronic components.

Protect your eyes, hands and body from fluids, dust and debris while working on your vehicle. If you're working with the electrical system, disconnect the battery before beginning. Always catch fluids in appropriate containers and properly dispose of any fluid waste. Recycle parts, packaging and fluids when possible. Do not work on your vehicle if you feel the task is beyond your ability. 

Vehicle models change and evolve, as they grow older, so the vehicle shown in our illustrations may vary slightly from yours. If something seems different, let us know and share your info to help other users. Do you have questions or want to add to the article? Leave a comment below. When leaving a comment, please leave your vehicle information.

Models with 4-cylinder engine
The crankshaft sensor is located below the starter motor.
Figure 1

The crankshaft sensor is located below the starter motor. You can see it if you look past the engine oil dipstick tube, It is mounted in the engine crankcase (green arrow).

Remove the upper intake manifold. See our tech article on intake manifold removing.

The camshaft sensor electrical connector is the rear mounted connector at the electrical junction, the electrical junction is in the center of the lower intake manifold, and accessible once upper intake manifold is removed.
Figure 2

The camshaft sensor electrical connector is the rear mounted connector at the electrical junction, the electrical junction is in the center of the lower intake manifold, and accessible once upper intake manifold is removed. To disconnect it, press the wire release tab (green arrow), then pull the connector straight out to remove.

Once the electrical connector is disconnected, pull the wiring harness out of the small mounting clip on the crankcase.
Figure 3

Once the electrical connector is disconnected, pull the wiring harness out of the small mounting clip on the crankcase. The mounting clip (green arrow) is located a few centimeters forward of the starter motor (purple arrow). The crankshaft sensor wire will pull out as you hold the clip open.

Next, using a 5mm Allen bit, remove crankshaft sensor mounting fastener.
Figure 4

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 4" extension on my 1/4 drive ratchet.

Once Allen bolt is removed, pull crankshaft out of engine block.
Figure 5

Once Allen bolt is removed, pull crankshaft 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. (green arrow)

Install new sensor and sealing O-ring. Torque sensor to engine block 10Nm (7 ft-lb). Reroute and reconnect electrical connector, then reassemble upper intake manifold. Start vehicle and allow 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 6-cylinder engine
Working below starter motor (yellow arrow) at left side of engine, disconnect crankshaft sensor electrical connector.
Figure 6

Raise and support front of vehicle safely. See our tech article on vehicle jacking. 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 7

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 1" extension on my 1/4 drive ratchet.

Once Allen bolt is removed, pull crankshaft out of engine block.
Figure 8

Once Allen bolt is removed, pull crankshaft 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 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.













Bookmark and Share

  Search our site:    

View Cart & CheckOut | Project List | Order Status |  Help    

 

[Home] [Customer Service] [Shopping Cart] [Privacy Statement]
 [Contact Us] [About Us] [Shipping] [Map to our Location] [Careers]

Copyright © Pelican Parts Inc.

Page last updated: Sat 12/3/2016 03:09:26 AM