2002 8.1l V8 Crankshaft Position Sensor

[tjg79]

Scan code indicates a problem with the crankshaft position sensor. I've had two incidents of cranks but fails to start after a short trip, but started ok several hours later.

 

Is the crankshaft position sensor reasonably easy to replace? Dealer wants $400.00 for the task. I can get the sensor for $62 (shipping included) from GMPartsDirect.

 

I don't have my GM shop manuals with me at the moment, so any advice from someone who's been there, done that would be appreciated.

 

Regards to all.

[VRSCA1]

 

1. 
   <LI type=1>Raise and suitably support the vehicle. Refer to

Lifting and Jacking the Vehicle in General Information. <LI type=1>Remove the fuel line bracket nut (5). <LI type=1>Remove the fuel line bracket from the bellhousing stud. <LI type=1>Lower the vehicle.


<LI type=1>Remove the driver side rear ignition coil bolts. <LI type=1>Reposition the coil. <LI type=1>Disconnect the crankshaft position (CKP) sensor electrical connector. <LI type=1>Use penetrating oil and allow the oil to soak around the CKP sensor prior to removing the sensor.


<LI type=1>Remove the CKP sensor bolt. <LI type=1>Prior to removal of the CKP sensor, twist the sensor back and forth. <LI type=1>Remove the CKP sensor.


<LI type=1>Inspect the CKP sensor for wear. Important: The CKP sensor is designed to contact the reluctor wheel of the crankshaft. Wear may be noticeable on the end of the sensor.
 
<LI type=1>Normal CKP sensor wear will be shown on the wear strips (1), and no wear will be shown on the sensor sensing element (2).


<LI type=1>Excessive or abnormal sensor wear will be shown on the sensing element (2).
If excessive/abnormal wear is present, replace the sensor.

<A href="http://gsi.xw.gm.com/si/cellHandler.do?cellId=62527&refDoc=803001&from=sm#ss2-682027">

Installation Procedure

 

1. 
   
   

<LI type=1>If reusing the old sensor, Inspect the O-rings for cuts, cracks, tears or damage, replace as needed. <LI type=1>Lubricate the CKP sensor O-rings with clean engine oil. Important: Ensure that the CKP sensor is fully seated against the crankshaft reluctor ring. The upper flange on the sensor MAY NOT seat against the engine block.
 
<LI type=1>Install the CKP sensor. Important: The CKP sensor bolt has adhesive applied to the threads. The adhesive may have come off during removal of the bolt. Ensure that the bolt hole is clean of any debris before installing the reinstalling bolt.
 
<LI type=1>If reusing the old sensor, apply thread adhesive GM P/N United States 12345493, GM P/N Canada 10953488, or equivalent to the bolt threads. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
 
<LI type=1>Install the CKP sensor bolt. Tighten
Tighten the bolt to 12 N·m (106 lb in).
 
 


<LI type=1>Connect the CKP sensor electrical connector. <LI type=1>Position the coil to the rocker cover. <LI type=1>Install the driver side rear ignition coil bolts. Tighten
Tighten the bolts to 12 N·m (106 lb in).
 
 


<LI type=1>Raise the vehicle. <LI type=1>Install the fuel line bracket to the bellhousing stud. <LI type=1>Install the fuel line bracket nut (5). <LI type=1>Lower the vehicle.
Perform the CKP system variation learn procedure. Refer to Crankshaft Position System Variation Learn .

 

[VRSCA1]

Scan code indicates a problem with the crankshaft position sensor. I've had two incidents of cranks but fails to start after a short trip, but started ok several hours later.

 

Is the crankshaft position sensor reasonably easy to replace? Dealer wants $400.00 for the task. I can get the sensor for $62 (shipping included) from GMPartsDirect.

 

I don't have my GM shop manuals with me at the moment, so any advice from someone who's been there, done that would be appreciated.

 

Regards to all.

 

Here you go,I have done a few back in the day seen a couple CKP sensors cause issues.

Not to bad to change out need to squeeze your hands into the bell housing area on the left side between the bulkhead and cylinder head area.

Make sure you do not have excessive crankshaft endplay this is rare,Also Load test the CKP circuits back to the controller.Check for spread terminals,wire rub throughs also.

It states you need to perform a CKP variation relearn using the scan tool but I think you can get away without doing it,usually this was required only if the crankshaft was replaced or the controller was replaced.

[tjg79]

Thanks VRSCA1!

 

Your post answers my question completely.

 

How do you check for excessive crankshaft endplay without disassembling the engine?

 

Regards

[VRSCA1]

Thanks VRSCA1!

 

Your post answers my question completely.

 

How do you check for excessive crankshaft endplay without disassembling the engine?

 

Regards

 

Take the belt off,it should be checked using a dial indicator gauge and there is a spec but for all intensive purposes,just grab the crank pulley and make sure it does not move back and fourth it should tight with no movement,it would need to move quite a bit to set the fault,like I said rare but possible,it would be obvious if it moved a great deal.

[tjg79]

Thanks VRSCA1!

 

Your post answers my question completely.

 

How do you check for excessive crankshaft endplay without disassembling the engine?

 

Regards

 

Take the belt off,it should be checked using a dial indicator gauge and there is a spec but for all intensive purposes,just grab the crank pulley and make sure it does not move back and fourth it should tight with no movement,it would need to move quite a bit to set the fault,like I said rare but possible,it would be obvious if it moved a great deal.

 

 

Thanks again for the poop. The check for excessive crankshaft endplay is not as involved as I first imagined.

 

Regards