Crank Shaft Position Sensor Problems

chevrolet
tahoe
sensors

#1

I have a 1996 Chevy Tahoe V-8 5.7 with 154000 miles on it and with a crank shaft position sensor problems. I have put 2 sensors in the truck and replaced the fuel filter and fuel pump. I put a new sensor in and it runs fine for a couple weeks, then it starts acting up again. The computer says it is the sensor failing again, but I got to believe it has to be something else after nearly $1000 worth of maintenance and still the same problems. I would like to keep the truck until 200,000 miles, but I am about ready to shot it.


#2

It would be good to know what code you are getting for this problem. If it is a circuit error code then the trouble is with the wiring to the sensor.


#3

Make sure your balancer is not coming apart. If the rubber starts to separate, that can throw the crank sensor off or kill them.


#4

Computer Error Code 51 and the we thought there was a short in the wiring and have checked all the wiring and it seems to be okay.


#5

How will I know it is the Crank Balancer failing? Replacing it will require tearing apart the front of the engine, if I understand what you are talking about. You would think this problem would happen ever time I drive the truck, but sometimes it will drive fine all day and then the next day will not drive correctly at all.


#6

I too recently went through several months fighting with my 1996 Tahoe with check engine light and rough running and failure to start. After several months of investigation and several sensors replaced and several thousands of dollars spent on probably unnecessary repairs, I discovered with the help of a good mechanic that one of the wires on the top crank sensor even though is showed good connectivity had the insulation melted off the wire due to the engine heat exhaust too close to the wire. The wire was covered by an aluminum shield and the wire would periodically short out on the aluminum fooling the engine computer into thinking something was wrong with the engine. Because the wire is inside this aluminum shielding it is hard to detect without removing it that this is really the problem. Several mechanics worked on it and replaced both the top and bottom sensors and several other things before we discovered the wiring problem.


#7

Reminds me of 35 years ago a 21" B&W TV (wooden cabinet hernia maker) had a short in the shielded cable to the horizontal hold control on the front panel.
3 good techs spent many hours grappling with that until somebody noticed the control itself had very little effect on the horiz frequency.