The YouTube video below gives a good overview of what needs to be done to replace the Crankshaft Position Sensor on a 3800 Buick V6 engine used in the Buick Reatta. The video also gives a good description of how the sensor works.
These Reatta specific details should be noted as you view the video.
1. The puller shown in the video may not be needed for 1988-1990 Reatta engines. The harmonic balancer on those engines shouldn't be a press fit. The 1991 Reatta engine does have a press fit on the harmonic balancer requiring a puller to remove it.
2. The splash panel on the Reatta is different from the one shown in the video.
3. The harmonic balancer bolt on my '88 Reatta requires a 1-1/8" socket. Some bolts require a 15/16" socket. Here is a link to using the starter to break the harmonic balancer bolt loose. Harmonic Balancer Bolt Removal
4. You probably won't see the plastic cover over the sensor as described in the video.
5. The video describes a different way of tightening the harmonic balancer bolt to the proper torque than the Reatta FSM does. The bolt needs to be torqued to 219 lbs. ft. according to the service manual. (1991 models might have a different torque spec.)
