I replaced my crankshaft position sensor yesterday and noticed something strange: the new one I installed had what looked like two collars on its shaft for a rubber o-ring seal, but there was no seal. But then i took the old sensor off and noticed it has the same configuration but no seal, and it was an OEM (and possibly original) FoMoCo sensor... So my question is, should the sensor have an o-ring seal or not? A deeper search on the internet of various manufacturers of the sensor show that some had o-rings and some didnt; but if the OEM factory original sensor did not have an o-ring then I guess I'll go with no o-ring....

 

Since the service manual doesn't say anything about this, unless you get a definitive answer here you should call the supplier who sold it to you and ask.

 

It's probably used in multiple applications, some of which have more exposure to oil than others (such as camshafts). If the old one didn't have o-rings and wasn't leaking it should be fine.

If you look at the shop manual, the sensor reads off the flywheel/flexplate. Since that is outside the main oil seal, there shouldn't be any oil there or need for o-rings.

 

My $0.02, the o-ring can't be a bad thing but yes, calling the supplier is the way to go.

 

well. when my crankshaft position sensor thru a fault... it was a fault. So yes, its replaced. It came with the new engine.

 

I agree, it probably couldn't hurt to use the o-ring. But since the original sensor didnt have one then I left it off on the new one.

Just a side note on the sensor for future DIY: I'd searched the internet to find how/where info on sensor replacement and found next to nothing. So for future LR2 diy'ers: the crankshaft position sensor on a 3.2 is located on the front (grille/headlight) side of the engine, halfway down; below the fuel rail pressure sensor, to the right of the throttle body. To replace it you have to jack the car up (if poor like me and don't have the luxury of a lift), and snake your arm up from the bottom with a torx tool to replace it. If you stick a flashlight up from the bottom you can just barely see it enough to figure out how to twist your arm like a corkscrew to get to it. It's kind of hard to get to but definately able to be done.

 

For future reference...

You can of course buy a variety pack of orings and find one that fits, or go pick one out at FLAPS or Home Despot, if you prefer. Looking at the manual I don't think an oring would hurt anything. Even if it got loose the flex plate and starter are waaay tougher than any oring.