Crankshaft Position Sensor Stuck/Broken Off On Removal Attempt

[cutlassman]

Uh oh. In an attempt to replace the crankshaft position sensor on my 1992 Cutlass Supreme 3.1L, the original sensor has disintegrated and become stuck in the block. There’s a little bit of the original plug left, but I can’t get the sensor to pop out. Any suggestions?

[55trucker]

ooooops.

How much of the original shoulder (butts up against the wall of the block) of the sensor is left?

[cutlassman]

[cutlassman]

The pins are still sticking out. 

[55trucker]

Hard to tell if the shoulder is still partially there from that photo angle.

One would try to get a thin prybar between the shoulder & the block wall to attempt to shift it free.

There is a neoprene O ring around the sensor body, that could be holding it in place.

[cutlassman]

The shoulder has pretty much chipped away. Is the o-ring the only thing holding it in? Should it pop out no matter which way it’s turned?

[55trucker]

The dia of the sensor body would allow the sensor to slide in & out without effort, it's the O-ring that would hold it in place. As long as one can get a grip on what's left to rotate it back & forth it will release.

[White93z34]

ho boy, have fun with that.

Been there a couple times. what usually happens is the sensor gets a crack and gets oil into it swelling the housing.

I've drilled into the back of them and used a wood screw and a small pair of vice grips to rip it out,

Its a total nightmare.

[cutlassman]

Oh man, I’m afraid of that. I’ll try to get a screw into it and rip it out. I guess the only other option is to drop the oil pan and go at it from the inside? That’s a job. 

[White93z34]

thats one way, to me its a last resort.

I've used a dremel with drill bits chucked in it, picks, and pretty much any implement you can think to get purchase into the body of the thing, its miserable.

Once you get the surely hard as a rock o ring out of the hole you remove one of the major things that will hold you up 

[cutlassman]

Ok, thanks, I really appreciate your advice and experience with this!

[55trucker]

You might consider a 40" flexible extension that chucks into a power drill to get a drill bit at the sensor body. Seeing as the easiest position to get at the sensor is thru the passenger side wheel opening (if you try from under the car the trans is literally in the way) one needs a small device to get in there to work with. 

[White93z34]

Its fairly accessible on a 3.1/2.8 if you pull the alternator and bracket and go that way

[cutlassman]

Thanks to you both for the info. I’ll tackle this as I have time and will post an update. Wish me luck!

[cutlassman]

I’ve owned this car for almost 24 years and getting that broken crankshaft position sensor out was probably the biggest PITA since! I was able to get various drill bit sizes into the hole and chip away at the plastic sensor. Unfortunately, when it finally started to loosen, I accidentally pushed the sensor into the block where I could hear it thud into the oil pan. New problem now! After draining the oil, I tried to fish it out through the oil pan drain hole with no luck. The metal middle of sensor is in there, along with about 75% of the plastic surround. Dropping the oil pan is such a hassle, so I may just leave the sensor remains in there and roll the dice. Or, I thought about drilling a 3” hole in the oil pan and then patching it. Anybody have any experience doing anything like that? I haven’t found a suitable plug, yet. So frustrating. 

[jiggity76]

6 hours ago, cutlassman said:

I’ve owned this car for almost 24 years and getting that broken crankshaft position sensor out was probably the biggest PITA since! I was able to get various drill bit sizes into the hole and chip away at the plastic sensor. Unfortunately, when it finally started to loosen, I accidentally pushed the sensor into the block where I could hear it thud into the oil pan. New problem now! After draining the oil, I tried to fish it out through the oil pan drain hole with no luck. The metal middle of sensor is in there, along with about 75% of the plastic surround. Dropping the oil pan is such a hassle, so I may just leave the sensor remains in there and roll the dice. Or, I thought about drilling a 3” hole in the oil pan and then patching it. Anybody have any experience doing anything like that? I haven’t found a suitable plug, yet. So frustrating. 

I feel your pain but if it were my car, I would just drop the pan.  I haven't done this on a 3.1 car as I own LQ1 cars but it's not a bad job really.  Just make sure to clean everything well and you might as well put a new gasket on it.  There are instructions in my manuals that require torque for the gasket and the metal tabs in certain areas of the perimeter of the pan flange.  You'll also want to add dabs of silicone sealant in the corners of the pan where it goes up and around the crankshaft, etc.  Again, the manual recommends this.

[Bake82]

If it's financially feasible, this may be a good opportunity to drop the pan and have easy access to the steering rack, motor/trans mounts, power steering lines and replace those as well if there is any sign of failure.  

 

I would only patch the oil pan if it'd welded shut.  Not sure how good of a weld you could get on the oil pan with it on the car and not being able to clean the oil pan super well.  

 

 

[rich_e777]

Bite the bullet and pull the pan off, with a engine bay support bar its not really that hard. Replace the oil pump with a newer higher volume one while your at it. Your timing cover gasket is probably in need of replacement as well so you might as well make it a good project.

[cutlassman]

I appreciate all the advice. I’ll bite the bullet and drop the pan. The engine support bar is a great idea. A new oil pump makes sense and the power steering lines are leaking a bit, so I’ll knock those out, too. Might as well check out everything else while I’m in there. 

[Bake82]

21 hours ago, cutlassman said:

I appreciate all the advice. I’ll bite the bullet and drop the pan. The engine support bar is a great idea. A new oil pump makes sense and the power steering lines are leaking a bit, so I’ll knock those out, too. Might as well check out everything else while I’m in there. 

Good idea!  It sucks for sure, but sounds like there will be a few things to do that will be easier with the subframe out of the way.  

 

100% get an engine support bar or make one, It'll be way better.  I did one with an engine hoist one time, and it was just a pain in the rear because the hoist legs were just in the way! 

[cutlassman]

I have an engine support bar ordered to try to make things as easy as possible. I’m adding subframe bushings to the project, too, along with a new trans pan gasket and filter swap. I don’t need to drive the car so I might as well do as much as I can!

[cutlassman]

Well…that wasn’t fun. The engine support bar is a must. I had to replace the rear subframe mounts since the originals were rusted out. The Dorman replacements are a PITA to install since there’s really no slack in the original bolts, which had to be reused. The old crankshaft position sensor that was broken off was in the top of the pan. I replaced leaking power steering hoses in the process and cleaned up oily wiring and added new split-sleeve wire protectors. The car fired up right away after I had everything reinstalled - definitely a sigh of relief! I lowered the entire subframe to get the oil pan out…replaced the engine and transmission mounts while I had the chance. Definitely use a lubricant and take it slow if you have to remove a crankshaft position sensor. 

[jiggity76]

Nice work.  I'll be dropping the drivetrain out of the International again at some point either later this year or next.  Needs a tranny rebuild, new steering rack, new power steering lines, and mounts.  Whatever else she might need when it's all opened up.  I learned so much with this car that I'm going to apply the process to the STE here pretty soon and make it easier on myself.

[cutlassman]

Same here, having owned my ‘92 for 24 years now, there’s a lot I’ve learned! 

[jiggity76]

21 minutes ago, cutlassman said:

Same here, having owned my ‘92 for 24 years now, there’s a lot I’ve learned! 

I'm still learning things almost daily about these cars.  With me going this in depth for my car restorations, it has forced me to learn how these cars are put together and the proper and correct ways of doing repairs, etc.