LS400 1991 Crank sensor stuck

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Hi all.


Need a little help.


It died on me last week. The flashy lights blinked a code 12, meaning a no rpm signal.

Suggesting a Crank Sensor replacement.

I am trying to get it out, its on the underside.

Problem is, it came up about 1 mm, then stopped and things broke off.

I am guessing I am not the first one having problems getting a 25 year old sensor out.

Is there a way to get it out by drilling ? Does the hole have a bottom ?

If not, when I drill it out, will stuff go in the hole and cause problems ?





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Can you take a pic of the remaining sensor and post so we can see what you are up against?

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Here is the culprit. By the way, it is out. It was so darn stuck in there I had to drill it out. 


The new one is in we're running again.








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Lots of corrosion, did you lube it up a bit before installing the new one? How far did you drill into it and what size drill, then what a nice wood or sheet metal screw or what? Also looks like a lot of RTV or something there?????

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Well, I have been having trouble, because the location was not really accessible for me. I decided to invest in some tools. firstly, a garagejack that could lift the whole front, so there was room to work.  I have tried putting a screw in there, and then I had nothing to grab on to except for some grip pliers. After that I tried putting a hook in that screwed into the same hole, and getting some piece of rope and a tire iron to get some leverage against the support strut that is right under there. I bent the hook out of shape so it was really stuck in there.

After that I got my trusty  rechargeable drill with a 5 mm. bit that was very new and sharp, and started drilling from the hole the screw made, and try to ease away the material, nice and slow. The dril can go very slow, so that helped. I tried to get the upper edge because that was glued to the hole. when that was done, the whole thing came loose and it dropped out by itself. 

When I checked the hole, some green residue suggests to me that it is probably a cooling leak that dripped down there, and started eating away at stuff.

The drill did not damage the aluminum of the engine block. I also noticed that the hole is in fact big enough for the sensor not to touch the sides of the hole, so maybe I should get rid of the coolant leak to prevent things from being destroyed again.

I put in the bolt that holds the sensor in, put the connector on and fired up the engine. It runs very smooth.

I also noticed that my battery was down a bit from standing still for a while, so I did a test drive to get things charged up again.

Now when I do a warm start, instead of having to make 7 or 8 rotations of the crankshaft before it starts, it needs 1 or 2 rotations., so that's an improvement.

I hope this can help someone in the future.



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I would have put a thin film of Vaseline or grease on it and in the hole so it wouldn't corrode again. Good work getting it out of there.

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