496 Crankshaft Position Sensor stuck
 

Looking for some advice. 2006 496HO. I'm replacing the Crank Position Sensor and it is very much stuck. I've tried just about everything to pull or twist it out and it is on the verge of breaking the top off, so I backed off the project and decided to sleep on it before going back to it. Does anybody have any recommendations to coax it out of there without breaking the top of it off, which I think would make things much worse.

thanks.

try getting some transmission fluid in,under the lip to try an break free the o-ring.other trick is to pry evenly w/ 2 small pry bars.if the top breaks off,well them you can easily soak the o-ring and slide hammer the thing out.o-rings can really stick after years of sitting.

Thanks. It definitely is worth a try. Yeah, the thing is really stuck plus, I am in a saltwater environment and I'm sure that has something to do with it sticking.

Yes that is correct as saltwater atmosphere sticking the crank pos sensor and even at times fresh water apps that an engine compartment stays wet will get it stuck as well.

Anyways mix some acetone and transmission fluid together, let it sit for awhile but keeping using the mix thru out. Try to see if that loosens it up.

If not keep using the mix and add a hair dryer to heat the area up, see if you are able to pull it out then.

This is how I have done it for years but with that said hopefully you did not already weaken the pencil portion of the crank pos sensor enough to have it break off completely.

try PB blaster soaking it, but may have to pull the cover, and thats not a easy deal either

One that my father used to use was tranny fluid and diesel mixed together, that stuff would creep through anything.

Remove the aft starboard spark plug, and via an adapter, attach the air line from your compressor. Crank that bltch up to around 215 psi and stand back. It will come out.
:D :D

In all seriousness, are you getting a good hold on it? I had a bear of of time getting one of mine out. It fractured on the way out, but did not break. There is a thermistor or something just above it; about the size of a large spool of thread. It comes out of the way relatively easily. Once I pulled that out of the way, I was able to rotate the CrankPOS about 100* back and forth, and it came out as I tugged on it. Get a thick moving blanket and lay across the top of your motors, and get a good hold of it. If it is your port motor, perhaps you can reach it from a tall ladder from outside the boat as well.

Thank you for the replies. It is on my Starboard motor and I have a pretty good grip on it by laying across my motor. I was able to rotate it, but I'm afraid that caused it to start breaking. That plastic is very brittle. I soaked it down with PB blaster and I'm going to let it sit for a few days while I am out of town and hopefully that will loosen it up.

forgot to say - if you can buy the older cans of Merc Power Tune - that works well for freeing up this as well. The newest Merc power tune is very weak (EPA mandated formula) is not as strong nor does the job like it use to.

I would try carb cleaner as well. I have had that work for me a few times.

Thanks Sydwayz and Bup for the ideas. I'm off-island right now and in the Mainland. My trip was extended by two more weeks, so I'm hoping the PB blaster applied will have plenty of time to free it up. Oh, yeah....and it did break off and it is flush with the engine block. A quick internet search on this topic resulted in a ton of similar situations with a variety of motors, to include the Chevy 8.1 truck motor. The most successful stories of removal involved a screw and better leverage to pull it out. So, when I get back, I'm going to drive a sheet metal screw right down the middle of the plastic portion creating something to grab onto then try to pull it out.