w140 Rear Crank Position Sensor / RnR nightmare
 

Everywhere I've read says this is a 10 to 30 min job. Yeah not on this car. The bolt came out ok but the sensor is in there tighter than a frogs behind.

I goosed er down with WD40 (fresh out of penetrating oil ATM) and got it to TWIST in its cylinder with a screw driver. It wont come out.

I tired to retreat...the car won't start.

Called Roy...he told me, yep, you've got to get it out now. Suggested a couple of things that I can basically characterize as creative applications of heat and force...but it's got to some out...or the trans has to be dropped.

He did say sometimes the end of the sensor swells...and it's a Royal PITA of the First Order.

SO DONT BELIEVE THESE YOUTUBE VIDEOS ALL THE TIME EH!!! (no im not Canadian I just like application of that word sometimes)

But it's got to come out...somehow. My friend had to walk home. I'm making coffee.

So I liked the idea of prying under it with a little screwdriver while I pulled on it...well i snapped off the entire plastic head of it leaving the magnet exposed in the center.

I got some more of the plastic broken off and got the pliers on the magnet...it slid out.

Now I have the last what? five hours in this job and I've got the hardest part ahead of me.

This is a friends car I'm trying to help him out but I cant pay nor do I really want to learn how to do a trans R/R right now.

I got the top part of it broken, the magnet pin out of the center and now I'm about to try out a 2nd gen of a modified set of needle nose vice grips...( I tried to grind "hooks" into them.

BTW this is a 1994 W140 S500. There is almost NO room to get your hands behind the engine. The hose clamps on the false firewall are getting a knuckle and top of hand meat bonanza...and thats thru the Mechnix gloves...

Roy said heat might be my best friend here....I'm thinking he's right. I'm going to get the vac line to the trans up out of the way and see if I cant get some heat on JUST this part from underneath. Either that a pencil torch (dont have one)

To quote one of Adam Sandlers comedy routines...."F me in the goat A"
Adam Sandler - The Goat (Skit) - YouTube
caution on that link....adult language!!!

I want to say I will never attempt this again...but you know how us Benzaholics can be....


I HAVE been considering using some kind of puller, I just need to figure out a bolt big and sharp enough to tear into the inside of the magnet cylinder.

I must have been nuts to get into this... when it didnt come right out I should have called a tow truck. Got half the thing broken and out and the other half stuck in there...I physically cant do it anymore...my forearms are so beat up I doubt I'll be in any condition to work on it in the morning either

which engine has this? A V block?

You are not the only one who experienced this problem. It sounds like Mercedes modified the replacement sensors because, over time, the metal housing on the sensor was bonding with the bell housing. Here is a long string that involved the same problem as yours. M119 Crankshaft Position Sensor R&R - Benzworld.org - Mercedes-Benz Discussion Forum

This guy eventually gave up and took the car to the dealer who was able to get it out by drilling and picking. Some in the above link suggested just knocking the sensor through and picking it out through the vent holes in the bottom of the bell housing. Another suggested that if you knocked the sensor into the bell housing you wouldn't have to pull the transmission completely -- only separate it enough to slide the sensor out between the bell housing and engine.

If you plan to drill it, one poster suggested that you remove the transmission mount bolts and lift the transmission up so that it will cause the engine to move down/forward and will give you more room to access the sensor.

I haven't changed mine but I will definitely be interested in how you finally deal with this problem. Best of luck.

I got most of it out with a dremel tool an a couple of drill bits.

HOWEVER the steel sleeve that was around the original sensor remains and wont allow me to insert the new sensor.

OTHER than dropping the transmission....any suggestions?

Can you find a thread chaser or tap that is large enough to put some threads in the outer sleeve, allowing you to pull it out?

I was thinking of that...I called a machinist today

can you use a easy out.Its a tool that removes broke bolts.in your case you gently hammer it in and screw the whole mess out.I buy mine at Sears.

someone else suggested that and then another cautioned against it, as the hammering in could drive the sleeve into the flywheel...but it's worth a thought

hopefully the machinist buddy of mine will be able to make the best call on how to remove the BASTARD THING!!!

Who the hell thought of putting steel sleeves into aluminum cases anyway????? a little confident the sensor would never have to come out eh?

You and Brian C. oughta get together. Between this and his ordeal with spark plugs on his truck you guys can share some major misery.

Maybe pulling the rear trans crossmember and letting the trans sag will give you a little more room? Sorry to hear of your dilemma. Sometimes bad luck points directly at us.

it's not looking good...I have to go see if I can get a carbide bit for the massive dremel I've borrowed...the stone wheels cut the steel up but break off almost right away!


what do you guys think the "part out" value is around?

how long would it take me to sell the engine / trans / rear end?

I would do the easy-out or tap...

To part out the car. It will be just another can of worms plus the time..-W140 transmission, engine and rear end not worth much. The other stuff will fetch a premium

I'm going to check out my CPS.

Martin

DONT TOUCH IT IF IT'S NOT BROKEN.

It took several days of prying and bending and mangling but I got it out yesterday and the new CPS in.

I had used an industrial dremel with a flex shaft....and several bits of stone and steel to cut and bend and mangle...and my arms were not happy...and if I had a lift or the car on level ground at least...well yeah I guess this was better than pulling the engine and trans. What a conundrum with this car...it needs more than it's value in parts and work. It's a shame really.

I went out the car early in the morning, it had been cold (for FL) that night and everything was still covered in dew. I reached in with my needlenoses and it came right out.

Car still runs like crap. It hasn't had a fuel filter or any maintenance other than oil changes in over 4 years. Owner wants to dump it, didnt want to part with the $20 for the fuel filter, drove it home yesterday.

BASTARD OF A THING...NOT FUN AT ALL.

http://imageshack.us/a/img339/374/cpssteel002.jpg

oh and I felt the middle finger was appropriate for whoever decided to put a steel sleeve around the nylon sensor...which goes into the ALUMINUM bell housing!!!!

http://imageshack.us/a/img585/4547/cpssteel003.jpg