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M119 Crankshaft Positioning Sensor - Spacer Washer?

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2.5K views 5 replies 3 participants last post by  wlb50  
#1 ·
As I mentioned a few days ago my SL just died in the driveway (at least it was considerate in that regard). I pushed it into the garage with my E430.

Thanks to this list I have realized that I really need the Star SDS to do a full diagnosis, but if changing the CPS doesn't solve it I will have it flat bedded to my friend's shop across town.

One thing I noticed when researching this - the engine originally had a rubberized spacer washer between the sensor and the bell housing - long gone. I suspect some shop in the distant past just threw it away. And looking at non factory sensors on amazon, many say that they don't come with the spacer but to use the "old one". So it has some importance.

And I am wondering if not having it was a possible cause for the (hopefully) short life of the 2 year old factory sensor I had installed on 2016. Would having the sensor sitting on the bare metal affect anything?

I haven't even verified that the sensor is bad as I will go to the dealer Monday and see if I can order one (a spacer washer - bought the sensor today). I will also check the resistance to the wire connecting it.

But as a rule I think the engineers specify parts for a reason.
 
#2 ·
From memory there are two versions of the CPS, a metal one and a plastic one.

When I removed the plastic CPS from my '93 SL500 some years ago, I do not remember any washer or spacer, unless it was stuck to the bell housing.

The CPS is really only just a coil that produces a "Hall Effect" (same as a speed sensor), so any problems are going to be a shorted turn or an open circuit turn in the coil, or damage its cable or plug.

I suppose a washer or spacer could affect the proximity of the coil to the flywheel??

EDIT: Looking at the part online, a washer or spacer would foul the entry of the fixing bolt.
 
#3 ·
Thanks Red - I have had plastic ones and when I replaced the first one 2 years ago, it was an OEM Bosch unit. I am "hoping" that our high heat (107 degrees) when the symptoms first started somehow managed to damage this unit. The dealer has been great; my VIN on file and they know exactly what should be on the car - will report the findings.
 
#5 · (Edited)
I took it (the CPS) back to the dealer John - too many other symptoms. It's as if the car is possessed and needs an exorcism ;-)

I know life would be so much easier if I had the Star-SDS - but I have ordered a couple of relays and if those don't work will have it flatbedded to my shop.

Windows don't work; radio antenna didn't retract when off (now won't extend)...I think I need a priest for an exorcism ;-)

Funny thing for the 96 - which was a major revision - they got rid of a lot of relays. But the one (of 2) in the back next to the fuel pump relay is a "general relay" (orange) and my parts people also ordered one controlling the windows.

I have a feeling that despite the horrendous symptoms the solution is simple (besides pushing the car off a cliff)

Will keep you all posted.

Update: Oh - they said my CPS didn't require a spacer washer - with my VIN on record they know exactly what my car is **supposed** to have.
 
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