car: 1987 300E

I have the CPS, and have traced it from the EZL back to the bellhousing. The only problem is that it is in a pretty inaccessible area of the car. I can just about get the ratchet and hex-head into the space under the oil filter. How can I go about getting the CPS out, and is there anything special that should be done when installing the new one? I noticed quite a bit of grease all over that area, care of the oil filter. Once the new one is in, is it just a matter of cranking it in and everything should work, or is there any adjustment that needs to be made (some other posts have referenced adjusting the CPS)?

Thanks for your help.

John

__________________
87 300E
202k on the clock

Are you working from above or below? It's just tight. Sometimes it helps to custom make a tool for the job.

above i guess, if i need to be below, i can do that too, just have to pop the car in neutral and roll it into the garage.

what would you suggest for a custom tool? I have the hex heads, 3 mm i believe is what fits from last night. Should I think about draining the oil and removing the filter (needs to be changed anyways)? Only problem there is it opens a whole new can of worms being that my drain bolt is almost stripped - thanks to whoever did the last oil change w/ an impact gun or a 4 ft wrench (previous owners).

i guess what i am really looking for is any kind of pointers to get access to the cps, because my efforts last night were in vain.

thanks again.

john

__________________
87 300E
202k on the clock

You need to get underneath and see what you've got - what size and how much room. 3mm sounds a bit small. You may need to cut off an allen wrench. It seems to me like Sears sells some low profile allen wrenches of some sort - not sure about that. Or you could cut off an allen wrench, drive the piece into a nut and put the nut in a swivel head, racheting box wrench. You just need to improvise based on how much room you have.

If the CPS is on the bell housing in the rear of the engine, what is the sensor at the front of the engine by the crank pulley on the left side (USA)? On the '90 and '91 103s, anyway.

__________________
2012 E350
2006 Callaway SC560

That's the CPS too. Strangely there's two parts on these cars commonly referred to as the crankshaft position sensor. The one of the front is also known as the TDC reference sensor. I believe it connects to the wiring harness. The one in the rear goes from the bell housing to the EZL. The latter is the more expensive and the harder to get to.

correct, the one at the bell housing is hard to get too - so hard that when I could not remove it myself, I sent the car to the mechanic - hopefully he can finish the job.

Question though: The TDC sensor, when I traced that back from the block, I noticed it went to the X11 port on the side wall - does that mean it deals only w/ diagnostics, or does it route elsewhere after that?

__________________
87 300E
202k on the clock

The top dead center sensor rally only deals with the x11 diagnostic plug. it is used to get info on the crank position during diagnostics only as far as I can tell. My 1986 has it and it is only diagnostic and only connected to the x11 plug. I replaced it when I did the fan belt tensioner and learned it does nothing, I need the rear sensor instead. Top dead center sensor = $45 Crankshaft position sensor (rear) = $160

__________________
Christopher Henkel
1990 190E 2.6 - Arctic white SOLD
1986 190E-16v - Blauswartze
1993 300CE - SOLD
2003 W208 CLK 320 Cabriolet - Magma Red

I see this is an older thread, but I'll give a couple of suggestions as I had just changed my CPS.

Here is where I purchased my CPS from. Not cheap, but not $160.00 either.

http://catalog.worldpac.com/tayco/quote.jsp?clientid=alloemautoparts.com&cookieid=28F0MRM8B28F0MRQH2&baseurl=http://www.alloemautoparts.com/&partner=tayco&year=1987&product=F6010-12107&application=000006816

Go ahead and remove the oil filter. You don't have to change the oil to do that. It gives you that added little bit of vision that you need to do the job. Also, make sure your hood is ALL the way up to the vertical position. This will give you better access. The CPS is changed from the top, I do not see any way to do it from the bottom. It is a 5mm (if my short term memory serves me) I used an allen bit in a socket and a 3 inch extension. It was mildly difficult for me, but I wrench for a living, albeit on airplanes.

After you have it out, clean up the area using a solvent (brake cleaner or the likes) There is no adjustment on the sensor. It just sends a signal from the poles on the flywheel to the 'computer' to let it know the engine is turning. I believe that my original sensor (195K) went to an open ohm reading when it got hot. It would start after a while. Put the new sensor in and make sure it is tightened flush.

Just my limited experience on this.

Sam

__________________
1987 300E
1972 220d
2004 Dodge Ram 2500 T/D
1997 Explorer
1999 F250 V10 Guzzler
2002 Honda VTX 1800

2003 Boxer Named Sir Lancelot (Lance)

You could do your car from the bottom, of course have to get it off the ground a bit. Some of the newer more crowded engine bays can only be done from the bottom.