Date registered: Oct 2007
Vehicle: '99 CLK 320 Coupe
Location: Santa Barbara, CA
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Replacing the Crank Position Sensor (using a dab of Superglue on the bolt!)
Last night, after receiving a somewhat frantic call from a female friend, I had the "pleasure" of replacing the CPS on her '01 CLK 430 using the above helpful information. Thanks to all the forum folks who posted above. I have to add that doing this at night in Los Angeles, in the less-than-friendly confines of a gas station parking lot was not my idea, but when cars breakdown and friends call, you don't have much choice.
I have a '99 CLK 320 and looked at my V6 to get an idea of what is needed to do the R&R. The location of the sensor makes getting your hand in there with a socket a challenge. My biggest concern was dropping the small screw into the engine compartment and losing it. Through trial and error and a limited access to tools, I settled on a 6.0mm 1/4" drive six-point socket, 3" & 6" 1/4" extensions, 1/4" universal joint, 1/4 to 3/8 adapter and 3/8 ratchet. I also used a really bright LED flashlight and a 1x3" inspection mirror to help locate and line up the socket to the bolt.
On the 430 luckily the electrical connection has a single "push to release" connector, so that came off first with little fuss. (my 320 has a more difficult two point release). Next I fished the 6.0mm socket onto the star-headed bolt, with the 3' + 6" 1/4" extensions attached to the socket. Once I felt the socket land on the bolt, I attached the universal joint, 3/8 adapter and ratchet to loosen the bolt. It only takes a quarter turn to make it loose, which then made removing the bolt a one-handed operation. I tried putting some ABC gum on the socket which kept the bolt from falling off. There's very little wiggle room because of the heat shield that nearly blocks access to the bolt so this is trickier than it might appear at first.
Out came the old sensor and in went the new one. I then used SUPERGLUE to attach the bolt to the socket. Might be overkill, but I was not looking to spend a night in LA if I didn't have to and the tape or grease methods didn't seem as foolproof for me. I was miles from home and if that bolt got lost at 10pm, I was not going to be really happy.
Getting the bolt lined up with the sensor and the threaded hole in the back of the engine took a few minutes since there isn't a detent or flange to help locate it. But once it was in and tight, the superglued socket came off of the bolt easily. The electrical connector replugged with a definitive click and all was good. The engine started and the problem was solved.
The intermittent engine stalling on the car should have been dealt with as soon as it started a few weeks earlier, so as a word of caution to anyone with that problem, I'd highly recommend getting the sensor ($54 at Autozone or Oreilly's or a bit less at Autohauz.com and do the swap in the comfort of your own garage. I found the 1/4" extensions, U-joint and a $9.99 socket set that included the 6.0mm 1/4" socket at my corner auto parts store. I didn't have the time to fiddle with my 3/8" drive star sockets and with so little room, I took the above poster's advice and went with the 1/4" tools.
I have a cheapie OBD-II scanner, but for some reason it doesn't work on the '01, just on my "99, so I wasn't able to read what the error codes were, but the car now runs fine and by disconnecting the battery to do an Okie code reset, the Check Engine light has gone out after the engine starts.
Thanks again to the many helpful posters in this forum. You've saved me countless dollars and hours of trial and error on a host of minor issues and maintenance. My '99 CLK 320, now with 104k on it, has been extremely reliable and trouble-free, fingers crossed, it will stay that way.
Last edited by jvfante; 08-06-2012 at 04:51 PM.