I have a 2005 M.Benz C240, I have an oil leak, good amount showing up on the floor every day. It looks like it's coming from the rear part of the motor, sort of like in front of the radio, center of vehicle, if you were to measure from the radiator back, I would say 3 ft. from the radiator. I have yet to put it on my ramps, I will say that when I did my oil change I didn't have much room to slide under the car, meaning if I drive it up the ramps, remove the skid plastic plates, I don't know if I will be able to sneak under enough to see where the oil is coming from. Any suggestions, ideas, experiences? I'm hoping an oil sending unit, sensor that has cracked that is leaking oil. Please don't say say, REAR MAIN SEAL, PLEASE!! Thanks
Ant

with it on ramps you should be able to see where its comming from

hopefully its the oil level sensor

can I get to the oil level sensor from up top or does it need to be changed from below? that is if I can find itThanks

below its on the oil pan

You need to remove the large metal cover plate.

See pdf for oil sensor replacement. Remember the 4Matic sump is a different shape to accommodate the drive shaft.

You know where to look if it is seals.

Good luck

gotcha!!
Thanks for all your help. So, I need to change/drain the oil prior to removing the sensor? I ask that only because I just changed the oil not too long ago... Don't want to waste fresh expensive mobile 1
I saw the pdf file, not sure what it all means... where can I get the sensor? Having a hard time finding it at autozone.... Thanks
Ant

I'm wondering if I should just change the o-ring....? That's probably what's leaking.... what do you think?

does this look like the correct sensor?
http://www.autopartswarehouse.com/sk...gs+Best+Seller

RMeuropean don't have, Parts.com don't have etc. You might get stuck with having to get it from a dealer. Make sure what is leaking & why - It might just need new O rings on the sensor.

Sorry - we posted over one another - eureka you found it!!.

Check what's wrong first.

I agree, if my assumption is correct, it looks like the dipstick tube is very close to where you remove the 3 bolts to take off the sensor, that doesn't match up to where the oil leak is, however.... oil travels, the o-ring could be leaking on the level sensor and the oil is traveling down the skid plate and drips onto the ground... possibly, I'm wondering if it's the drain plug gasket, thanks again!
Ant

The body of the sensor sometimes cracks from heat over time. As you say oil travels. Take the skid plate off & investigate properly.

Sounds good, problem is the link I sent you for the part shows a different looking sensor than the one in the pdf file you sent me..... not sure what the sensor really looks like...

You beat me to it. I wanted to expand. There have been a variety of oil level sensors fitted to M112 engines. There is the large two piece sensor in your diagram that gives the actual oil level in litres/quarts on the service screen. These cars had no dip stick fitted. My C240 had this. In some markets & in final production units a dipstick was fitted & a low oil only sensor. Then there was oil level, temperature & quality sensor. You will have establish which your car has. What I gave you in the pdf is the level, temp, quality sensor. I have limited 4Matic material. Please ask questions if not clear. I know the cars reasonably well.

Correction - sorry, I'm half asleep tonight - nearly 2am here. See additions above.

There is no dipstick, however there is a plastic plug that you can pull out and the dealer than can put in their expensive dipstick to check level. I have no way of checking my oil level, depend on the star trek dashboard

OK - well take off the metal skid plate & identify the location of the leak. We can take it from there. I will see if I can find the other sensor R&R pdf.

See my correction above. I'm half asleep tonight. There were 3 sensor types. Some EPC's don't show this.

ok, sounds great, thanks for all your help, I appreciate it!
Ant

One more thing. I thought pcy had this problem with his 320 4Matic. Found the thread. He had a hard time with it & maybe there are learnings here if it is your sensor leaking.

https://mbworld.org/forums/c-class-w...l+level+sensor

pcy is also very technically competent & if you find it is the sensor or sensor O ring maybe a PM to him would help you if he does not notice this thread. He has 4Matic experience.

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im going on assumption for now, will be getting under the car soon, if it was the transmission fluid wouldn't it be red? Im finding motor oil on the ground, why would you need to remove the pan? I though the sensor mounts to the pan? I'm confused....

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+1 must identify leak. The transmission electrohydraulic bush is a possibility but I've never seen it cause a "major leak". Make a slight mess yes. Anyway easy to identify.

i have, especially when it takes a crap.

also the oil level sender exit point of the block is above the oil level. so the only leaking or sweating would be caused when the oil sloshes around. as for the pilot bushing as soon as the car is on, trans fluid pumps throughout the trans. and it will leave a nice couple of drops almost immediately.

Depends which sensor his car has but you are likely correct on a 2005.

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