so ive been having an oil leakage problem with my 2012 c250 , it leaks oil from the bottom left side area , its not a very bad leak , its a slow leak and does not leak a crazy amount , execpt the other day it left a good amount of oil on the ground , i need help identifying the problem but mostly finding the parts i need to replace because i dont know what the parts are called. i will post a picture and it would be great if someone could identify the part and or problem.

i was also trying to change the spark plugs today , and what do you know there is oil on the coils and spark plugs .


please help will post pictures

 

Hey Man, looks like it could be the oil filter housing if you're saying its a driver side leak.

I just replaced mine as it was leaking pretty good. If you remove the belly pans, you should see the oil trace coming from above the starter.

Thats my first guess based off your pics and my own experience. I suggest you also do the oil fill cap test to see if your PCV system is working properly and not creating crankcase pressure blowing oil out of the seals.

check the threads from myself and others regarding "crankcase pressure from oil cap"
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Keep us updated, happy to help.


Ant

 

appreicate it i will look into that. i put the old spark plugs and coils back back in im going to test the pcv system.

as i was looking at it today i found a cracked clamp on one of the hoses but it is hard to identify what it is . i belive it is the crankcase breather hose check valve. here are some pics kind of hard to see due to i had to zoom in.
i belive these hoses or hose if there connected are the problem for the leak.

and also for the oil on my spark plugs that will be cause by the valve cover gasket?

 

Hard to tell but I think this is what you're looking at - https://www.autohausaz.com/pn/MB-2710180929 - this is the low pressure part of the PCV system. It connects to the vacuum lines that run across the valve cover and under the intake manifold. There is a check valve/drain that runs to the engine block. Near the driver side motor mount.

The high pressure PCV is built into the valve cover. If the high pressure PCV is not working properly at idle, it will create excessive crankcase pressure. That pressure forces oil out of the seals. Do the oil cap test with your car running at idle.

Also, if you have oil around your ignition coils, it could be coming from your oil cap (happened to me) or one of the ignition coils gaskets for the valve cover. Each ignition coil has its own gasket in the valve cover.

When my car had the excessive crankcase pressure, it blew oil out of the oil cap and oil filter housing. Swapped the valve cover and out and new oil filter housing and gasket on, car has been running mint since. And no more leaks.

Keep us updated.

Ant

 

Looks like theres some sealant smeared in one of the photos. Wonder if there was an oil leak before and someone used sealant to try and fix it? Im not sure if im seeing some sealant on that hose, or if its just dirty.

 

 

yeah man i did that , thinking it was the oil pan gasket whole time its else where lol

 

hey man i posted some pictures, thank you for your help so far

it looks like you were right as the lower pressure pcv was wet but not broken or cracked

if it is my high pressure pcv system thats bad what part would i need to replace?

if its not the high pressure pcv it must be the oil filter housing or the gasket for it.

 

Nice job man! I saw the pics you posted. that's the low pressure PCV. I bought the whole vaccum hose tree from Autohaus, the link I sent you.

Double check that your oil filter housing isn't leaking because you already have your intake manifold off. I also suggest you put new intake manifold gaskets on. (I did as a precaution)

We're you able to confirm it was the low pressure PCV that was leaking/broken ? Just want to make sure that I'm telling you the right things.

For the high pressure PCV, to fix that, you need a new valve cover. I went with an aluminum one off eBay. It came with the new valve cover and all the gaskets. ALSO, if you're planning to do that job, and you haven't ever changed your ignition coils and spark plugs, I suggest you do those too. Since you have to take the ignition coils off to remove the valve cover.

But back to your leak, double check it's not the oil filter housing. With everything you have out, you should be able to identify where it's coming from. Would hate for you to put it all back and it's still leaking. That centrifuge/check valve could be cracked OR if you have excessive crankcase pressure, it could be blowing the oil out of that where it goes into the block.

Keep us updated

Ant

Here's the link to my thread, check this out - https://mbworld.org/forums/c-class-w...e-oil-cap.html