2009 C350 135K miles

Oil low indicator comes within 2 months of topping off oil and within 1K miles of driving. No obvious leaks on the floor. Is there any video that can point me step by step diagnosis for any leaks?

Thanks

 

have you gone under the car and removed the plastic undertrays to look? heres how if you dont already know:

https://www.pelicanparts.com/techart...body_Trays.htm

Im planning on servicing my trans so went under and removed that plastic panel just to check everything out ahead of time and noticed some fluid, I left the panel off and put a big piece of cardboard under overnight just to see if there were any active leaks and the cardboard was clean.

Im noticing a few oil stains on the engine, intake manifold, oil filter housing areas so just bought some UV dye to add to the oil. Just got it yesterday, going to put it in tomorrow before i go on a trip so it mixes really good with the oil. Then I got a UV flashlight to see where its coming out of. Im not dealing with low oil, more like oily gunk and seeing how active they are. I have no idea how long the stains have been there.

 

I took a picture near the PCV valve and see an obvious leak near it. So I will get that replaced. I don't remember replacing it in the past. So at 135K miles is probably a good time to do it. When I am getting this replaced is it a good time to replace other valves that may not be leaking now but it is a good time to replace it anyway? I was seeing this https://www.fcpeuro.com/products/mer...kit-oem-515810 and was wondering if it is a good idea to replace the whole breather kit. I am guessing it is a lot less in labor to replace multiple things at once and there will be lesser breakdowns.

Leak near PCV

 

I just replaced that cover MB Part# 2720100631 along with the oil drip pan behind it MB Part# 2730100162. That kit you posted is alot of money in my opinion, I went with the less expensive Febi brand breather cover, around $40 less. i got the Mercedes drip pan because that is the cheapest at FCP, where i happen to buy them. The breather hose shouldnt need replacing unless its brittle and somethings wrong with it, mine just had oil in it so i removed it when I removed the mass air flow sensor and elbow below it, dont even have to mess with removing the clamp that way. I just ordered the drivers side air oil seperator cover along with the oil filter housing gasket and oil cooler gasket which I need to replace. The hose on that side looks to be in good condition so i plan on cleaning, just unhook all the ends then run compressed air through it to push any oil out, carefully. The purge valve is connected to that hose and i dont seem to be having any issues with the valve so im assuming its not blocked or clogged with oil.


Heres the inside view of that cover and the drip pan behind it.

I have alot of photos of what ive done in this thread: Replacing the cover was actually easy with the right tools, i used an 8mm wrench for 3 of the bolts then I bought a 5/16 offset wrench for $5 specifically to reach the outer bottom bolt and it worked great. I didnt replace those round plastic covers just because mine arent showing any signs of leaking.

https://mbworld.org/forums/c-class-w...ks-yes-no.html

If youre having someone do the work then it makes sense to have them do it all at the same time. Have to remove the air box for all 3 jobs.

1- Passenger side breather cover and drip pan replacement. Also round plastic cover back of engine. That just pops right off and on.

2- Remove mass air flow sensor and elbow to clean breather hose, inside of elbow and clean throttle body.

3- Drivers side air oil seperator and clean/replace the hose. Also round plastic cover back on engine.

That should hopefully take care of any oil getting into the intake.