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My wife's 2012 C250 has started developing an annoying oil leak. In the morning after parking there is about 2 tbs worth of oil dripped onto the driveway. I've heard about the turbo line O-ring needing replacement which I'll probably do. But there doesn't appear to much oil leaking from that. I have replaced the camshaft plastic cover gaskets and oil plug gaskets about 2 years ago when I replaced the camshaft adjusters. But maybe next time I'll use a better quality gasket. I'm going to post a few pictures here in case someone notices something I may have missed. Personally I'm thinking cleanup the oil as best I can, start her up, let it warm up and see if I can figure out where it's coming from. Maybe use white baby powder to trace the path of the oil leak.
Passenger side heat shield Looking down passenger down Passenger side back of camshaft cover (oil pooling) Front passenger side (some oil residue but not much) Drivers side camshaft cover back of engine Drivers side under car looking up Drivers side under car looking up to transmission pan (weird rust spots on pan - some oil drips) Drivers side under car looking up Drivers side under car looking up Passenger side under car looking up (oil on exhaust) Passenger side camshaft cover back of engine again
My wife's 2012 C250 has started developing an annoying oil leak. In the morning after parking there is about 2 tbs worth of oil dripped onto the driveway. I've heard about the turbo line O-ring needing replacement which I'll probably do. But there doesn't appear to much oil leaking from that. I have replaced the camshaft plastic cover gaskets and oil plug gaskets about 2 years ago when I replaced the camshaft adjusters. But maybe next time I'll use a better quality gasket. I'm going to post a few pictures here in case someone notices something I may have missed. Personally I'm thinking cleanup the oil as best I can, start her up, let it warm up and see if I can figure out where it's coming from. Maybe use white baby powder to trace the path of the oil leak.
Passenger side heat shield Looking down passenger down Passenger side back of camshaft cover (oil pooling) Front passenger side (some oil residue but not much) Drivers side camshaft cover back of engine Drivers side under car looking up Drivers side under car looking up to transmission pan (weird rust spots on pan - some oil drips) Drivers side under car looking up Drivers side under car looking up Passenger side under car looking up (oil on exhaust) Passenger side camshaft cover back of engine again
Richard
@Richard Koop Well done with all the photos. What do you think is the cause, having completed the extensive inspection?
Where is the single point under the vehicle, where you find the oil drip from the first few sentences of your post? Start there and work upwards/higher until you find it.
Clean off all of the oil. Save the baby powder for babies.
So after cleaning up the oil and running the car for a while it was pretty obvious.... It's the valve cover gasket. I think mainly in the corners (see last picture). The gasket looks fine. Maybe a dab of gasket sealer in the corners to ensure a good seal? It's tough to find the gasket locally, it's only a few years old and not damaged at all. Also I'll ensure I don't overtighten it which apparently can cause leaks too.
Put the replacement gasket on but it was much skinnier than the original and I still have leaks... not in the same place but some leaks. So from the Mercedes Benz stealership I ordered a new gasket including the spark plug well gaskets..
So I'll make sure the surfaces are clean and I'll put a dab of RTV in places to hold the gasket in place when I set it on the engine. I find it tough to get the valve cover on the engine because I have to slide it under the harness. Is it worth trying to remove the front connectors on the harness (near the big plastic tube on the front) to move it out of the way? Also I figured if I get a new MB gasket set I shouldn't use RTV along the surface. Only enough RTV to hold the gaskets in place when I'm setting it on the engine. Make sense?
Put the replacement gasket on but it was much skinnier than the original and I still have leaks... not in the same place but some leaks. So from the Mercedes Benz stealership I ordered a new gasket including the spark plug well gaskets..
So I'll make sure the surfaces are clean and I'll put a dab of RTV in places to hold the gasket in place when I set it on the engine. I find it tough to get the valve cover on the engine because I have to slide it under the harness. Is it worth trying to remove the front connectors on the harness (near the big plastic tube on the front) to move it out of the way? Also I figured if I get a new MB gasket set I shouldn't use RTV along the surface. Only enough RTV to hold the gaskets in place when I'm setting it on the engine. Make sense?
Richard
@Richard Koop See below. Does the document address your vehicle? If not, please post your VIN. Note the low torque values, 8Nm and 9Nm. Overtightening will cause leaks. Buy a click-style torque wrench in the proper torque range, if you do not already have one.
So major leak solved by replacing the valve cover gasket and spark plug well gaskets. Still a very minor but annoying oil leak. Here's a video of the oil pan area where the drips are coming from.
The dried oil on the pan are probably from the major oil leak before from the valve cover gasket. So I think it's mostly the black plastic area on the bottom of the oil pan where the wires attach to (what is that exactly? Is that the oil pump?). Do you think it's worth maybe trying to re-torque the torx bolts in that black plastic area and maybe also the oil pan bolts for good measure?
Or do people think the gaskets have to be replaced? 120,000kms on the vehicle.
That engine is leaking like a sieve. What is the history of the vehicle? How long have you owned it, and how many miles have you put on it? I would clean all of the oil, so everything is perfectly clean. Then you can see where oil is coming from. The video is too shaky and moving around, and too many things are soaked with oil to guess what the problem is.
W204 C200, BMW E30 M3, 1980Gt Mini, Toyota Corona, KTM 200 EXC.
if you have oil leak around the oil drain plug and oil level sensor,,
Probably best have a look above the starter motor, see if oil is dripping from the oil cooler/oil filter housing if yes remove the starter and remove the oil filter housing replace the seal/gaskets for the housing and oil cooler gaskets.
Mine was slow leak in this area, use genuine ring gaskets.
So I definitely fixed a lot of the leaks by replacing the valve cover and spark well gaskets. But I still have one lower down. It's now at the point where I start the car and let it run for about 20 mins and I have a small pool of oil dripping from one area. Here's a few pictures.
And a video... not great but might show something...
It's definitely coming from behind/above the starter and not from the oil pan. It's really tough to see what's behind/above the starter. Any ideas?
I looked from the top and the valve cover gasket isn't leaking and I can feel all the way down the oil filter housing (at far as my arm will reach and it's dry too
Funny thing... I did find a torx bolt (about 1" long) in the splash shield when I removed it to check the leak. Hopefully it's one of the oil pan bolts.
Richard
Last edited by Richard Koop; 11-20-2021 at 04:07 PM.
what was the end result, what did you change out to fix the leak? My C250 same pics
Originally Posted by Richard Koop
My wife's 2012 C250 has started developing an annoying oil leak. In the morning after parking there is about 2 tbs worth of oil dripped onto the driveway. I've heard about the turbo line O-ring needing replacement which I'll probably do. But there doesn't appear to much oil leaking from that. I have replaced the camshaft plastic cover gaskets and oil plug gaskets about 2 years ago when I replaced the camshaft adjusters. But maybe next time I'll use a better quality gasket. I'm going to post a few pictures here in case someone notices something I may have missed. Personally I'm thinking cleanup the oil as best I can, start her up, let it warm up and see if I can figure out where it's coming from. Maybe use white baby powder to trace the path of the oil leak.
Passenger side heat shield Looking down passenger down Passenger side back of camshaft cover (oil pooling) Front passenger side (some oil residue but not much) Drivers side camshaft cover back of engine Drivers side under car looking up Drivers side under car looking up to transmission pan (weird rust spots on pan - some oil drips) Drivers side under car looking up Drivers side under car looking up Passenger side under car looking up (oil on exhaust) Passenger side camshaft cover back of engine again
Richard
What was the end result. What parts did you change out to fix the leak? My C250 Looks very similar to your pics. I'm thinking Oil filter housing and seals, oil line and oil pan gasket.
I think the bolt maybe from the oil sump on the top of the lip at the rear...I cant find any other place where this little bugger could be from..I'm guess that its fell out of the crappy plastic oil sump and that's caused the sump gasket to blow.ill get a better look once I get the car off the ground.
11-07-2020, 07:10 AM
