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Hi guys,
I have a slight oil leak forming around drivers side towards the back near the drain plug on the oil pan.
It is a 2004 C230 with 1.8L with 258,000km. It is a black coupe with no rust and I am willing to do whatever it takes to keep the car on the road. I am attached to it. Haha.
I am leaning there might be a leak coming from oil housing unit or oil cooler assuming it has got one?? If any
Can anyone confirm if I am required to remove the intake manifold to get to oil housing unit? Or if there might be another oil culprit in that area, don't hesitate to bring it up.
Any help would be appreciated.
Thanks!
You might want to put your location (at least the country) in your signature. At this point we have no idea if your car is LHD or RHD.
The engine (M271) is known for several leak points. However, we need to know where the leak is first. There are several threads about this stuff on the forum.
Profile updated. The car is LHD. Thanks Slammer111
I have actually had several oil leaks in last while and replaced valve cover gasket, plug gaskets, vacuum oil pump assembly, just finished replacing the timing chain and tensioner.
At the moment I have a minor oil leak just behind the alternator, I think it might be the plug on front of the block - need to remove the alternator and investigate.
This forum has been super helpful with all the repairs I've accomplished, can't say enough good things about it, but after all the research I haven't been able to find much in regards to oil filter housing removal specific to 1.8L M271.
The oil traces seem to be coming directly below the oil filter housing (not the oil filter cap) and is very minimal, but I would rather tackle it now before it gets worse or leaves me stranded.
At the moment I am trying to figure out if I can perform the task without removing the intake manifold?
The alternator is on the R side of the car. The oil filter housing is on the L (driver) side of the car. Other side of the engine. Are we talking about the same thing?
The only leak point I can think of behind the alternator is the vacuum pump. Personally I had quite the time with this thing in terms of intermittent random leaks. Eventually I determined that I probably had 2 leaks - 1 between the pump halves (failed o-ring - 100% failure rate for the older cars), and 1 at the gasket between the pump and motor. I ended up replacing the pump with a new unit to get the new updated o-ring, and also fixed the latter leak with a thin layer or RTV added to both sides of the thin metal gasket.
If you're talking about the wet spot in the intake past the MAF on the downward hose feeding into the supercharger, that is unfortunately normal. The intake gets a regular seep of oil from a hose connecting the valve cover.
Last edited by slammer111; Dec 30, 2023 at 01:54 AM.
FYI: I read in a German forum that the check valve inside the oil filter housing can go bad and drain all the oil inside of the filter over night (same on the M111) leading to a chain rattle 1-2 seconds after cold start.
It is replaceable if you remove the housing.
If you're talking about the wet spot in the intake past the MAF on the downward hose feeding into the supercharger, that is unfortunately normal. The intake gets a regular seep of oil from a hose connecting the valve cover.
I wonder if that's all it is then. Some of the oil working it's way down the hose and possibly making it's way towards the side of the block. I did not realize this was normal on these cars but did wonder about it. I will attempt to tear apart the air filter cover clean things up and keep a close eye on it. Thanks slammer111.
FYI: I read in a German forum that the check valve inside the oil filter housing can go bad and drain all the oil inside of the filter over night (same on the M111) leading to a chain rattle 1-2 seconds after cold start.
It is replaceable it you remove the housing.
Since I've replaced the timing chain and chain tensioner, the rattle has disappeared maybe 90-95%. I still catch a very slight maybe 1/2 second rattle on morning starts - not every time. I thought maybe it was normal.
If I get to the point of having to tear off the oil filter housing, I mind as well replace the check valve. Thanks for the link 112233. It's a BMW part you say - nice.
I removed the Air Filter Intake today and got under the car. I could not pin point where the oil is coming from. I run my fingers underneath and around the vacuum oil pump, valve cover, the head and got no traces of fresh oil.
From the top the oil filter housing looks dry, from the bottom my starter and the side of the oil pan is covered in oil - but it appears it's coming from above the oil pan gasket - I believe.
The air filter intake hose to which the MAF connects to is covered in oil.
Still investigating....... Air Filter Intake Hose Oil Filter Housing Drivers side shot of the engine block
I checked the PCV hose that is known to crack. The hose is in one piece and dry.
I am not sure if it's free flowing on each end, should I be taking it apart and performing any type of maint? Anyone know if any clogs appear on these?
There's an oil cooler right below the oil filter housing.
You need to remove the steering column and remove the starter to get access to it. If you're going to do so don't forget to disconnect the battery. Only other thing could be your rear main seal which mine is also leaking.
The oil cooler has a gasket that goes bad and needs to be replaced.
I lifted the car up again today and tried investigating oil leak around the area where the starter is located. I initially thought it could be the oil filter housing gasket or oil cooler gasket. Today I noticed there's a sensor next to the oil cooler just above the starter. The sensor is not super visible but looks similar shape to camshaft positioning sensor (I'm not saying that's what it is) with one hex screw holding it in place. I assume there's an o ring beneath the sensor, it is my suspect at the moment.
I have gone through the engine diagram online and haven't been able to pin point it.
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