Engine front oil leak
Thread Starter
MBWorld Fanatic!
Joined: Oct 2010
Posts: 5,142
Likes: 1,293
From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
Engine front oil leak
So, about five years ago my dealer told me my power steering pump on my 2010 E550 has gone bad as there is oil in front of the engine. I bought the pump but then started following the pump oil level and did not see it go down.
A couple weeks ago I get burnt oil smell and thought that ok, the time has come to replace the pump that I already had for some years ready to go in service. But that was not it.
I had oil leak from the oil filter housing, but I did not replace the gasket. I just re-torqued the bolts.
As the big m273 engine does not leave enough room to work in front of the engine I had to take the radiator fan out, which for my body was the worst part of the job as there is one screw and one wire tie to disconnect to get the fan out and for those I had to get under the car. Also had to disconnect upper radiator hose to be able to wiggle the fan out.
With fan out there is plenty room for the job and I believe with the small motors you have enough room without removing the fan.
As I was there I also replaced the two idler pulleys and the tensioner. Tensioner had to be out to get to all oil filler housing bolts anyway so it was logical to replace it.
No oil leak so far. Have not driven it much but not a drop tells me it could be a good fix.
I took this route as I don’t see any sign of oil in the cooling system or any coolant in oil. If I saw any of those I would have replaced the gasket.
This all is jut for info for members having “dirty engine front” problem as re-torquing the bolts is far easier that replacing the seal.
And boy, was my bolts loose. They had almost no tension at all.
A couple weeks ago I get burnt oil smell and thought that ok, the time has come to replace the pump that I already had for some years ready to go in service. But that was not it.
I had oil leak from the oil filter housing, but I did not replace the gasket. I just re-torqued the bolts.
As the big m273 engine does not leave enough room to work in front of the engine I had to take the radiator fan out, which for my body was the worst part of the job as there is one screw and one wire tie to disconnect to get the fan out and for those I had to get under the car. Also had to disconnect upper radiator hose to be able to wiggle the fan out.
With fan out there is plenty room for the job and I believe with the small motors you have enough room without removing the fan.
As I was there I also replaced the two idler pulleys and the tensioner. Tensioner had to be out to get to all oil filler housing bolts anyway so it was logical to replace it.
No oil leak so far. Have not driven it much but not a drop tells me it could be a good fix.
I took this route as I don’t see any sign of oil in the cooling system or any coolant in oil. If I saw any of those I would have replaced the gasket.
This all is jut for info for members having “dirty engine front” problem as re-torquing the bolts is far easier that replacing the seal.
And boy, was my bolts loose. They had almost no tension at all.
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Joined: Mar 2024
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From: Chicago
19 GLA45, 86 560SL, former: 14 E550 4Matic, 09 E350 4Matic, 83 240D manual, 78 450SLC, 81 500SLC
Nice work. It's good that you are consistently monitoring for oil-coolant mixing. It better be a frequent check though!
MBWorld God!
Joined: Dec 2019
Posts: 32,515
Likes: 6,350
Speaking of frequent checking, other than oil and fluids, recommend doing frequent checks of tire pressure as well, and note down the wear and brake pads/rotors. Reason why I mention tire, is because it is that one thing connects you and the car to the road after all, don't want to neglect that.
MBWorld God!
Joined: Dec 2019
Posts: 32,515
Likes: 6,350
So, about five years ago my dealer told me my power steering pump on my 2010 E550 has gone bad as there is oil in front of the engine. I bought the pump but then started following the pump oil level and did not see it go down.
A couple weeks ago I get burnt oil smell and thought that ok, the time has come to replace the pump that I already had for some years ready to go in service. But that was not it.
I had oil leak from the oil filter housing, but I did not replace the gasket. I just re-torqued the bolts.
As the big m273 engine does not leave enough room to work in front of the engine I had to take the radiator fan out, which for my body was the worst part of the job as there is one screw and one wire tie to disconnect to get the fan out and for those I had to get under the car. Also had to disconnect upper radiator hose to be able to wiggle the fan out.
With fan out there is plenty room for the job and I believe with the small motors you have enough room without removing the fan.
As I was there I also replaced the two idler pulleys and the tensioner. Tensioner had to be out to get to all oil filler housing bolts anyway so it was logical to replace it.
No oil leak so far. Have not driven it much but not a drop tells me it could be a good fix.
I took this route as I don’t see any sign of oil in the cooling system or any coolant in oil. If I saw any of those I would have replaced the gasket.
This all is jut for info for members having “dirty engine front” problem as re-torquing the bolts is far easier that replacing the seal.
And boy, was my bolts loose. They had almost no tension at all.
A couple weeks ago I get burnt oil smell and thought that ok, the time has come to replace the pump that I already had for some years ready to go in service. But that was not it.
I had oil leak from the oil filter housing, but I did not replace the gasket. I just re-torqued the bolts.
As the big m273 engine does not leave enough room to work in front of the engine I had to take the radiator fan out, which for my body was the worst part of the job as there is one screw and one wire tie to disconnect to get the fan out and for those I had to get under the car. Also had to disconnect upper radiator hose to be able to wiggle the fan out.
With fan out there is plenty room for the job and I believe with the small motors you have enough room without removing the fan.
As I was there I also replaced the two idler pulleys and the tensioner. Tensioner had to be out to get to all oil filler housing bolts anyway so it was logical to replace it.
No oil leak so far. Have not driven it much but not a drop tells me it could be a good fix.
I took this route as I don’t see any sign of oil in the cooling system or any coolant in oil. If I saw any of those I would have replaced the gasket.
This all is jut for info for members having “dirty engine front” problem as re-torquing the bolts is far easier that replacing the seal.
And boy, was my bolts loose. They had almost no tension at all.
Well done! Glad to hear it and thanks for sharing.
Thread Starter
MBWorld Fanatic!
Joined: Oct 2010
Posts: 5,142
Likes: 1,293
From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
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MBWorld God!
Joined: Dec 2019
Posts: 32,515
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Hence why I was glad to hear you got it done and fixed : ) also thank you for sharing so forum members that come across the thread can benefit from your information.
Thread Starter
MBWorld Fanatic!
Joined: Oct 2010
Posts: 5,142
Likes: 1,293
From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
And this job I think is easier for not needing to remove the fan, I hope.
MBWorld God!
Joined: Dec 2019
Posts: 32,515
Likes: 6,350
I have a 2012 S550 and I bought new idler pulleys and tensioner for that too. I do not know if these have already been replaced as they look very good but as I found the loose bolts on the E I will check the S and as I probably need to remove the tensioner for access to bolts like with the E I will just replace it with a new one.
And this job I think is easier for not needing to remove the fan, I hope.
And this job I think is easier for not needing to remove the fan, I hope.
Thread Starter
MBWorld Fanatic!
Joined: Oct 2010
Posts: 5,142
Likes: 1,293
From: Southern US
2010 E550, 273 Engine: 2012 S550, 278 Engine
I have a 2012 S550 and I bought new idler pulleys and tensioner for that too. I do not know if these have already been replaced as they look very good but as I found the loose bolts on the E I will check the S and as I probably need to remove the tensioner for access to bolts like with the E I will just replace it with a new one.
And this job I think is easier for not needing to remove the fan, I hope.
And this job I think is easier for not needing to remove the fan, I hope.
With the m278 engine there is no access to the oil filter housing bolts like on the m273 engine. I ended up just changing the two pulleys and the tensioner and the belt. Still need to get one more pulley as this one has 3 of them...
