Oil Cooler and Oil Filter Housing
Thread Starter
Member
Joined: Dec 2009
Posts: 115
Likes: 13
From: Maryland
S550 4-matic
Oil Cooler and Oil Filter Housing
Hello all, my 14 S550 with M278 engine is leaking oil at the oil cooler and oil filter housing. More at the cooler than the housing, took covers off and all oil is on the driver's side on bottom of engine and can see it leaking from the cooler. Question I had seen a lot of videos and suggestions on how to replace everything. With the turbo coolant lines, I was going to replace both sides, but I see some videos say just cut and splice the plastic hose with new rubber hose and clamps and new fittings to the engine block/distribution valve but leave the aluminum lines alone with the difficulty of getting them on an off. Anyone try that method is it worth it or since I'm going that far in getting to the oil cooler and housing just fight with the lines on the turbos. I appreciate any help and suggestions.
Member
Joined: Mar 2020
Posts: 91
Likes: 43
2013 W221 S550 2016 C217 S550
If you like working on cars, you will love this job. LoI. I am right in the middle of changing the oil filter housing and oil cooler gasket on my c217 m278. I previously resealed the timing chain covers, but still had some oil sweating around the air conditioning pump. Not a big leak, but whatever. Didn't want it to get worst. I would remove the radiator fan for more access. You will have to drain the coolant. It will all come out when you take out the fitting on the radiator. Drivers side when you remove the fan. Taking out the fan isn't fun. The turbo cooling lines are obstructing the lowest bolts on the oil filter housing. You need to move them out of the way. If you loosen and remove the one on the water pump you probably break the fitting and some of it will stay inside the water pump....I will get a new cooling line and spice a new rubber line in using the new fitting and on to the aluminum part of the turbo cooling line after I cut out the plastic line. I am worried about the bolt holding the cooling lines at the turbo. Not sure how easily it can come out. I don't wanna risk any damage to the bolt holding them on. If I strip it or break it, there isn't any room to fix that with a new thread. Might have to raise or remove the engine to fix that as far as I can tell. That would be a total nightmare.
Last edited by red996; Jan 2, 2026 at 05:10 AM.
Super Member
Joined: Jun 2025
Posts: 784
Likes: 248
From: USA
Hello all, my 14 S550 with M278 engine is leaking oil at the oil cooler and oil filter housing. More at the cooler than the housing, took covers off and all oil is on the driver's side on bottom of engine and can see it leaking from the cooler. Question I had seen a lot of videos and suggestions on how to replace everything. With the turbo coolant lines, I was going to replace both sides, but I see some videos say just cut and splice the plastic hose with new rubber hose and clamps and new fittings to the engine block/distribution valve but leave the aluminum lines alone with the difficulty of getting them on an off. Anyone try that method is it worth it or since I'm going that far in getting to the oil cooler and housing just fight with the lines on the turbos. I appreciate any help and suggestions.
Newbie
Joined: Nov 2024
Posts: 5
Likes: 2
2010 Mercedes S550
Hello you S550 W222 enthusiasts!
Just completed this job:
R/R Oil cooler & gasket. Torqued to specs.
R/R Water Thermostat Housing & gasket. Torqued to specs.
R/R Upper Cam Covers resealed & new bolts
R/R New Actuators & Seals
R/R New Cam Sensors
R/R New Serpentine Belt
Installed Pigtails to Sensors & Actuators
R/R New Turbo Cooling Lines (driver side). Purchased 2 aftermarket Lines, cut away the plastic connector ends, used new rubber tubing to rebuild.
What a job!! Not for the faint of heart. Every bolt put back & tightened to specs.
Turned the key - Waalaa.
Thanks to all the Posts givning me insight & tips on getting the job done!
.
Just completed this job:
R/R Oil cooler & gasket. Torqued to specs.
R/R Water Thermostat Housing & gasket. Torqued to specs.
R/R Upper Cam Covers resealed & new bolts
R/R New Actuators & Seals
R/R New Cam Sensors
R/R New Serpentine Belt
Installed Pigtails to Sensors & Actuators
R/R New Turbo Cooling Lines (driver side). Purchased 2 aftermarket Lines, cut away the plastic connector ends, used new rubber tubing to rebuild.
What a job!! Not for the faint of heart. Every bolt put back & tightened to specs.
Turned the key - Waalaa.
Thanks to all the Posts givning me insight & tips on getting the job done!
.
MBWorld Fanatic!
Joined: Jun 2021
Posts: 3,110
Likes: 1,346
From: Fleriduh
W212 E63S Wagon - GSL580 - E63 - E350 - C300
Cut and splice the plastic lines. It's the realistic way to go unless you're pulling the turbos. Fighting those corroded aluminum lines is a nightmare in the car. Just use good quality fuel line and constant-tension clamps. Replace the seals on both the cooler and housing while you're in there.
Many of us have replaced with silicone and had great luck.
