GL Class (X166) 2013-2015 after facelift became GLS (X166)

GL450 Oil in Coolant Reservoir

Old Apr 24, 2022 | 08:39 PM
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GL450 Oil in Coolant Reservoir

There is a little oil in my reservoir. When I look at old post they talk about the oil cooler gasket, but they are all about the X164. Is this also a likely suspect on the X166? Where is the oil cooler, it's not in the same place as the X164?
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Old Apr 24, 2022 | 10:28 PM
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Can you detect the type of oil - transmission or engine? Does the smell give any hint?

What is the year and VIN for the vehicle?

Last edited by chassis; Apr 24, 2022 at 10:40 PM.
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Old Apr 25, 2022 | 09:18 AM
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My first guess is engine oil. When I get some on a paper towel it looks black. Vehicle is a 2013 GL450.
4JGDF7CE1DA232554
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Old Apr 25, 2022 | 10:07 AM
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2014 GL450, 1992 W140 300SD, 1993 W140 300SE, 1987 E30 Convertible
Both oils look black. Oil cooler is on the front engine cover underneath all pooleys. Could be gasket, could be oil cooler itself. Transmission cooler is on the left side of radiator, just a pipe inside of it, small chance of leak.
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Old Apr 25, 2022 | 10:13 AM
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2014 GL450, 1992 W140 300SD, 1993 W140 300SE, 1987 E30 Convertible

On the right lower next to AC compressor
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Old Apr 25, 2022 | 04:15 PM
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So much stuff in there I can't tell what's going on. Can't find any past posts about it either. Does someone have the process needed to get the job done?
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Old Apr 25, 2022 | 07:54 PM
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Item 13, installed near the number 3 in the diagram. A gasket is also needed. Check your VIN at mbparts.mbusa.com

I don't have the WIS for this, but if it was my vehicle I would remove the front underbelly pan and spend time looking at it with a bright LED flashlight. From arsupisemnet's photo it looks like 4 screws to remove the cooler, and the coolant hoses which should be attached by squeeze spring clamps. Need the torque spec for the screws, don't want to strip the threads in the front cover.

I would drain the oil and coolant before removing the cooler. Coolant fill WIS is probably on this site somewhere for M278.





Last edited by chassis; Apr 25, 2022 at 07:58 PM.
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Old Apr 25, 2022 | 08:13 PM
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I actually saw it, it's really buried. I think I can work my way into it. Thanks
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