Does the oil get darker faster in a Bluetec?
Thread Starter
Member
Joined: Sep 2011
Posts: 119
Likes: 3
From: Indianapolis
car
Does the oil get darker faster in a Bluetec?
I've got a 2012 ML 350 Bluetec. Despite quite a few other issues, the diesel engine has been my favorite thing about the car, with no problems.
About a month ago I took it in for a Service A at 50K miles. Everything's been running fine, but a check engine light came on after a couple of weeks. I scheduled an appointment (tomorrow) to have it evaluated.
A couple of days ago, though, I noticed some oil drips underneath the engine. I've never had that before. I checked the oil level with the dipstick and it was fine, but noticed the oil seemed pretty black in color for having an oil change only a few weeks ago. From what I've read, it was normal for older diesel engine oil to turn black really fast. Is that also true with Bluetecs running low sulfur fuel? Or maybe whatever is causing the check engine light is contributing?
I am curious what they'll fine out about the oil leak. My understanding is that at least on their gas engines, most dealers use an oil extractor for oil changes. That makes it seem unlikely that the oil drain plug is leaking or loose. Maybe the tech who did the oil change was just sloppy and left oil in the underbody tray, which is now slowly dripping out?
Appreciate any thoughts!
Thanks
About a month ago I took it in for a Service A at 50K miles. Everything's been running fine, but a check engine light came on after a couple of weeks. I scheduled an appointment (tomorrow) to have it evaluated.
A couple of days ago, though, I noticed some oil drips underneath the engine. I've never had that before. I checked the oil level with the dipstick and it was fine, but noticed the oil seemed pretty black in color for having an oil change only a few weeks ago. From what I've read, it was normal for older diesel engine oil to turn black really fast. Is that also true with Bluetecs running low sulfur fuel? Or maybe whatever is causing the check engine light is contributing?
I am curious what they'll fine out about the oil leak. My understanding is that at least on their gas engines, most dealers use an oil extractor for oil changes. That makes it seem unlikely that the oil drain plug is leaking or loose. Maybe the tech who did the oil change was just sloppy and left oil in the underbody tray, which is now slowly dripping out?
Appreciate any thoughts!
Thanks
Senior Member
Joined: Jan 2011
Posts: 422
Likes: 52
From: McDade, Texas
W211 e320 CDI
Diesels in general turn oil darker, faster than a similarly well built gasoline or alcohol piston engine. I used to be bothered by this to the point I did far too many oil changes but even changing oil VERY frequently did little to reduce the coloration. I use the same oil in my Vespa 300 Super's modified motor as my 06' CDI, change both around 5k mile intervals, the oil that comes out of the Vespa looks almost like it did coming out of the bottle, not so much on my CDI.
I have both turbo and non turbo diesel MB motors and both show the same behavior, nothing to worry about really. I personally cannot bring myself to go much over 7k miles on an oil change with filter of course, but supposedly it's perfectly safe to go much longer than that, like MB suggests?
I have both turbo and non turbo diesel MB motors and both show the same behavior, nothing to worry about really. I personally cannot bring myself to go much over 7k miles on an oil change with filter of course, but supposedly it's perfectly safe to go much longer than that, like MB suggests?
Senior Member
Joined: Jan 2011
Posts: 422
Likes: 52
From: McDade, Texas
W211 e320 CDI
I own a car lift so I've never done the vacuum method of draining, just raise it up and drain it by gravity. I would guess that you might get a little more old oil out by gravity draining and taking your time, which would slightly reduce the speed at which it turned carbon black again?
MBWorld Fanatic!
Joined: Dec 2004
Posts: 4,268
Likes: 253
the oil on the cdi turns black almost instantly after a full drain oil change
and yes - never ever suck the oil through the dipstick tube. the way the oil pan is baffled you are guaranteed not to get all the oil
and yes - never ever suck the oil through the dipstick tube. the way the oil pan is baffled you are guaranteed not to get all the oil
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Joined: Apr 2014
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ML 320 CDI
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Super Member
Joined: Jan 2010
Posts: 563
Likes: 31
From: The Villages, Florida
2006 E320 CDI
I do not know what Alx is talking about in his post concerning the baffles in the oil pan. Regardless if you suck the oil out through the dipstick (from the bottom of the pan) or the drain plug, the oil will run off the baffles to the bottom of the pan. That is my story and I am sticking to it!
Mike T.
Mike T.
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