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I have a 2012 Merc GL 500, Gasoline.
Last day during routine service, it was noticed that there are traces of oil leak under the transmission casing. Looks like it has just started.
I am attaching a picture of the same.
Can someone please throw some light on this, like what could be the possible reason and how serious it is
Most of what can be seen looks to be from a leak (spillage?) from somewhere else. Everything there looks as if it was blown there during driving. Take down all belly pans and clean ALL surfaces (including engine) REALLY well. During that process, you may be able to ascertain a possible start point for the leak by noting where the grime trail stops. Then monitor closely/often to see where it starts up again from. Could be engine oil, as well. Lot's of options as to where the leak could be originating (unless, again, it's from spillage). Oil dye is another route.
Side note... are those cracks on the housing normal? They are not the source of the leak, though.
Last edited by DennisG01; Oct 15, 2017 at 10:35 AM.
Looks like something soft but strong enough to damage the aluminum was impacted like a stump or piece of wood. I'd bet it is leaking from those cracks.
Thanks DennisG01..
Frankly I did not notice those cracks (if those are cracks) when I looked at the leak.
I am not sure if those are actually cracks. Looks like I have to once again have it checked
Or it could be the oil with dirt making those lines
I will post further update once I have it
I don't think the "cracks" are simply a dirt/oil/grime trail. It certainly appears to be physically cracks. Whether they are an issue or not, I do not know. They could be surface/minor cracks or they could be deeper. It does not appear that the leak (if there is one) is emanating from any of the "cracks", though - there would be a more obvious trail coming directly from the cracks. Especially since the dirt trail gets heavier as you look forward and up. The dirt/grime is coming from somewhere else and being blown down into that area.
There also looks like drip evidence from the bottom of the some of the bolts - but I can't say if it's actually leaking there, or if the oil has simply accumulated around the bolt head and wicked down. Either way, even if they were leaking, they are not causing the rest of what you see.
Clean it off real good - inspect further forward and up - clean that real well, too. It makes things much easier when you start with a clean slate.
Last edited by DennisG01; Oct 15, 2017 at 03:12 PM.
Hmm, as you said, I should wash it clean and take a closer look to see from where the oil is actually leaking and to make out how serious those cracks are.
Thanks a lot for your response..
Good luck - I hope it turns out to be something simple!
FYI, Brakleen makes simple work of cleaning things up. Start high, and work down. Grab a half dozen cans, just to be sure to have enough. The green cans are safer than the red - the red stuff has chlorine in it and can do seriously bad things to you if not used in a VERY well ventilated area.
True, it doesn't look like it is leaking from the cracks. Start at the front of the engine and work your way back. Looks like the fluid is Pentosin which could be coming from the power steering line, rack, or reservoir. They tend to leak at the reservoir so start there and work back.
First, figure out what it is - is it ATF? Then look for leaks in the AFT cooling loop, or from the transmission input shaft seal.
Is it engine oil? Start up top and look for leaky valve covers, sump seals, input/output shaft seals etc.
I've seen this one enough to seem to think that that's engine oil and the culprit is your rear main seal.
First, figure out what it is - is it ATF? Then look for leaks in the AFT cooling loop, or from the transmission input shaft seal.
Is it engine oil? Start up top and look for leaky valve covers, sump seals, input/output shaft seals etc.
I've seen this one enough to seem to think that that's engine oil and the culprit is your rear main seal.
Thanks for your response.
How serious is it if it is the rear main seal which is causing This?
From the looks of the pictures it does not look like Transmission Oil at all since it to dark and burnt.. It could be the rear main seal or valve cover gasket or flux capacitor (been doing 88 mph lately?). I would clean the area and use a leak detector. Mercedes has video if you have the Workshop Service Software on how do it.. Else you can use this video as a reference.
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Slideshow: A one-of-one U.S.-spec Mercedes-Benz SLR McLaren Roadster became even rarer after a factory-backed transformation at McLaren's headquarters.
