210san

I have a 2008 GL320CDI that is leaking oil and I can't figure it out. My engine oil needs to be changed and quite black in color. Yet my leak looks like new oil very light caramel tanish color. I have taken the skid plates off and still can't figure out where it is coming from. Anyone have ideas? Also my engine oil is full and not going down in level.

GLguy

Differential or transfer case perhaps. If it's in the front then check front differential for leaks. Could also be transmission oil, but I do not remember the color.

lkchris

You should be able to easily determine if it's differential oil by the sulphur smell. This artifically added odor and the artificial viscocity numbers are the mechanisms the oil industry uses to prevent your putting this oil in your engine. Differential fill and drain plugs use rubber O-rings rather than metal washers for sealing, and of course rubber doesn't last forever.

Your engine oil will smell like diesel fuel.

Your transmission fluid should be red.

You also have power steering fluid, which could be the color you see, but where you find the oil is always a clue.

I bought my 2007 GL320CDI new and the engine oil remained clear for a few hundred miles only. It's been black ever since--as with all diesels--even just after an oil change. In any event, color of motor oil is meaningless as regards any type engine.

DennisG01

You gotta get things nice and clean. Spotting leaks and following trails are much easier when things are clean. Look at where it drips on the driveway - gravity works so the spot it drips off of will be directly above. Start there and follow the trail.

Ditto the comment about engine oil color.

210san

Thank you all....it looks like my seal on the passenger side of the front diff

a2j

My engine oil is always black.....

smiledr996s

DennisG01

Are you running some type of bypass filtration system? Like an FS2500 or something?

smiledr996s

No have egr turned off with a tune. I just get excited not having it that black. I hated to see it look like that just after changing the oil. Not sure exactly how much if any ill effect the spot contamination causes

Fourdiesel

It isn't EGR that turns lube oil black in a diesel. It is unburned carbonized fuel in the exhaust gasses that blowby the piston rings. All diesels have it and it is NOT an issue.

smiledr996s

I am no expert but egr must have some effect. Unless it can be explained. Before my tune the oil was black as coal as everyone else’s. Since the tune the oil has become clearer and clearer with oil changes.