Hi. I just got a '98 ML320 and I desperately need to know where to put the motor oil. As I look at the engine I see one big cap of some sort on the lower right-hand side and then just above it, a smaller cap ... which one's which. PLease help ASAP! Thanks so much.

An owners manual came with our vehicles, it is full of useful information. Do you have it?

If you have not gotton the answer yet. And assuming I understand your description.

AS you describe there are two "caps" right valve covers. There is one lower which is larger round and there is one upper that is smaller.

The one that is larger is the cap for the oil filter and cannot be revove by hand.

The owne above that is the cap for the oil. It has a "bar" that goes across the cap so that you can remove the cap by hand. Turn counter clock by hand.

good luck.

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Silver Honda Accord, 2006
Silver G500, 2003
Silver SLK-320, 2002
Black ML-320, 2000
Bule Porsche 993 Targa , 1997
Silver Merkur XR4Ti, 1987

When facing your engine, the oil filler cap is located right above the black oil filter (right side of engine), you can unscrew it counter-clockwise to remove it to add oil (make sure u get a funnel can get messy!) and the dip stick is red color located on the left side right behind the radiator..