Had my truck into the shop today for something and the guy who works the desk/counter came back to me and said the oil port seal needs to be replaced as it's leaking. He was not sure where it was located when I asked other than it was on the front part of the engine and the leak was leaking onto the serpentine belt...

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1999 ML 430

Its the square/rectuangular piece that is held in by two e-torx bolts (belive E10) right below/on the filter housing. In the middle of the square there is a plug with a Hex, that is where you would insert the pressure gauge for oil pressure diag. In order to replace, lossen and lift up (dont remove) the filter This lets the oil in the filter housing drain back down to the pan, otherwise all the oil in the housing will leak out when the plate is removed. After lifting the filter up, remove the two E-torx bolts and replace the seal....clean area.

Thanks. Sounds like a snap. Shop wanted to charge me $140 for this, lol.

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1999 ML 430