Your problem is most likley valve guides that are worn and leaking oil. Correct replacement cost would be about $2600.00
That would get your cylander heads rebuilt and a new timing chain. However I have had valve guide seals replaced on a 420SEL with successful results before. Either way i would have a qualified MB technician look at your engine first.
01 ML55 AMG
92 500E (a few mods)
87 300E (lots of mods)
00 Chevy 3500HD Diesel Box Truck
68 18' Donzi Marine
06 GT i-Drive7 1.0 Mountain Bike (with GPS!
PREVIOUSLY OWNED:83 300SD, 87 420SEL, 88 420SEL, 90 420SEL, 86 560SEL, 86 190E 2.3-16V AMG, 94 E320