after many parts replacements hoping to cure problems on my ML320. , I can say this, there are many answers for a simple question...like why do i use oil.
In a perfect world no, you shouldnt burn even a quart between oil changes.
it can be a stick ring, too low octane gas, worn rings, contaminated oil, your computer out of sinc, some silly emission control thing , vacuum leak , etc.
maybe when we all switch to hydrogen engines we can eliminate all the emmission contral stuff and have simple engines like pre-1970's.

steve

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Steve Danville
what i did myself.
CPS
rear shocks
MAS x 3.
SparkPlugs (twice)
Fuel pump & Filter
Window switch
replaced both failed horns with Honda horns.
Cleaned ERG Tube
Oil changes
Oil consumption Fix
Brake Pads
A/C Recharge
Anti-Freeze change X 2.
Front Shocks. Monroe. $90
Mercedes Warrenty Work:
Harmonic balancer,power steering clamp. Cat converters.Drive Shaft Bearing.s
Replaced Outer Lower Tie Rods and front lower ball joints at 156,000 miles