Just picked up an 08 ML320 CDI with 109K miles and figure I should some preventative maintenance soon as the dealership sends over the maintenance history. What things should I consider replacing now?

Oil & filter Drain not suck
Fuel Filter

Clean sensors Air Flow?
Glow Plugs?
Clean EGR?
Clean Intake does it have the swirl valves?
Oil Additive (not sure if stiction is really a thing and if its a thing on this engine)
Injector cleaner

was also thinking about a tune to remove the DPF and EGR so I don't have any issues with them.

 

Just follow the car FSS.
I never used any additives on MB and had couple of them reaching 300k miles.

 

Change the oil and filter and live long and prosper. However watch out for the idiot that suggest taking fan blades off the fan to have the engine to run cooler!!


PS: Don't screw with the emissions system via a so called tune. If you are clever enough, you can eliminate the DPF via a software patch(google DPF removal)

 

What's wrong with a reflash to turn off EGR and DPF? Seen posts of UK and European areas doing this with good results. Would also be nice to have another 60ft lb for towing and better fuel economy.