E220cdi - excessive oil consumption

[yellowbentines]

Hi all, first time poster but long time Merc owner.

I have an 08 E220cdi, when I bought it at 4,000 miles the oil level was checked and ok, at 6,000 miles the warning light came on (oil just below min on dipstick) and I topped it up with a full 1 litre bottle. another 2,000 miles later at 8,000 miles the warning has come on again. Is it acceptable for this enging to use 1 litre every 2k miles at this mileage/age, or should I be taking it to my dealer for an under-warranty check?

 

[Dieselman]

It should slow down on oil consumption after about 10k miles or so. Direct injection diesels often consume copious quantities of oil during the first 10k miles.

Find a long steep hill and cane it flat out up it, preferably with a heavy load on board. This will burn off any glaze that's forming so allow the piston rings to seat better.

 

[yellowbentines]

Cheers Dieselman, I'm not knowledgeable enough about diesel engines to know why I should need to do what you suggest, any further info would be welcome. I did try a few google searches, could I be consuming oil/glazing pistons because of frequent short journeys at low engine load (wet stacking?), this seems to tie in with your suggested remedy.

My local MB dealer has informed me today (over the phone, didnt take car in for inspection) that during the first 10k miles 1 Litre per 1k miles is perfectly acceptable.

 

[Dieselman]

I be consuming oil/glazing pistons because of frequent short journeys at low engine load (wet stacking?), this seems to tie in with your suggested remedy.

That's pretty accurate. The rings are forced out against the cylinder walls as a result of cylinder pressure.
Low load journeys don't provide enough pressure for the rings to seat properly when new so oil passes the oil ring and bakes onto the cylinder wall.
By loading the engine so the combustion pressures and temperatures rise it forces the rings out and they clean the cylinder walls.

If left too long the glazing can be irreversible other than an engine stripdown or using 'glaze busting oil'.

Diesel engines like to be fully loaded.

 

[yellowbentines]

Makes sense, my journeys are normally frequent but pretty short point-to-point or in traffic, all I need to do is find some clear, safe roads to cane it!

 

[Dieselman]

Steep hills are what you need, high load, not high revs.

 

[BlackC55]

MB say 1L per 1000KM is acceptable oil useage. You are well under that. As DM says load the engine with a steep hill and passengers.