2013 S550 4matic.

Right at around 150,000 miles I started getting the "check oil at next refuel" warning light.

I just had the big water pump and front gasket and line job done, so the mechanic checked to make sure there were no leaks. clean as a whistle. he says burning oil for a car with that many miles is normal, due to the turbos.

I've serviced the car at the dealer from day one when the car told me it needed service.

Just isn't sitting right.

Could be the PCV system blowing oil back into the intake

cars are now designed to die - its been in development from most manufacturers since the early 2000s where they then knew how to basically makes them last for 55 years and the accountants extrapolated this to the end of the company...

as Germans (alongside the evil rich from Britain and a certain religion) are the main contributor to the worlds issues (using the USA and the positive attitude to deliver the plan). These criminals picked up on the dilemma many years back and Mercedes started on the make them die plan with their vehicles from 1990 and since spend most of their R&D budget on finessing the time to death

this sick designed in obsolescence currently allows for increased car sales - all the governments are in on the act - once they have stolen all your money you get the treat currently being tested out on Gazans

how is this diagnosed, and, how to repair, assuming this is the reason?

PCV is system that directs pressurized air from crank case to the engine air intake. Even new cars have exhaust gas blow by thru piston rings and these pressurized gases in the crank case need to be let out. Gases are directed with the pcv system to the air intake to burn the oil mist in the gases.

With high mileage engines the blow by gets bigger and it is normal for high mileage engines to burn more oil ant the only good fix is re-building the engine.

But 150000 miles should not mean engine burns lots if oil. I have a 2010 E550 with almist 190000 miles and it does not burn any oil between oil changes that I do every 5000 miles.

The cheap medicine for controlling oil usage is to use thicker oil. I use the recommended Mobil 0W-40 if available. Last time I bought 5W-40, which is also approved by MB.

I do not know MB pcv system but in my older cars it was just a rubber hose with a spring loaded valve that connected crank case to the engine air intake.

the early 221 had the 273 v8 engine, that sort of lasts well except for the coils and the cam chain chain issue on the early ones
latter 221 had the 278 v8, which apparently is an unreliable bag of rubbish

as I eluded too in earlier posts

the time to death is speeding up rapidly - its why the rich people lease it and fiddle the tax man, the super rich for 2 years, less well off, 3 years and the ones who think they are rich for 4 years (but those last ones end up paying a lot in servicing) - most of those will have few issues - then the junk is peddled on to the poor to get them further in debt...


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The warning light on the dashboard tells me to check oil at next fueling around every 900 miles. Oil changes have been done by the dealer and local foreign car specialist every 10,000 per the manual, and with Mobil 0w-40.

At 157,000 will going to a heavier oil like the 5w-40 help, or cause another problem?

I just had to have a spark plug and coil replaced and my mechanic said the plug was "pretty fouled."

drive too gently and piston rings forget how to work
high miles, cheap fuel, short trips, and too gentle on the throttle (once fully warmed up after a 10 mile drive) and plated bores stop working and they burn oil

This is exactly how my wife drives (96k miles, costco gas, 6 miles commute, never over a quarter throttle). I need to take the car out for longer trips more often as "preventative maintenance"

costco fuel in the UK is significantly cheaper - but the car seems slow and it drinks like a fish, so I stopped buying it

this criminal idea of ethanol infected fuel is horrible - a well renowned high performance bike shop near me was telling me they believe modern fuel is on a downward spiral after just 28 days sitting, and is usually delivered to the cheaper outlets around the three week mark from the refinery

all 5 vehicles I run have seen at least 20% increase in fuel consumption since ethanol infected filth became mandatory - if you do the maths it has to be at least 6% worse as ethanol's energy density is much lower - but to get at bad as the 20% I see, they must have created some other magic - of course for them less is more

Ain't nobody gonna accuse me of driving my car "gently." Almost all my mileage is highway speed.

but USA highway speed is tickover for a german car - if you think about typical german driving conditions they were designed to do 130 mph for 1/2 a mile, emergency stopping down to 60 mph, then stand on it again back to 140, on off every 20 seconds for 75 miles each time it was started....

its more the exercise they need not a steady 2.5k rpm - get them hot, rip the daylights out of it at least once a week

If it's the M278 then quite normal, according to Mercedes the engine can use, +0.8 or more liter oil pr 1000 km.

I'm the happy owner of a S500 with the M278 with 410.000 kilometres, all original - the engine uses between 0.6/0.8 liter oil pr 1500 kilometres.

​​​​​​So nothing to worry about.

You may want to look at these 2 threads. @S-PRIHADI started the technical deep drill and @calibenzdriver joined in to an improvement that is incredibly helpful and likely help you with your situatioon.

https://mbworld.org/forums/e-class-w...en-passed.html

Simultaneously a group on another forum start looking. Into a somewhat similar topic.

https://mbworld.org/forums/w212-amg/...solenoids.html

Once the 2 connected it has greatly expanded and the second link seems to have continued the trials and experience report backs.

Long reads but a lot of good information surrounding your topic and related issues.

While it starts talking about the M276 it is also applicable to the V8 engines such as the M278 and others.

Hope this helps.

oil pressure, as discussed in the first link in post #15 above, should be irrelevant to oil consumption - where the piston rings and bores are in a serviceable condition

oil pressure is helpful to get the oil round, keep it circulating quickly for cooling (which is why high performance car's squirt on the piston crown and it gets all over the bores - which is where the oil control rings gets rid back to the sump - ONLY WHERE THE OIL IS LIGHT ENOUGH GRADE FOR THEM TO COPE AT HIGH REVS - AKA the 5W30 the Manu says to use - not 40 grade treacle)... and of course, that pressure is to maintain the film on shell bearings, so under high load, high rev conditions the white metal isn't degrading

Maybe I missed it but how often do you change your oil?

A quart of oil every fill up is not horrible however people automatically assume it's got to be the piston rings although in most cases it is the valve guide seals. Big job but certainly not as big a job as rebuilding the complete motor. Years ago I had a 190E that was consuming massive amounts of oil and I did the valve guide seal job snd it instantly fixed the problem there was literally zero consumption afterwards the old valve guide seals were as hard as a rock. In fact some of them crumbled in my hand while removing the old ones! I'm not sure of the procedure on the S550 if it is a possible DIY? Maybe a mechanic can chime in

on these with plated bores its not going to be valve stem seals - but some hard exercise with your right foot when warmed up may help the rings remember who's the boss - free - and much easier/cheaper than buying decent oil at today's prices

So you're saying it needs an Italian tune-up! Take it out on the highway to about 120 MPH!

sort of, but 120 is just driving like a hair dresser

at least 10 miles to get it fully warned up - then around 20 minutes (with breaks in between to cool down) but some decent full chat blasts over 4 to 6k rpm for 15 seconds at a time - basally a 15 mile rally stage like you stole it - that's the Italian way, not a cruise at 120 with the roof down

Manufacturers use very different materials and design for stem seals and all other seals in the engine vs the bad old days of your 190E.

Stem seals just don’t happen to speak of.

As Botus accurately points out.... They need a proper Italian tune up more than weekly. The bent 12 in my first S-65 burned a fair amount of oil the first year I owned it. I figure an octogenarian owned it before me and never hammered on it. I hammered on it and changed oil regularly. Consumption dropped from a liter every 2-3 tanks of gas to a liter between oil changes. Ran great right up it spitting a main bearing shell into the chains.

Warmed up means thermostat open and oil temp to 80C.