Servicing - oil type & computer settings

[stivesvelo]

Re:2002 W210 320 cdi -

After a service I notice that the mileage till the next service starts counting down from 13k miles & eventually asks for a service after something like 19k miles.

I was told that the system is able to monitor the oil condition to determine when the service is due.

Does anybody know how it does this as there are so many different types of oil, synthetic, semi-synthetic etc. Does the computer need to be set for different types of oil & is it possible to do this without the special Mercedes software?

I have sneaking suspicion it works it out by measuring the amount of fuel passed through the system, ie. if you drive gently it uses less fuel & extends servicing, if you drive hard you usse more fuel & need more frequent servicing, if you put semi synthetic it shortens the period & if you put fully synthetic whiz bang oil in it gives a longer period, all based on a model stored in the computer. Just my theory though!

Curious to know if the 'monitoring oil condition' is a bit of flannell to impres us?

Rob

 

[Miffy]

Not sure how it calculates it all, but on Star is shows not just the quantity, but the quality of the oil. It also seems to be able to keep tabs of the amount of oil that is refilled. Its all clever stuff

 

[Nuclear Bob]

I don't think its that clever. It measures the level and also long or short drives and time, but not much else. Over 120,000 miles I have kept a check on mine, and it doesn't recognise oil quality (no difference between synthetic and ordinary). I average about 140 miles between every 100 mile drop in service indication.

 

[Miffy]

If you look at the Oil on Star, it grades the oil quality, not saying it knows what type of oil, just it says Oil Quality 3 (range 1 to 4) Tells you how much oil was filled on the last change

 

[stivesvelo]

Bob,

I'm sure someone mentioned an oil choice when entering the service into the computer some time ago. Would it take this into account when giving service indication or do you think it makes no difference, also is this setting only available if you use the Star software?
I'm wondering if it was serviced by a dealer without the Star would they have access to this function on their computer system & would it not differentiate between synthetic & ordinary.

I'm only speculating as I don't have any knowlege of this & would like to ask the right questions when an independant offers to service the car.

Rob

 

[jberks]

Certainly 211s have to be preset on fully or semi synthetic.

The engine does have an oil quality sensor. Can't remember exactly how it works, something like either it shines a light through and measures clarity or else its electrical conductivity, but either way, yes it is that clever.
If you're down to 1k to the next service and you are able to pop in 1l of new stuff, it will often give you another 1500 miles in return. It takes 100 miles but clearly the new stuff raises the clenliness of the old stuff and assyst responds accordingly. Sadly, it worked on my 210 but not my 211.

 

[stivesvelo]

Here, try this.......... http://www.oilanalysis.com/article_detail.asp?articleid=562

DaimlerChrysler Corporation Flexible Service System

DaimlerChrysler’s version of the oil monitor is called ASSYST in Europe and the Flexible Service System (FSS) in the United States. Like GM’s sensor, the FFS uses a computerized system to track multiple engine operating conditions. From research on oil quality through the span of an engine’s life, Daimler discovered that the breakdown in oil is determined by such factors as driving habits (frequent short trips vs. long trips), driving speed and failure to replenish low oil levels. Therefore, the FSS monitors time between oil changes, vehicle speed, coolant temperature, load signal, engine rpm, engine oil temperature and engine oil level. It uses this information to determine the remaining time and mileage before the next oil change and it displays the information in the vehicle’s instrument cluster.

In addition, Daimler discovered that oil degradation is correlated directly with its ability to conduct electric current. Therefore, Daimler has fitted V-6 and V-8 engines with a digital oil quality dielectric sensor, that is mounted above the oil pan along with an analog oil level sensor. This sensor measures changes in capacitance, which effectively is a proxy for the amount and type of contaminants and oil degradation products present in the oil. An increase in dielectric constant (less resistance to electrical flow) indicates oil contamination and degradation.

Daimler-Benz (Mercedes-Benz) has been incorporating the sensor into its vehicles since 1998.