Service indicator gained 1500 miles?

[stevesey]

My service indicator had got down to 900 miles, checked it tonight - now showing 2400!!

I've only had the car one month, and was suprised the reading was so low when I first got it (2500). I should have checked and got the garage to do a service, pre-delivery. I'd only looked at the history which suggested it was half way between services, so I was planning an intermediate oil change (fan of 6K Oil changes) but didn't bother when I saw the indicator was so low.

In terms of recent history the car has spent 3-4 months on the forecourt and only did 1000 miles between April (MOT) and arriving on the forecourt, I've done about 1700 miles in the past month (lots of motorway). Wondering if the assyst system has taken a while to re-calibrate itself to the new driving profile?

So if it now says 2400 add the 1700 I've done it would have been worth doing the oil change when I first got the car!!

 

[jaymanek]

Yes you will find assyst changes to the type of driving you do...it works on both time and whether its motorway or city driving... its a clever little system and so dont be surprsied to see it go up and down...

 

[television]

These systems work on both time and mileage, if the car had been siting at a dealers for some time, the computer does do odd things sometimes, if you add some oil, this alone can increase the service interval

 

[stevesey]

These systems work on both time and mileage, if the car had been siting at a dealers for some time, the computer does do odd things sometimes, if you add some oil, this alone can increase the service interval

Guess what I did on Sunday

I guess that may have shocked the assyst into some kind of re-calculation based on the current driving profile. 2400miles will put the car at over 12000 miles - I'll see how quickly is starts going down (or up) - might be worth at least doing a filter change and associated top up (but that's not much) or just an early service.

 

[c240yaz]

An oil change would be more beneficial than a filter change. Ideally, best to do both.

 

[grober]

oil quality sensor

On the v6 engine there used to be a sensor which measures oil conductivity to monitor the state of the engine oil. Thats why if you add new oil or change it the service interval will be altered. I don't think it will reset completely from this alone though.

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.

 

[stevesey]

Interesting - although this didn't stop MB avoiding the problems they had int he US with people using mineral oil over the extended service intervals. One would hope the sensor would detect the shorter life of the oil and flag a service - perhaps the sensor isn't well calibrated for mineral oil.

 

[stevesey]

An oil change would be more beneficial than a filter change. Ideally, best to do both.

Once established I plan to change oil every 6-7K (half way between services) just don't want to an oil change for 2500 miles at present. Perhaps I will, but with one of the cheaper 229.3 brands as it won't be in there for that long.

Of course if an intermediate oil change will be picked up by the sensor and extend the service interval it might be easier just to stick to fixed intervals anyway.

 

[c240yaz]

I use the cheaper brand every 5k miles approx. Chevron Fully Syn. 5-40.

Just changed mine again after 4.5K miles. I never reset the service interval display at the time, and so far, no change in recommended service interval on the display. Still shows 6K miles to go until next service.

 

[stevesey]

I use the cheaper brand every 5k miles approx. Chevron Fully Syn. 5-40.

Just changed mine again after 4.5K miles. I never reset the service interval display at the time, and so far, no change in recommended service interval on the display. Still shows 6K miles to go until next service.

This is interesting reading - especially the very bottom bit where they deduce that the oil seems to take 3000miles to "run in". If you look at the earlier graph you can see the TBNs dive rapidly over the first 3000miles - it's almost like there are too many additives at the start.

That said, the test is interesting, but you can't really read anything into it because it's a sample of 1.

I'll still be changing every 6-7K.

 

[c240yaz]

Interesting reading, and some interesting results, but my perspective on this is, it is one group of "peoples" case study. I am sure if this same experiment was carried out here, by several groups, the results would vary significantly.

Would be interesting to put it side by side against what Mobil, or other oil manufacturer's Industrial Chemists woud say, to see what the disagreements would be. A bit too in depth for me though.

Some of the points mentioned are also contradictory to what is taught in this country, when one is serving their apprenticeship and attending college or uni, to gain their qualifications as a vehicle technician.

I will still be changing mine around every 5K miles, although not with Mobil due to the cost. When I smell the fuel content in the oil after this mileage, I know it is time to change. ( but not when there is snow on the ground, I am not that compulsive ! )

 

[ckember]

my service indicator was at 3300 left for an A service checked oil level needed a litre, added and assist said I had 5500 to next service. Have had this happen a few time now.

 

[c240yaz]

my service indicator was at 3300 left for an A service checked oil level needed a litre, added and assist said I had 5500 to next service. Have had this happen a few time now.

Mine must be faulty. I've done almost 1000 miles in the last week, no change.

 

[Benzowner]

Mine must be faulty. I've done almost 1000 miles in the last week, no change.

Not necessarily faulty, just no more contamination added to the oil. My assyst has been at 2000mile now for a week or so taking almost 2000 miles to drop from 2700 to the 2000 it now is.

 

[scgfull]

My Service counter extends itself after each service such that I can often get about 20K miles between services.

I have been assured repeatedly that Fully synthetic oil especially the better brands will last longer than this. I used to change the oil every 6 months/ 6000 miles when I used semi-synthetic and old mineral oil but not any more.

Steve

 

[Glenn Smith]

Personaly still a fan of regular oil changes, i change mine every six months (about 7500miles) i use a semi-synthetic of the correct spec. but not the expensive ones.