Oil Service Required

[Clan]

Originally Posted by Tatsfield

So are we saying that they actually haven't stopped the regen dumping fuel into the sump but have doctored the electronic fill levels and warnings to reclassify 75% as 100% and by so doing allow 25% of the sump to contain dumped fuel before the warning occurs? If so, how healthy is it for an engine running with its lubricating oil diluted by up to 33% diesel fuel? This situation would occur before any warnings were displayed!

Fuel doesn't get dumped into the sump , it hasn't been a problem for many years since they did the lower oil level modification and new software ... Hopefully you get your software updated regularly ... diesel is far less damaging than petrol due to it's oily nature ..

[Tatsfield]

Sorry my writing style! Dumped or not, it does end up in the sump. So the two things I take from your post are that the diesel dilution is less harmful than petrol and that they haven't stopped it from happening but have reclassified the 100% oil fill level and the overfill warning level. I can live with that if I can be assured that even the less damaging diesel fuel contamination will not reduce the operating parameters of the oil. My software is routinely updated and is fully up to date.

What worried me was that the oil manufacturers hardly designed the oil to have to carry an addition of 33% of the original oil volume of diesel fuel and that the spec of the oil must reduce because of this. If I can be assured that the oil can handle this abuse then I can stop worrying about it. Of course I assume that the amount of petrol finding its way in the lubricating oil in a petrol engine is far less than the amount of diesel from failed regeneration cycles but maybe the oil can deal with lesser amounts of petrol in the same way that it may be able to deal with larger amounts of diesel. Neither Volvo or the oil manufacturers would seem likely to want to publicly pronounce on this aspect of engine lubrication.

[RS3100]

Assuming the sump capacity is around 5.7 litres and the difference between the max and min marks on the dipstick is in the normal region of about 1 litre, reducing the maximum oil fill level by a quarter of the dipstick scale allows for a maximum dilution level of a tad over 4 per cent of oil volume by diesel and other by products of non-spontaneous regenerations. I can't see where you are getting a sump 33 per cent full of diesel from? To get to that level you would have to somehow lose over 2 litres of oil and replace it with fuel!

[green van man]

I don't worry about it, the oil is designed for 18,000 mile changes and my car does 6000 a year, so my oil is only a third used when changed.
If oil contamination is a worry I would just do an interim oil change at 9000 miles on a big miles a year car.

I change the landrovers oil twice a year and that does prehaps 8000 a year, it does however get driven through ford's and water troughs where water contamination is a possibility. Hot engine, cold water and it's possible for water to be sucked in past the oil seals which are designed to keep oil in not water out.

Paul.

[RS3100]

Dilution of the engine oil by small quantities of fuel is a feature of most if not all diesel engines with DPF technology. Modern emission control technology compatible oil is designed to cope with a certain amount of fuel contamination. Many vehicles have software algorithms in their ECUs that calculate the likely condition of the oil based on the number and type of regenerations occurring, and notify the driver if an earlier than scheduled oil change is required. If the oil change schedule is 12 monthly I personally wouldn't be worrying about it. Most software interventions seem to occur on vehicles with 24 month or longer scheduled oil changes.

[Clan]

Originally Posted by Tatsfield

Sorry my writing style! Dumped or not, it does end up in the sump. So the two things I take from your post are that the diesel dilution is less harmful than petrol and that they haven't stopped it from happening but have reclassified the 100% oil fill level and the overfill warning level. I can live with that if I can be assured that even the less damaging diesel fuel contamination will not reduce the operating parameters of the oil. My software is routinely updated and is fully up to date.

What worried me was that the oil manufacturers hardly designed the oil to have to carry an addition of 33% of the original oil volume of diesel fuel and that the spec of the oil must reduce because of this. If I can be assured that the oil can handle this abuse then I can stop worrying about it. Of course I assume that the amount of petrol finding its way in the lubricating oil in a petrol engine is far less than the amount of diesel from failed regeneration cycles but maybe the oil can deal with lesser amounts of petrol in the same way that it may be able to deal with larger amounts of diesel. Neither Volvo or the oil manufacturers would seem likely to want to publicly pronounce on this aspect of engine lubrication.

your writing style is fine .. Have you actually got a rising oil level problem yourself or not? It is very rare now on the older models and even more rare on the current ones ..

[Tatsfield]

No oil rising as far as I know. My interest is that even if the oil level remains constant, if there is fuel dumping in the sump balanced by oil usage, the quality of the oil will not be as originally specified and that might increase engine wear. So my question was whether the software modifications put in by Volvo in response to the oil dilution problem eliminated the dumping of fuel during abortive regeneration or whether they merely made room for oil level rises by reconfiguring the oil level limits. My 2012 XC70 is a keeper and probably the last car I'll own, so I just am interested in whether there is any problem below the radar which could shorten the engine life. Also understanding my car better helps with peace of mind.

My reference to 33% dilution was based upon the oil fill being reduced to 75% allowing 25% room for fuel dumping. 25% is a third of 75%. I'm not saying that my car actually has that degree of oil contamination, merely asking whether Volvo have actually allowed this large margin of contamination before the oil level sensor issues any warning. If the software upgrades have reduced the degree of contamination, why leave such a large margin to cope with it? This is just me being curious about the way Volvo design and develop engine modifications as I found it hard to believe that they could have put an engine out with that degree of tolerance on what is an unwanted side effect of DPF regeneration. Discussion rather than complaint.

[RS3100]

Originally Posted by Tatsfield

My reference to 33% dilution was based upon the oil fill being reduced to 75% allowing 25% room for fuel dumping. 25% is a third of 75%. I'm not saying that my car actually has that degree of oil contamination, merely asking whether Volvo have actually allowed this large margin of contamination before the oil level sensor issues any warning. If the software upgrades have reduced the degree of contamination, why leave such a large margin to cope with it? This is just me being curious about the way Volvo design and develop engine modifications as I found it hard to believe that they could have put an engine out with that degree of tolerance on what is an unwanted side effect of DPF regeneration. Discussion rather than complaint.

The range between the maximum and minimum marks on the dipstick doesn't represent the entire contents of your sump, just a relatively small range in which the level of oil in the engine is within the ideal operating tolerances. That upper 25% of the scale on your dipstick represents somewhat less than 5% of the total quantity of oil in the engine, so whilst any dilution with fuel is undesirable, it is nowhere near the level you are assuming.

I can't comment on whether or at what point Volvo consider the level of contamination to be excessive, but small quantities of fuel entering the sump during certain types of regeneration cycles is a feature of almost all modern diesel engines with emission control technology.

I also have a Ducato van. Dealers normally refill the oil to 0.4 litres below maximum to allow for a margin of dilution in use. On that vehicle, there is a software algorithm in the ECU which assumes a certain amount of contamination according to driving conditions, type of usage and the number and type of DPF regenerations. The counter alerts the driver if it considers that the oil needs to be changed prior to a scheduled service. Scheduled oil changes are at 24 months intervals on that vehicle. I change mine annually, but that's another story.

[RS3100]

Just a quick follow-up. 5 minutes on google and I found that up to 5% oil contamination with fuel seems to be the accepted norm across the motor industry in general, and that laboratory tests on modern diesel oils in Germany found that those oils remain within specification up to around 13.5% dilution.

[Clan]

Originally Posted by RS3100

Just a quick follow-up. 5 minutes on google and I found that up to 5% oil contamination with fuel seems to be the accepted norm across the motor industry in general, and that laboratory tests on modern diesel oils in Germany found that those oils remain within specification up to around 13.5% dilution.

Those figures are about what volvo mentioned in the service bulletin about 10 years ago .