Is it ok to run a 25% diesel 75% oil mix in a 2.0D?

[chrisdc]

Is it ok to run a 25% diesel 75% oil mix in a 2.0D engine?

I'm going to have to make a decision this week on the fate of my car. As documented elsewhere, my car has done under 4000km since it's last Volvo dealer service. At present, according to an independent analysis of my oil (sample taken by another Volvo dealer and outsourced to specialist analyst), there is a 10% presence of diesel in my oil. All things being equal, by the time I get to 8000km this figure will have reached 20% and by 10,000km (next scheduled oil change) I’ll be running a 25% diesel 75% oil mix in my sump. Will this mix be good for my engine, turbo etc.?

I am under the impression oil plays an absolutely critical role in an engine. Any old oil simply won't do. Some oils are even “co-engineered” by both the engine manufacturer and the oil manufacturer. The dealer approach to dilution of engine oil with diesel seems to be limited to draining off the excess. I'm no expert but simple common sense tell me this is a bad idea. What do you guys think?

[SonyVaio]

I think it is preposterous!

That level of oil dilution will certainly do no good what so ever to the engine/turbo. I would highly recommend a complete oil change.

A slight dilution would be okay but 1/4 of your oil level being diesel can't be good. They need to tackle the cause of the dilution (change the DPF and stop the constant regens).

[chrisdc]

Originally Posted by SonyVaio

I think it is preposterous!

That level of oil dilution will certainly do no good what so ever to the engine/turbo. I would highly recommend a complete oil change.

A slight dilution would be okay but 1/4 of your oil level being diesel can't be good. They need to tackle the cause of the dilution (change the DPF and stop the constant regens).

Thanks SonyVaio,

As long as it's only me who seems to be concerned, i'm worried dealer is not going to take this seriously. That's why i'm trying to drum up some forum support. Now if Clan were to chip in At least i'd have some ammo from a respected official Volvo tech.

I appreciate your reply (on my other thread) about all V50's being recalled, by the way. This is just the sort of response that will add credibility to my case. Thanks given.

[Dieselfan]

Originally Posted by chrisdc

Is it ok to run a 25% diesel 75% oil mix in a 2.0D engine?

I'm going to have to make a decision this week on the fate of my car. As documented elsewhere, my car has done under 4000km since it's last Volvo dealer service. At present, according to an independent analysis of my oil (sample taken by another Volvo dealer and outsourced to specialist analyst), there is a 10% presence of diesel in my oil. All things being equal, by the time I get to 8000km this figure will have reached 20% and by 10,000km (next scheduled oil change) I’ll be running a 25% diesel 75% oil mix in my sump. Will this mix be good for my engine, turbo etc.?

I am under the impression oil plays an absolutely critical role in an engine. Any old oil simply won't do. Some oils are even “co-engineered” by both the engine manufacturer and the oil manufacturer. The dealer approach to dilution of engine oil with diesel seems to be limited to draining off the excess. I'm no expert but simple common sense tell me this is a bad idea. What do you guys think?

Wow! That's a lot of diesel fuel contamination. The recommended limit for diesel fuel in oil is 2% before most oil labs flag it as out of limits. If you are using an X/40 weight oil, no real harm is going to be done until is reaches about 5% and some diesel does burn off if you do a longer motorway trip.

Obviously something is probably wrong with the injection system (Is this engine smoking at hot idle?), the ECU map (Has it been fiddled with?) or something more serious like bad valve guide oil seals or even the rings.

The main effect of fuel contamination is that it thins the oil to a lower viscosity, so if you can't fix the problem, just keep changing the oil (There is no need to change the oil filter every oil change, every 10K miles is fine).
If you think the oil has 20% fuel in it (Is it rattling?) by 10K km, then I would dump the oil every 2500 km to stay within reasonable limits until you figure out what to do about the problem. Some engines with a DPF can also suffer fuel contamination if the recycle burn off system is defective and keeps functioning too often.

If the engine is not smoking at hot idle when you walk round the back, I would suspect an ECU map fault. If it's burning oil then the valve guide oil seals or rings are bad. If you don't want to fix them as that's going to be expensive, just move up to a 10/60 high mileage oil (Eg Mobil EP 10/60) that has some seal conditioners and is thick enough to tolerate more fuel contamination. That might allow you to change the oil every 5K km. If that's a bit expensive then just use a cheap 10/40 and keep dumping it, otherwise something is going to fail (Turbocharger bearings first probably).

Have you had a check engine light warning? also if you visit a Volvo dealer, it would help to get the codes read (There might be some kind person with a reader that will work on a 2.0D around). That might identify an ECU fault, that is either causing a rich mixture, warm up cycle failure or stuck in DPF burn off mode.
One final question, does the thermostat function correctly, because if it's stuck open that can stop the engine going into lean burn mode and keep the mixture too rich, although I don't think it would cause such severe fuel contamination as you have, my best guess is the DPF is blocked or the ECU is defective (Or a sensor). If the regen cycle (I tend to call it burn off mode) keeps operating, that will contaminate the oil. A new DPF is not cheap, so if you are out of warranty, try the scrap yards.
There are some companies making a DPF cleaner that you spray into the unit, but I have no idea if they work or not. DPF's are one silly idea that was forced upon the car industry by green party fanatics in the EU.

[chrisdc]

Hi Dieselfan,

Thanks for that very detailed reply. To answer your observations and questions, the oil is whatever grade Volvo dealerships use here in SA. I’m not sure but I suspect it's 5w30. The car has been dealer serviced since new. I never see smoke coming from the exhaust, I'm not even sure which side of the car it's on, that's how unobtrusive the emissions are.

The car is stock standard. As far as I know, the ECU has never been touched. I've only owned the car since December last year but here in SA these cars are sold with a 5 year 100,000km maintenance plan. Any tampering with the car would invalidate the plan and the warranty so people generally don't mod their cars until the plan expires.

Since the analysis confirming the 10% diesel content, the dealer has opted to change both the oil and the filter. The figures of 20 and 25% were my projections based on current rate of contamination if the oil were not changed and left in for the full 10,000km term. Don't worry, I would have changed it myself even if the dealer hadn't.

The general consensus here on the forum seems to be that this is a DPF or DPF sensor issue. The engine does not rattle at all, starts first time 99% of the time, pulls well and has never gone into limp mode – ever. There is no tow hitch so the car has never towed. It's also automatic so less likely to have been “thrashed”. I have had the usual “Soot particle full messages” and I have had “Engine system service required” messages twice. I was told the ESSR messages generated codes pertaining to deteriorated oil quality. On both occasions the oil was changed as a result.

I'm very keen to get myself a code reader. I'll do some homework here before I buy and try and get a really good one.

The engine warms up quickly and the temperature gauge never moves from (I think it's the halfway position), even when the weather goes into “stinking swamp mode”. In summer we sometimes see temps of 40 degrees plus.

My warranty expires in 8 days which is why I’ve been trying so hard to get the dealer to sort this problem. The latest dealer feedback (late this afternoon) goes something like this....

Dealer says there is no evidence that there is a problem with the DPF or the sensor as the ECU has logged no faults to that effect.
They say the car is running particularly “clean” - way below acceptable limits. They have now changed an oil pressure sensor. Apparently there are 2 types. One with 2 wires and one with 3.
If I’ve got this right, it is suspected that the oil pressure sensor is on the same “wire or line” as the DPF sensor and could be confusing the ECU and causing unnecessary “regens”. I've never read anything to this effect on any forum but then I haven't read all the threads either.
I don't really know what to say to this. The dealer did say that the guy who proposed this theory has 9 years of experience with Volvo.
I'm just so tired of all this. I just want the car to be able to do the specified 10,000km between services without error messages and without committing mechanical suicide. Surely this is not too much to ask?
Finally, I’m reading more and more about DPF limitations and am inclined to agree with you – they really do seem to be more trouble than they are worth. In fact I’ve seen entire websites devoted to their eradication.

[skyship007]

Sorry to hear the dealer is not helping as they should. After reading those answers to the questions from Dieselfan, it must be a blocked DPF or one of the sensors connected to the exhaust system that feeds info to the ECU. An actual ECU fault would throw a specific fault code, so I agree with the Volvo dealer, that it must be a sensor, unless you have done so many short trips and spent so much time at idle that the DPF is blocked, which is unlikely.

If the dealer does not replace the sensors and / or the DPF, then copy everything to Volvo in Sweden and get them to sort things out by leaning on the SA dealer.

One other thought that did cross my brain cell, was that I don't know what this engine does if the EGR blocks. There might be a chance it would cause similar fault codes and trigger the Regen cycle. Have they looked at the EGR ?
If there is no odd lag when accelerating it's unlikely though.

Once you are out of warranty, I would not use the 0 or 5/30 Castrol Edge oil, as a full synthetic 0 or 5/40 C3 rated diesel oil would be better. Castrol Edge turbo diesel 5/40 for example would resist the effects of fuel contamination better and you live in a warm country, so using a slightly thicker oil with an older engine is better in my opinion (Manufacturers use lighter oils for fuel economy reasons).

Not sure what the dealer has listed for the max oil change interval, but if you want a diesel to last a long time (The turbo in particular), I would change the oil twice as often as the Volvo max figure. Dirty oil filters work better than clean ones, so I always change them at the max figure.

When you do a main service, it's worth sending an oil sample off to a cheap oil lab like Blackstone (They will send you a free sample kit). That cost 25 dollars plus the one way postage for a 200 ml bottle to Fort Wayne in Indiana. I send a sample every 10K km because of severe service issues (Heavy horse box towing and driver abuse, plus short tripping in winter) and it's one good insurance policy, as the Blackstone analyst will let you know what is going on with your engine and if the oil needs changing more or less often. They can even tell if your air filter does not fit or if there is a tiny hole in the head gasket etc.
Once the DPF and / or sensor is replaced, the target fuel contamination figure should be less than 2%, but if you are using a major brand full synthetic 0 or 5/40, 5% would not cause too much harm in the longer term. Blackstone will have a set of averages for the 2.0D, so that is also a good guide.

One odd thing, is that you say the dealer is doing 10K km services, the EU V50's are on at least 20K km services, so I wonder if that is due to dusty roads in SA. They do 10K km oil and filter changes in the mid East (Or less) due to dusty air. I would be very interested to see the Silicon figure if you get a UOA done. The average is about 15 ppm for 10K km, mine is currently 8 ppm (Nice efficient dirty filter) and the condemnation figure is 30 to 50 ppm according to engine type.

One final question, is that if you look in your handbook, in the oil section, does it list a 15/40 full synthetic C3 engine oil as the best for hot desert operations (It's a difficult oil type to find with a C3 designation)?

[5cilinder]

Oildillution is not lineair when the dillution % rises also the vaporisation rate increases (only dinodiesel,biodiesel will remain in the sump due to very high vaporisation temps)
So after 8000km its not 20% but less



Now the dillution is up to 10/20% bearable ,First you need to drop the 0w30/5w30 oilspecification ,dont listen to volvo brainwashed sheep that volvo knows better blaa bla etc
When they made those specifications they even didnt knew that there was oildillution due to the dpf when they were introduced , so they diskwalified for advice in this matter
So compensate for oildillution by using a thicker oil with better hths strength
Filmstrength at 150 c
Take a good synthetic low saps 5w40/50 another benifit is that they are generaly cheaper
What you can do is to also shorten the drain intervals , this is besides inconvenience never bad or pul halfway the draininterval some oil out with a pelapump so that the dillution percentage drops after refilling
Other options are not possible because the regeneration will dillute the oil its inherent with the system
Small benefit to diesel dillution is that diesel acts as a solvent so engines are generally very clean and if dillution percentages are not too high it wont damage diesel lubricates better than gasoline (take them between the fingers at the same time left diesel right gasoline , diesel feels "oily" )
Ive a high mileage dpf engine and the compression is still very good , and the camshaft looks new

[skyship007]

Originally Posted by 5cilinder

Oildillution is not lineair when the dillution % rises also the vaporisation rate increases (only dinodiesel,biodiesel will remain in the sump due to very high vaporisation temps)
So after 8000km its not 20% but less



Now the dillution is up to 10/20% bearable ,First you need to drop the 0w30/5w30 oilspecification ,dont listen to volvo brainwashed sheep that volvo knows better blaa bla etc
When they made those specifications they even didnt knew that there was oildillution due to the dpf when they were introduced , so they diskwalified for advice in this matter
So compensate for oildillution by using a thicker oil with better hths strength
Filmstrength at 150 c
Take a good synthetic low saps 5w40/50 another benifit is that they are generaly cheaper
What you can do is to also shorten the drain intervals , this is besides inconvenience never bad or pul halfway the draininterval some oil out with a pelapump so that the dillution percentage drops after refilling
Other options are not possible because the regeneration will dillute the oil its inherent with the system
Small benefit to diesel dillution is that diesel acts as a solvent so engines are generally very clean and if dillution percentages are not too high it wont damage diesel lubricates better than gasoline (take them between the fingers at the same time left diesel right gasoline , diesel feels "oily" )
Ive a high mileage dpf engine and the compression is still very good , and the camshaft looks new

Good we agree on the Volvo spec engine oil. One question I have for you, is which engine and oil temp is that graph for ?
I've seen a lot of UOA results and have never seen more than 5% diesel in the oil from a DPF equipped car, although most folks taking an oil sample do it between Regen cycles to get an average figure. The only cars with DPF's that seem to return more than 2% are stuck in traffic or doing short trips where the oil does not warm up much before they switch off.
If the OP is in SA he might not get much choice about which C3 rated oil to use and importing anything would be expensive, but there will be some synthetic x/40's around. If the OP does decide to use another type of oil, it's worth checking the actual viscosity figures in the data sheets available from major brand oil company web sites. The 40 grade is a range and some oils like Mobil 1 0/40 or Shell Helix Ultra 5/40 are rather low in the 40 range, so it would be better to use a mid or high 40 grade one. Castrol TD 5/40 C3 is fairly well up in the range and that oil is normally easy to find.

PS. If you do get a UOA done, it might show a flashpoint out of limits warning, rather than a fuel contamination one. It would be real interesting to see the present results, as I've never seen a report with so much fuel in it. I wonder what the Lead and Iron figures are like.
If you do short trips with a modern diesel, fitting a simple stick on sump heater (250W) reduces the warm up time a lot in winter and saves fuel. It also helps the fuel evapouration rate and helps prevent EGR/Cat/DPF clogging deposits. They are not too expensive and easy to install.

[5cilinder]

That graph isnt a perfect practical example , because this was dilluted for hours in one go
Normally its 15 minutes regeneration in 400 miles or so
Ive seen a graph with a car on a testbench the dilution was a flattened out curve when the dillution became 15 % coulden't find it do to link it
The temp in the graph used above is 85c its in red on the right

Sumpwarmup isnt needed this engine has a coolant oil heat exchanger sot roughly the coolant temp is also the oiltemp
So even if you warmed up only the sump the heatexchanger will cool it quickly down to the at first cold coolanttemp
If you want to heat something get a coolantheater , also availible from volvo or aftermarket ,then the oil is also instantly heated the moment the engines runs

[chrisdc]

Hi skyship007,

Thank you for your contribution, you have raised some interesting points. The EGR was my prime suspect after joining this forum and reading lots of threads on the subject. Over time, the focus seems to have shifted to the DPF, but now that you mention it, I wonder if it's not worth removing the valve and having a look. I couldn't do it at the time without invalidating the warranty. My girlfriend used to drive the car during the week and she'd complain about hesitation (or lag as you put it) when accelerating. I also noticed it but it seems to have improved and Volvo did replace a turbo pressure sensor, so perhaps that had something to do with it.

As far as using a thicker oil goes, I'm inclined to agree with you, and others on the forum have suggested it too. There is a viscosity chart in the owners handbook listing SAE 0W-30, 0W-40, 5W-30 and 5W-40. The recommended oil for the 2.0D is SAE 5W-30 (grade WSS-M2C913-B). I see no reference to C3 anywhere in the book. (or any other grades of oil)

I read with interest your comments about dirty filters (both air and oil) filtering better than clean ones. I will do as you suggest and change the oil twice as often and the filters when specified.

I read also with interest, your comments on Blackstone. My last oil sample was sent to a local company called Wear Check (may be one word). I will ask for a copy of the report when I collect my car and post it here in case anyone is interested. Thank you for the suggestion.

As far as service intervals go, companies like Citroen have 30,000km service intervals, even for diesel cars, here in SA. Same country, same dust, so I’m not sure why Volvo chose 10,000km. There is a time interval specified too, usually 1 year or the specified distance, whichever comes first.