Engine Oil Fuel Dilution Problem Is Back

[STS134]

The last time I changed the oil, the lab found very little fuel in it, and so this time, when I sent my sample in (at 6k miles instead of 5k), I asked them whether they thought I could go to a 10k mile OCI. Well this time, they found 4.5% fuel dilution, which is more than double what they found the first time (albeit that was only after around 3700 miles) and they basically told me no, don't do it.

It looks like the Outlander PHEV has big problems with fuel dilution in the oil reservoir, to the extent that it definitely makes the oil unusable beyond 7500 miles.

View attachment 18 OUTLANDER OIL ANALYSIS-30Sep2019.jpg

 

[Craigy]

To be fair, it only says that yours does, I would think a sample of more than one would be required to make that claim.
Also would think it makes a big difference on usage of the engine, and in this type of car this can vary much more than a traditional straight ICE engine.

 

[jaapv]

Weird that the large number of vehicles in Europe, which use a 20.000 km oil change interval, don't exhibit any abnormal engine wear at all. :roll: My car never exhibited rising oil levels on the dipstick and it has had six oil changes. 130.000 km.

 

[STS134]

To be fair, it only says that yours does, I would think a sample of more than one would be required to make that claim.
Also would think it makes a big difference on usage of the engine, and in this type of car this can vary much more than a traditional straight ICE engine.

First off, there are 3 sample points in that report, going all the way back to last year, and the values have been all over the map, from 2.0%, to a trace amount, to 4.5%. Hence my statement that the problem "is back".

Also, no one here is helping us get more data points. Why am I the only one who has posted oil analysis results? Why don't some others post their results so we can see if this is a consistent issue across all vehicles?

As I have said before, PHEVs tend to suffer from fuel dilution issues much more than pure ICE and HEVs. The oil doesn't reach operating temperature and stay there long enough due to use of the battery, which might result in a need for more frequent oil changes.

Weird that the large number of vehicles in Europe, which use a 20.000 km oil change interval, don't exhibit any abnormal engine wear at all. :roll: My car never exhibited rising oil levels on the dipstick and it has had six oil changes. 130.000 km.

How are these people determining that there's no abnormal engine wear? Generally, you will see elevated levels of metallic elements in the oil if that is happening. Or you have to open it up and look at the internal components. What did the lab results on yours say? That's the only real way you can determine how much fuel is getting into the oil. Because oil can burn or otherwise leak as well, and the two can offset each other. So, I'd be interested in seeing your lab report so we can compare.

 

[Steel188]

I can’t speak for the rest of Europe, but here in the UK, lab analysis of used engine oil is unheard of.

My average annual mileage for more than 30 years is 40,000pa, and I have driven cars from many brands. Most have been company cars but several have been my own where I have been paying all the bills, and it simply isn’t done here.

My PHEV shows 112,500 miles after 43 months. The ICE recently had the big 100k service and is in perfect working order. I am fastidious about checking the oil level every week, and it never changes. As for my battery, who knows? (Make that, don’t care).

I do recall a thread several months ago where the subject of synthetic oil was raised, and the matter of what passes as fully synthetic in the US was discussed. Here in Europe, we get true fully synthetic, but you get an inferior mix that doesn’t have the same properties.

You ask why the European contributors don’t post their lab results, well I suspect it’s the same reason I can’t -

 

[jaapv]

To be fair, it only says that yours does, I would think a sample of more than one would be required to make that claim.
Also would think it makes a big difference on usage of the engine, and in this type of car this can vary much more than a traditional straight ICE engine.

First off, there are 3 sample points in that report, going all the way back to last year, and the values have been all over the map, from 2.0%, to a trace amount, to 4.5%. Hence my statement that the problem "is back".

Also, no one here is helping us get more data points. Why am I the only one who has posted oil analysis results? Why don't some others post their results so we can see if this is a consistent issue across all vehicles?

As I have said before, PHEVs tend to suffer from fuel dilution issues much more than pure ICE and HEVs. The oil doesn't reach operating temperature and stay there long enough due to use of the battery, which might result in a need for more frequent oil changes.

Weird that the large number of vehicles in Europe, which use a 20.000 km oil change interval, don't exhibit any abnormal engine wear at all. :roll: My car never exhibited rising oil levels on the dipstick and it has had six oil changes. 130.000 km.

How are these people determining that there's no abnormal engine wear? Generally, you will see elevated levels of metallic elements in the oil if that is happening. Or you have to open it up and look at the internal components. What did the lab results on yours say? That's the only real way you can determine how much fuel is getting into the oil. Because oil can burn or otherwise leak as well, and the two can offset each other. So, I'd be interested in seeing your lab report so we can compare.

Well, if the engines - not one case reported- show no signs of excessive wear of wear with a fair proportion of the cars having run over 100.000 km up to much more, I think that is good enough for me. I wouldn't know where to get such a report done either. It is unheard of. If I asked my dealer it would produce uncomprehending to funny stares.
I do live in a harbour area. There is one laboratory in the country that does such an analysis - for marine engines in seagoing vessels. As I don't drive a Supertanker they would be rather surprised by my request. :roll:

 

[Craigy]

First off, there are 3 sample points in that report, going all the way back to last year, and the values have been all over the map, from 2.0%, to a trace amount, to 4.5%. Hence my statement that the problem "is back".

But it’s the same engine for all three samples, so still a sample of one unit, this is the claim I was referring to:

It looks like the Outlander PHEV has big problems with fuel dilution in the oil reservoir, to the extent that it definitely makes the oil unusable beyond 7500 miles.

And as others have mentioned there haven’t been any known issues.

Also, no one here is helping us get more data points. Why am I the only one who has posted oil analysis results? Why don't some others post their results so we can see if this is a consistent issue across all vehicles?

And as others have said this is totally alien to us here, nobody is going to do this.

 

[jaapv]

And it is not an issue, so certainly not consistent... :roll: This has a very high "the sky may fall" content to me.

 

[Woodman411]

I can’t speak for the rest of Europe, but here in the UK, lab analysis of used engine oil is unheard of.
...
You ask why the European contributors don’t post their lab results, well I suspect it’s the same reason I can’t -

I spent 30 seconds on Google and found this: https://www.lubemonitrix.ie/product-category/auto-mobile
Sorry I know Ireland is not part of UK, but I'm sure if you searched, there's got to be more around.

 

[Steel188]

I and others aren’t saying the service doesn’t exist here, it does and is easily found on Google, our point is that oil analysis is not something that is done on this side of the Pond.

We had a chat about this at work today, 6 people (ranging from 24 to 63 years old), all with different cars, 2 of whom came from a company that manufactured machines to test the performance of diesel engines, and not one of them had heard of this kind of thing and don’t feel the urge to find out either.

 

[jaapv]

I can’t speak for the rest of Europe, but here in the UK, lab analysis of used engine oil is unheard of.
...
You ask why the European contributors don’t post their lab results, well I suspect it’s the same reason I can’t -

I spent 30 seconds on Google and found this: https://www.lubemonitrix.ie/product-category/auto-mobile
Sorry I know Ireland is not part of UK, but I'm sure if you searched, there's got to be more around.

Who in his right mind is going to spend an extra 65 or 81 quid per oil change when it is clear that the engines are doing perfectly fine on the factory-recommended interval?
Besides, I prefer to have my car serviced in my neighbourhood, not in Ireland. The only two over here that showed up on Google cater to Caterpillar marine and industrial engines.
BTW, if you read further on the site you linked to, you'll find that they recommend the use to garages who want a "forensic" check in case of problems. (read their case histories)

 

[ThudnBlundr]

Just because you can measure something doesn't necessarily make it worth measuring, or something you should focus on. Look at government targets, most of which seem to drive wrong or unpredictable behaviour...

 

[Woodman411]

I and others aren’t saying the service doesn’t exist here, it does and is easily found on Google, our point is that oil analysis is not something that is done on this side of the Pond.

We had a chat about this at work today, 6 people (ranging from 24 to 63 years old), all with different cars, 2 of whom came from a company that manufactured machines to test the performance of diesel engines, and not one of them had heard of this kind of thing and don’t feel the urge to find out either.

Yet the most common car questions are "how often should I change my engine oil?" and "is fully synthetic worth it?" These answers are unique for each vehicle and driving condition, and in the long term, the costs can add up depending on frequency and type. And in this particular forum, due to the PHEV's unique characteristics, even more so.

 

[STS134]

Who in his right mind is going to spend an extra 65 or 81 quid per oil change when it is clear that the engines are doing perfectly fine on the factory-recommended interval?
Besides, I prefer to have my car serviced in my neighbourhood, not in Ireland. The only two over here that showed up on Google cater to Caterpillar marine and industrial engines.
BTW, if you read further on the site you linked to, you'll find that they recommend the use to garages who want a "forensic" check in case of problems. (read their case histories)

Say something happens in your engine that causes increased wear. You'd be able to see a sudden increase in say the aluminum or copper content of the oil and you'd instantly know that something was thrown out of whack, but only if you have the data from when the engine was operating normally. Then you'd know it was out of character for this engine.

In my previous vehicle, I told the dealership that I had an oil leak. They asked how I knew. I said, because the oil level dropped by about 1 quart in 5000 miles. They said that's normal, and well within the specs for this engine. I told them yes, that's true, but this engine doesn't burn detectable amounts of oil. So they opened it up and found oil leaking from around the timing chain tensioner. If I didn't have the data points from previous oil changes (say I had just bought the car used), this issue would have gone undetected.

Why would you want to not gather the data, let problems go undetected, and then end up paying more in the long run because you didn't spot the problems earlier? Look at the TBN values in my samples. At 3.7k miles, it was 5.0. At 5k, it was 4.5. By 6k miles, it had dropped to 2.9. This kind of gives me an idea of how long I can run the oil. 7.5k miles max I would say, since TBN needs to be > 1.0 and in any case it looks like fuel dilution is also a limiting factor. Say I run this out to 7.5k miles and they find TBN at 0.5 and increased levels of metal in the oil. That tells me that I'd better go back to a 5k mile OCI.

Yet the most common car questions are "how often should I change my engine oil?" and "is fully synthetic worth it?" These answers are unique for each vehicle and driving condition, and in the long term, the costs can add up depending on frequency and type. And in this particular forum, due to the PHEV's unique characteristics, even more so.

That's the thing, we don't have very much data on what happens to oil in PHEVs. My friend got a Cayenne S E-Hybrid, and the first time he pulled oil and had it analyzed, the lab found shocking levels of fuel dilution in the oil. We suspected it had something to do with engine operating time and oil temperatures, so when I got my PHEV, I pulled oil when it had just 3.7k miles on it and they found exactly the same thing. So this appears to be a general pattern that we're seeing with data points from two cars, albeit different models. The fuel dilution issue in his car seems to be even worse and we think it's because it has an 8 quart oil reservoir that takes even longer to heat up to operating temperature.

 

[jaapv]

Well, after having driven well over 1.500.000 km in all kinds of cars without anything like that happening (well, I had to rebuild an MG engine that I bought with over 400.000 km and I once had a lemon Mini that needed three engines on guaranty within 50.000 km before I traded it in) I consider the money not spent on this well saved.

 

[STS134]

Well, after having driven well over 1.500.000 km in all kinds of cars without anything like that happening (well, I had to rebuild an MG engine that I bought with over 400.000 km and I once had a lemon Mini that needed three engines on guaranty within 50.000 km before I traded it in) I consider the money not spent on this well saved.

Who ever said the goal here was to save as much money as possible? Sometimes you just do something because you're curious about the results. I'm not sure if I'm going to continue doing this at every single oil change, but getting at least the first 3 or 4 before going to maybe once every 2 or 3 oil changes is a good idea.

 

[Steel188]

5k oil changes! Blimey, next you’ll be telling us we should use 4* petrol

The oil (proper fully synthetic) gets changed at the service interval of 12500 miles, with a weekly check to ensure the level hasn’t changed .............. again!

I can just imagine the conversation with my leasing company, if I said I’ve had the oil analysed, and I disagree with the vehicle manufacturer’s published servicing regime! I’m pretty certain it would involve men in white coats and a padded cell! :lol:

Let’s just accept there are cultural differences between us that make these exchanges interesting, frustrating and wonderful all at the same time. Peace.

 

[jaapv]

Who ever said the goal here was to save as much money as possible?

Actually, you did...

Why would you want to not gather the data, let problems go undetected, and then end up paying more in the long run because you didn't spot the problems earlier?

 

[greendwarf]

In the dim distant past, when I was too poor to own a newish car and/or pay for servicing, so did it myself, I always used flushing oil at every change but I am sure none of the commercial garages would have done! :lol:

Aside from this anecdotal debate does either side have any technical sources we can be referred to on the subject?

 

[elm70]

Interesting discussion STS134

I see, that every time somebody try to criticize the PHEV, he/she get questioned "hard"

Personally I have no idea how to get such oil analysis (I guess it is not part of any standard service, anywhere in EU) , as well .. I'm not sure at which level the presence of fuel can be critical for the engine.

What I know is that mileage and km between service in a PHEV is something very questionable ... in my case I'm using the ICE in my PHEV very rarely ... in the last 6 months possibly I never used the ICE, since for long trips I'm using a different car.

So change oil every 10.000 or 20.000km ... on a PHEV is much different then on a normal car. Based on the usage, the ICE might have run for 1.000 or for 85% of the km done ...

Assuming people do at least 50% of their trips in EV mode (else why get a PHEV ?) ... I think the oil change interval recommended by Mitsubishi are already very conservative

Our PHEV might have tons of defect ... but for what we did see in multiple years of ownership .. it is that the Mitsubishi conservative design help on making the car very reliable.