wemay
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Some are now starting to opine that the manufacturers are aware of this and it has been taken into consideration.
Opinion, is fuel dilution an overblown subject?
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I think it can be over blown IF we don't look at wear values first. People can overthink things and jump on the non-problem before looking at the complete picture. Words like OCOD, garbage this & that are examples that have no merit in my opinion. Ed
JHZR2
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I would tend to agree.
In some fringe application - say some super powerful sports car or maybe in some trucks where there is active dilution at low load and then it gets slammed with high, sustained load, there could be an issue. No different than the claims back in the day that certain fuel adds and cleaners would increase bearing wear as they washed down.
But I doubt this is any worse than any time in the past.
Valve deposits in DI engines are an issue. And one may see a few ppm of extra wear that may or may not be related (but we can assume it is). The fuel and oil should be readily mixed, which is better than moisture where it will emulsify or even have a second phase in the pan. The fuel may reduce viscosity a bit, and may change oxidation and sulfation rates somewhat, but does it make a longevity issue? Did people get long life out of carburated engines that diluted more readily? Are oils better/stouter?
Perhaps only time will tell us if there is an issue in real terms.
Interesting question to discuss.
In some fringe application - say some super powerful sports car or maybe in some trucks where there is active dilution at low load and then it gets slammed with high, sustained load, there could be an issue. No different than the claims back in the day that certain fuel adds and cleaners would increase bearing wear as they washed down.
But I doubt this is any worse than any time in the past.
Valve deposits in DI engines are an issue. And one may see a few ppm of extra wear that may or may not be related (but we can assume it is). The fuel and oil should be readily mixed, which is better than moisture where it will emulsify or even have a second phase in the pan. The fuel may reduce viscosity a bit, and may change oxidation and sulfation rates somewhat, but does it make a longevity issue? Did people get long life out of carburated engines that diluted more readily? Are oils better/stouter?
Perhaps only time will tell us if there is an issue in real terms.
Interesting question to discuss.
Certainly not overblown in the case of dpf equipped diesels.
Have seen engines grenade with less than 5k on them due to diesel contamination with the oil ending up like thick black vaseline.
Have also seen excessive wear to a camshaft and head due to fuel dilution. The engine had done 80k.
These were both caused by failed regenerations of the dpf.
I don't think it will be as big a problem with petrol engines as most manufacturers seem to take low mileage and stop start into consideration with 1yr oil changes.
Have seen engines grenade with less than 5k on them due to diesel contamination with the oil ending up like thick black vaseline.
Have also seen excessive wear to a camshaft and head due to fuel dilution. The engine had done 80k.
These were both caused by failed regenerations of the dpf.
I don't think it will be as big a problem with petrol engines as most manufacturers seem to take low mileage and stop start into consideration with 1yr oil changes.
I think it would be an issue with some vehicles on an individual use profile. But in general, probably a non-issue for most vehicles as they are generally used.
I hope all of you are right, that it won't turn out to be a major problem. If short OCIs will handle whatever problem it might be, then so be it; three oil changes a year with synthetic, as opposed to two a year with dino, won't break me.
I think it is overblown.
They used to add kerosene to the oil back in the day to thin it for starting in extreme cold weather.
What about all the people that use MMO? Some add a whole quart at a time and nothing bad happens. One quart on a five quart system would be 20%, to me it seems that would be about the same as 10% fuel dilution on a gasoline engine or 15% on a diesel.
I have heard of truck diesels "making" oil, i.e., the dilution rate being higher than the evaporation and consumption rates combined. When they are "making" a couple of quarts a day over a period of time is when their bearings get wiped out. I was taught that a big diesel that doesn't noticeably drop on the dipstick every so often needs to be checked for a leaking injector.
They used to add kerosene to the oil back in the day to thin it for starting in extreme cold weather.
What about all the people that use MMO? Some add a whole quart at a time and nothing bad happens. One quart on a five quart system would be 20%, to me it seems that would be about the same as 10% fuel dilution on a gasoline engine or 15% on a diesel.
I have heard of truck diesels "making" oil, i.e., the dilution rate being higher than the evaporation and consumption rates combined. When they are "making" a couple of quarts a day over a period of time is when their bearings get wiped out. I was taught that a big diesel that doesn't noticeably drop on the dipstick every so often needs to be checked for a leaking injector.
I think fuel dilution is quite common, especially in colder climates, and rarely seems to cause much of anything except BITOG uproar...
Originally Posted By: wemay
Some are now starting to opine that the manufacturers are aware of this and it has been taken into consideration.
Just got my first UOA done on my DI Ford motor, no fuel dilution to speak of. Will try out other DI motor next and see if exclusive short trips show anything on that car.
Some are now starting to opine that the manufacturers are aware of this and it has been taken into consideration.
Just got my first UOA done on my DI Ford motor, no fuel dilution to speak of. Will try out other DI motor next and see if exclusive short trips show anything on that car.
With the diesels, it is becoming more of an issue, primarily due to biodiesel blends. BD has a higher flash point and vaporization point. It can accumulate in the oil and not dissipate like traditional diesel does. I ran into a little of this over the winter months. Now that the warmer weather is showing up, my last sample did not show any.
I've read more than once that the Germans and the Russians actually poured a little gasoline into the crankcase in order to help their engines cold start during the Russian winters on the Eastern Front during the Second World War.
So, a little bit of gasoline in the oil from fuel dilution probably "ain't" gonna be killin' nothin'.
So, a little bit of gasoline in the oil from fuel dilution probably "ain't" gonna be killin' nothin'.
My opinion is that it flashes off quickly. Unless it somehow binds with the oil. Someone can do an experiment.
Heat a couple of beakers of oil. One with straight oil the other with 25% gas added. See if the diluted oil volume falls back to the undiluted after a bit of heating.
Heat a couple of beakers of oil. One with straight oil the other with 25% gas added. See if the diluted oil volume falls back to the undiluted after a bit of heating.
Originally Posted By: turtlevette
My opinion is that it flashes off quickly. Unless it somehow binds with the oil. Someone can do an experiment.
Heat a couple of beakers of oil. One with straight oil the other with 25% gas added. See if the diluted oil volume falls back to the undiluted after a bit of heating.
25% gas is a lot, is that safe?
My opinion is that it flashes off quickly. Unless it somehow binds with the oil. Someone can do an experiment.
Heat a couple of beakers of oil. One with straight oil the other with 25% gas added. See if the diluted oil volume falls back to the undiluted after a bit of heating.
25% gas is a lot, is that safe?
Originally Posted By: demarpaint
25% gas is a lot, is that safe?
Sorry, Can't make life idiot proof as much as we engineers try.
Try 10%
25% gas is a lot, is that safe?
Sorry, Can't make life idiot proof as much as we engineers try.
Try 10%
Originally Posted By: turtlevette
Originally Posted By: demarpaint
25% gas is a lot, is that safe?
Sorry, Can't make life idiot proof as much as we engineers try.
Try 10%
I'm not trying anything.
10% of gas in my oil is a problem, and will probably do a number on the bearings, along with a host of other engine parts, just giving it some time. No need for me to experiment.
Originally Posted By: demarpaint
25% gas is a lot, is that safe?
Sorry, Can't make life idiot proof as much as we engineers try.
Try 10%
I'm not trying anything.
Nick1994
$100 site donor 2024
I think it's definitely overblown. Some people on here talk about not letting your car idle for more than like 5 minutes because of fuel dilution. I believe it isn't a big deal, a buddy of mine has a brother who lives in Alaska, and during the winter him and many others fire up their cars and trucks for an hour before leaving the house to warm up, and actually don't shut it down if they go to the grocery store for an hour as well and then let it run if they're going to leave home again soon. At this rate and what I hear on BITOG by some people it sounds like the oil would be 50% gasoline (that's my own exaggeration BTW). This guys truck is a 97 Silverado with a 350 and like 250k miles, all original. Obviously not causing an issue.
Many people all over the world do nothing but short trip and rarely change their oil and still get 200-300k out of a car. I think we're overthinking it.
Many people all over the world do nothing but short trip and rarely change their oil and still get 200-300k out of a car. I think we're overthinking it.
When I was in the military, oil analysis on power plant diesel engine prime movers we had to change oil if fuel dilution hit 5%.
I think manufacturer take dilution into consideration. Problem is those who do not change oil - way over extend oil changes resulting in dilution or sludge depending on condition and how one treats the motor (i.e. extended cold idling, short trippers etc).
Now having my DD a DI motor, I drive 95% highway and still change oil/filter every 5k. It's still under warranty to, so I don't push it to 7.5k normal service - I also like it on the clock every 5k making it easy peasy to remember, and would never have to worry busting the 7.5k mark, plus shouldn't worry about dilution much. Plus using 5w-30 instead of 5w-20 in non-winter times, just in case..... well I sleep okay I guess.
I think manufacturer take dilution into consideration. Problem is those who do not change oil - way over extend oil changes resulting in dilution or sludge depending on condition and how one treats the motor (i.e. extended cold idling, short trippers etc).
Now having my DD a DI motor, I drive 95% highway and still change oil/filter every 5k. It's still under warranty to, so I don't push it to 7.5k normal service - I also like it on the clock every 5k making it easy peasy to remember, and would never have to worry busting the 7.5k mark, plus shouldn't worry about dilution much. Plus using 5w-30 instead of 5w-20 in non-winter times, just in case..... well I sleep okay I guess.
On older cars that had mechanical fuel pumps there was a failure mode that would literally pour gas into the crankcase. I don't remember of any engine failures caused by that.
Originally Posted By: turtlevette
On older cars that had mechanical fuel pumps there was a failure mode that would literally pour gas into the crankcase. I don't remember of any engine failures caused by that.
I don't know how far back you are going in history.
But on all the vehicles I've worked on with a mechanical fuel pump, there was a small hole in the bottom of the fuel pump housing which would allow the engine oil to drip on the ground in the event of a seal leak.
Much like the little weep hole in the bottom of a water pump housing, that would be a tell tale in the event of a water pump seal leak.
The actual chamber that housed the fuel pump diaphragm, was separated by a gasket.
If the diaphragm failed it wouldn't pump fuel properly and the engine would be unable to run. It would just stop, so not enough fuel would get to the carby anyway.
From memory.
I think if fuel ever got into the lower chamber from a mechanical failure of the gasket, then the fuel would simply run out of the drain hole in the bottom of the lower housing, and onto the ground. Not into the engine.
It was a long time ago, and lots of drinks since those days now.
On older cars that had mechanical fuel pumps there was a failure mode that would literally pour gas into the crankcase. I don't remember of any engine failures caused by that.
I don't know how far back you are going in history.
But on all the vehicles I've worked on with a mechanical fuel pump, there was a small hole in the bottom of the fuel pump housing which would allow the engine oil to drip on the ground in the event of a seal leak.
Much like the little weep hole in the bottom of a water pump housing, that would be a tell tale in the event of a water pump seal leak.
The actual chamber that housed the fuel pump diaphragm, was separated by a gasket.
If the diaphragm failed it wouldn't pump fuel properly and the engine would be unable to run. It would just stop, so not enough fuel would get to the carby anyway.
From memory.
I think if fuel ever got into the lower chamber from a mechanical failure of the gasket, then the fuel would simply run out of the drain hole in the bottom of the lower housing, and onto the ground. Not into the engine.
It was a long time ago, and lots of drinks since those days now.
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Originally Posted By: Lurgi
I've read more than once that the Germans and the Russians actually poured a little gasoline into the crankcase in order to help their engines cold start during the Russian winters on the Eastern Front during the Second World War.
So, a little bit of gasoline in the oil from fuel dilution probably "ain't" gonna be killin' nothin'.
It was the normal practice to put 10% KEROSINE into the engine oil by volume, to get a thin enough(pumpable) oil.
It was normal practice back in the 50's as well as earlier times, for the colder winter climates in the USA, and all over the world.
There weren't any multi grades back then, and they had to chose between straight 40's, 30's and 20's depending on the ambient temps the vehicle was running in.
If one needed thinner oil for the extra cold, one simply added the 10% of kerosene to thin the straight 20 grade out to make the engine able to crank to start.
When you think about it, it's not like they were going to be running the engines hard in the depths of winter anyway, so no need for the thicker oils for protection.
And there was no multigrade oil alternatives.
On this forum some time ago, I recall seeing a picture posted of an original sticker (or riveted placard?) located on the firewall of an old Hudson.
It set it out in plain English, what oil grade to run or (the 10 % KEROSINE blend) depending upon the ambient temps.
I've read more than once that the Germans and the Russians actually poured a little gasoline into the crankcase in order to help their engines cold start during the Russian winters on the Eastern Front during the Second World War.
So, a little bit of gasoline in the oil from fuel dilution probably "ain't" gonna be killin' nothin'.
It was the normal practice to put 10% KEROSINE into the engine oil by volume, to get a thin enough(pumpable) oil.
It was normal practice back in the 50's as well as earlier times, for the colder winter climates in the USA, and all over the world.
There weren't any multi grades back then, and they had to chose between straight 40's, 30's and 20's depending on the ambient temps the vehicle was running in.
If one needed thinner oil for the extra cold, one simply added the 10% of kerosene to thin the straight 20 grade out to make the engine able to crank to start.
When you think about it, it's not like they were going to be running the engines hard in the depths of winter anyway, so no need for the thicker oils for protection.
And there was no multigrade oil alternatives.
On this forum some time ago, I recall seeing a picture posted of an original sticker (or riveted placard?) located on the firewall of an old Hudson.
It set it out in plain English, what oil grade to run or (the 10 % KEROSINE blend) depending upon the ambient temps.
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