Does fuel dilution keep engines clean?

Oliveoil2 said:
I’m wondering what others think. It seems to me that a little fuel 1-2% actually helps keep an engine clean of deposits. For instance, I’m looking forward to seeing a valve train pick of a Honda 1.5t with 200-300k.
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Can't say 200-300k miles but I got one with 120k and a blown headgasket.

IMG_20241227_090214_527.webp
 
Nessism1 said:
Bummer! I'm way more concerned about a blown head gasket, than oil dilution. For reasons, I don't understand, the Accords seem to suffer far more blown gaskets than the Civics.
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The head gasket failures have been more frequent, than internal engine problems, on the 1.5 engine.
The thing I find "interesting", is the turbo failure rate has not been a big problem.
Turbos don't tend to do well, without a good oil/lubrication supply.
 
Nessism1 said:
My favorite youtube channel, "I Do Cars", has the owner of a salvage yard doing engine teardowns, and one of the telling signs of how the engine is wearing involves camshaft wear. Roller camshafts commonly do well, but not all. And the cams in that 275k mile oil diluting engine look quite good. Dismiss if you like, but to me, it represents an engine that's wearing well for the mileage, despite the engines diluting tendency.
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I would say any engine that clean on the top at 275K likely would have normal wear. I saw his post over on that forum - be cool to get a bit more info...which oil? What OCI? Any oil consumption? Leak down results? Compression results? I suspect they are all completely normal and the engine would show normal wear if you tore it down but yeah, hard to say but really...who cares? At 275K he got his money out of the car and it lasted well beyond what most folks see.
 
Sandstorm

Thread 'Oil Fuel Dilution, the Russian perspective'

Fuel Dilution, being a topic of interest to me, I have had the chance to communicate with Dr. Mikhail Zlenko, PhD of Central Scientific Research Automobile and Automotive Engines Institute (NAMI) in Russia.

His response to my question of "how much oil fuel dilution do you think is too much" put me at more ease. Often time we discuss UOAs with flagged dilution levels and get concerned about those levels and it's good to see a different perspective.

Screenshot_20240405_210656_Gmail.jpg
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Nessism1 said:
One piece of data rarely "proves" anything. I found the condition of the engine "interesting" (to quote Mr. Spock), considering the known diluting tendency of the Honda 1.5T, and the high mileage.

As I've mentioned in other threads about the 1.5T, yes, it dilutes, but with reasonable care, the dilution can be managed easily enough. Blindly following the maintenance minder, doing 10,000 mile oil changes, is not the way to go with this engine (my opinion).
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Probably ran a 20wt also. Hondas are junk
 
Nessism1 said:
The lobe on the right looks normal, but the left has what could be pitting, which if true, is not good.

I've messaged the dude on CivicX asking for info on oil used, oil change interval, and current mileage. If/when he replies, I'll update here. He did mention that the valves were pretty close to spec, after being checked for the first time at 275k miles.
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Yes looks like some excessive wear. Ready to take your point that you didn't make back yet?
 
Sandstorm said:
Sandstorm

Thread 'Oil Fuel Dilution, the Russian perspective'

Fuel Dilution, being a topic of interest to me, I have had the chance to communicate with Dr. Mikhail Zlenko, PhD of Central Scientific Research Automobile and Automotive Engines Institute (NAMI) in Russia.

His response to my question of "how much oil fuel dilution do you think is too much" put me at more ease. Often time we discuss UOAs with flagged dilution levels and get concerned about those levels and it's good to see a different perspective.

Screenshot_20240405_210656_Gmail.jpg
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Click to expand...
Depending on the load an engine can operate for tens of minutes with no oil. So no failure in several hours with severely diluted fuel seems quite achievable.
 
350Rocket said:
Yes looks like some excessive wear. Ready to take your point that you didn't make back yet?
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The engine has 275,000 miles on it. That small amount of pitting, if it's actually there, and not just the photo, is not "excessive" for an engine of that mileage. What's your point?
 
Nessism1 said:
The engine has 275,000 miles on it. That small amount of pitting, if it's actually there, and not just the photo, is not "excessive" for an engine of that mileage. What's your point?
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I don't think anything can really be learned without some samples of similar age without dilution to compare to.

It's a functioning engine that may or may not be worn more than it needed to be.
 
Nessism1 said:
Bummer! I'm way more concerned about a blown head gasket, than oil dilution. For reasons, I don't understand, the Accords seem to suffer far more blown gaskets than the Civics.
Click to expand...
Yeah, this thing has basically been a lemon since I got it. Had it for 40k miles and in that time its needed all the injectors replaced, the brake booster, a few months later coil failed. I just recently gave it a full tune up replacing the ignition side of the car and days later car just over heats and blown head gasket.

This has honestly been one of the most unreliable vehicles I've ever owned. I drive 54 miles one way to work, I put about 550 miles a week on this car, kept up with the oil religiously and just nothing but problems just down every couple of months. Warranty has covered most of the repairs but the head gasket fell out of warranty.
 
My poi
Nessism1 said:
The engine has 275,000 miles on it. That small amount of pitting, if it's actually there, and not just the photo, is not "excessive" for an engine of that mileage. What's your point?
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My point is that this picture doesn't prove that fuel dilution is not a problem. This engine with such high mileage has probably not been short tripped, meaning fuel dilution probably wasn't even a problem on this car.

I'm at 270k miles on my 20 years old work truck and it would be devastating to me if it failed right now. Some people are acting like 275k miles in a very short period of time is a major major accomplishment. The cleanliness of that engine just tells us that oil changes were done frequently enough.
 
350Rocket said:
My poi

My point is that this picture doesn't prove that fuel dilution is not a problem. This engine with such high mileage has probably not been short tripped, meaning fuel dilution probably wasn't even a problem on this car.

I'm at 270k miles on my 20 years old work truck and it would be devastating to me if it failed right now. Some people are acting like 275k miles in a very short period of time is a major major accomplishment. The cleanliness of that engine just tells us that oil changes were done frequently enough.
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The wall gets it!!
 
3800Series said:
.. car just over heats and blown head gasket.
Click to expand...

Perhaps you already saw this



Couple sources mention this

Use High Octane Fuel: For turbocharged engines, using higher octane fuel (91 or above) can help reduce the likelihood of Low Speed Pre-Ignition (LSPI) and knock, which can contribute to head gasket issues
Proper Tuning: If you're tuning your car, ensure that the tuning is done correctly to avoid increasing combustion pressures that could stress the head gasket
 
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