Does fuel dilution keep engines clean?

[Pablo]

Fuel is a solvent, so it should help “cleaning”

Raw fuel is not good, but as others have stated it's not an automatically a death sentence as some imply.
Partially burned fuel, oxidized fuel is a larger problem. It can overwhelm the anti-oxidants in oils, and indeed cause deposits - I think the picture above may show in this engine partially oxidized fuel is not hugely a problem.

Amsoil above linked and here does a great job: https://blog.amsoil.com/what-is-fuel-dilution-and-why-is-it-bad/?zo=515729

 

[tolian21]

Even amsoil knows fuel dilution is bad, but some people believe that Honda knows what they are doing, maybe they even designed engines for it

 

[D1dad]

Not sure if it’s cleans but it sure does make the oil dirty. At least in my wife’s new 24 Altima. I changed the factory oil to hpl at 1k, then changed it again at 6k. Now the car sits at 8500 miles and the oil is bordering on black in color. I know that “color means nothing”. Doesn’t mean I’ve gotta like seeing dirty oil. If that’s how this engines going to be then I’ll just run cheap oil and change it way more often. I can run any oil in our 18 rogue and it stays cleanish looking the entire time.

 

[Pablo]

Not sure if it’s cleans but it sure does make the oil dirty. At least in my wife’s new 24 Altima. I changed the factory oil to hpl at 1k, then changed it again at 6k. Now the car sits at 8500 miles and the oil is bordering on black in color. I know that “color means nothing”. Doesn’t mean I’ve gotta like seeing dirty oil. If that’s how this engines going to be then I’ll just run cheap oil and change it way more often. I can run any oil in our 18 rogue and it stays cleanish looking the entire time.

What % fuel?

Even amsoil knows fuel dilution is bad, but some people believe that Honda knows what they are doing, maybe they even designed engines for it

Even Amsoil????

Listen Amsoil knows quite a bit but in some respects Honda could fix the problems with remapping fuel management - I believe the turbo enrichment (oddly to protect the engine under boost) just is either too much (rich) and maybe too long.

Maybe shorter intervals help but I would be reluctant to run a low additive oil - knowing what partially burned fuel does to the additives.

 

[tolian21]

What % fuel?

Even Amsoil????

Listen Amsoil knows quite a bit but in some respects Honda could fix the problems with remapping fuel management

Maybe shorter intervals help but I would be reluctant to run a low additive oil

Thats what I am saying, multiple reputable sources say that fuel dilution is bad, but some Honda apologists try to say its normal.

 

[BISCUT]

Honda knows what they’re doing. Fuel dilution is a-ok imo. If it were so bad, we’d be seeing tons of Hondas broken down on the side of the road.

Honda had some difficulties with fuel dilution in the early years ...... Fuel Dilution is not "a-ok" IMO and needs to be mitigated with a quality synthetic and reduced OCI.

 

[Pablo]

Thats what I am saying, multiple reputable sources say that fuel dilution is bad, but some Honda apologists try to say its normal.

I get it, edited my post. Thanks.

 

[D1dad]

I say I’m going to run the whole OLM in my 21 and now 24. I always chicken out.

 

[Glenda W.]

After a second look it appears to have some cam wear. Or am I seeing things?

 

[Nessism1]

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.

 

[Glenda W.]

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.

Considering most never see 275k I wouldn’t complain.

 

[Mainia]

I had really bad fuel dilution in my Hyundai Kona 1.6T till I un jammed my rings. I live in Minnesota, my car is tuned and I am a short tripper. 10 miles to work. My worst amount of fuel gain was 1.5++ Qt in a 3,000 mile oil change. At about 1,200 miles I would take your classic oil sample pump and poly hose and suck out the gain through the dipstick tube. I would even have .75+qt in mid summer. I was monitoring wear at Polaris Labs. None was out of spec for that engine series.

I was running Amsoil, Mobil 1 ESP, Mobil 1 Extended at the time. I ran Redline Performance Euro 5w-30 one time and midway through the run I noticed I had no more gain. I even PMed MolaKule on what he thought at the time. My hypothesis now is my rings were jammed and as soon as they could start sealing the bore the dilution left. I kept running Redline Performance Euro for a couple years till they priced me out of the market. I am running Motul 8100 Clean Gen 2 for the last 2 years with a couple of Redline stash changes in between and HPL Engine Cleaner in the Motul every other to keep my ring lands clean.

And was not a HP fuel pump leak as I still have the original in my car and I can monitor it's resigual pressure on turn off of the engine with my Bank's iDash Gauge. At the time, Hyundai was installing a bunch of these HP fuel pumps in cars to no avail.

I now get about 1/8th to 1/4 qt dilution in the worst of winters and no dilution in the summer. Last year with very mild winter, I had the 1/8 qt rise.

 

[Mechanician]

Raw fuel is not good, but as others have stated it's not an automatically a death sentence as some imply.

This^
Also there are too many variables, to say the photo proves anything about fuel dilution.

 

[TiGeo]

 

[Nessism1]

This^
Also there are too many variables, to say the photo proves anything about fuel dilution.

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).

 

[JAG]

Increased Acidity​

• Fuel dilution can also increase the oil’s acidity, as the fuel can contain acidic compounds.
• A study presented at the JOAP International Condition Monitoring Conference found that fuel dilution can lead to a 50% increase in the oil’s acid number.
• Increased acidity can cause corrosion and damage to engine components, such as bearings and gears.

Reduced Detergency And Dispersancy​

• Fuel dilution can impair the oil’s ability to keep contaminants suspended and prevent the formation of sludge and deposits.
• This can lead to the buildup of harmful deposits on engine components, further contributing to wear and tear.

Decreased Oxidation Resistance​

• Fuel dilution can reduce the oil’s resistance to oxidation, which can lead to the formation of harmful byproducts, such as varnish and sludge.
• Oxidation can also cause the oil to break down more quickly, reducing its effective lifespan.

Source: https://techiescience.com/impact-of-fuel-dilution-on-lubrication/

The fuel that ends up in the oil survived the very high temperatures in the combustion chamber. That partially oxidizes it, making it a deposit precursor since partially oxidized hydrocarbons are highly reactive. I suspect any cleaning they could potentially do when “young” is more than compensated in the deposit direction by the “older” fuel-borne molecules.

 

[Mechanician]

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).

Agreed.
There are hundreds of thousands of these engines on the road with no major problems.

 

[tolian21]

“Thousands of these cars on the road without an issue”, Honda came up with something amazing that beats all the odds!

 

[Astro14]

I'm not contradicting anything. Do I need to mention excess wear in every follow up post I make?

A person posted about fuel dilution leading to oil film break down, and another person mentioned deposit formation.

I simply posted a photo, showing no unusual wear, and no deposits, on a known oil diluting engine with 275k miles. Your posts here are blowing up the discussion. There is no reason for it.

Again - your photo fails to support your point, it does not show the absence of wear, unusual or otherwise.

You are the one “blowing up” the discussion by defending this photo.

I’m not arguing your point, I’m arguing that the photo fails to support your point.

It is a specious, pointless object in the discussion, and that kind of unsubstantiated argument is what blows up discussions.

 

[Nessism1]

Again - your photo fails to support your point, it does not show the absence of wear, unusual or otherwise.

You are the one “blowing up” the discussion by defending this photo.

I’m not arguing your point, I’m arguing that the photo fails to support your point.

It is a specious, pointless object in the discussion, and that kind of unsubstantiated argument is what blows up discussions.

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.