10th Honda Civic Forum banner
1 - 6 of 6 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter · #1 ·
just purchased a 21 civic hatchback.. i didn’t know prior to purchasing about the oil dilution issue with this generation.. any thoughts? should i be concerned?
 

·
Registered
Joined
·
11 Posts
Depending on your climate it could be an issue so I would just check the oil periodically for a strong fuel smell. If it smells bad you could change it and perhaps have a sample tested for fuel dilution. I usually have my oil lab tested just because I'm crazy like that. My friends think I'm wasting my money but this is my first new car and I just want to know how it's doing.

Here are the lab comments at 8,500 miles(note that the fuel dilution is low but before this sample was taken I had to travel and drove 600 miles the day before I changed the oil and took the sample. And long drives will evaporate fuel out of the oil.): BRANDON: Thanks for the note -- it certainly never hurts to follow the maintenance minder's suggestions for when to change the oil. For a factory fill, this sample actually looks pretty good. Sure, there's some extra copper and silicon compared to averages (those are on the right side, showing typical wear after ~4,600 miles), but those are just brass/bronze wear-in and residual sealer, not a wear issue or contamination. Fuel dilution is always worth watching in these engines, but at 0.5% in this sample, fuel isn't indicating a problem. Check back for improvement next time.

16,500 miles: BRANDON: Before we get to the nitty-gritty of how your engine is progressing through wear-in, we'd like to discuss fuel in the oil. The flashpoint shows 1.8% of the sample is fuel, which isn't a cautionary amount, but these Honda engines can have issues with fuel dilution. If you notice a rising oil level on the dipstick, consider contacting the dealer. Idling or cold sampling could also explain this level of fuel. Now, as far as wear-in goes, your engine looks great. Metals and silicon are washing out and nearing universal averages. Repeat this interval and check back on fuel.

40,000 miles: BRANDON: Fuel dilution improved slightly this time, which is good news, but we'll continue to monitor it just to be safe. Wear metals held relatively steady or improved slightly, so it looks like parts are wearing well together, and the fuel dilution didn't cause any poor wear that we can see. The viscosity is in the correct range for 0W/20, and there's no other contamination such as coolant, dirt, or moisture to speak of. Insolubles are well below the 0.6% limit thanks to proper oil filtration. Aside from fuel this is a pretty good report, so we'll just see how fuel looks next time.

As you can see there is some fuel in the oil but I live in South Carolina and don't have many cold days and my car is garaged. People in the cold that let the car warm up and it runs rich longer will have a much different result. By the way I use Blackstone labs ( Blackstone Laboratories ) for my oil test, they will send you free sample kits and charge about $30.00 for a standard oil test and the results look like the attached if interested.
 

Attachments

·
Registered
Joined
·
11 Posts
As far as I know Honda changed how rich the engine runs in cold climates and how long the rich mixture lasts, but its an inherent design flaw. The problem is that the engine is direct injected not port injected. The injectors spray fuel mist directly into the combustion chamber and some of the fuel mist settles on the cylinder walls and gets mixes with the oil on the cylinder walls and is returned to the oil sump by the oil rings. This happens to all engines to some degree but is more of a problem with direct injection engines. But to your point Honda may have changed something else about the design in later years to limit the amount of raw fuel that sticks to the cylinder walls.
 
1 - 6 of 6 Posts
Top