Honda’s Oil Dilution Issue

[Jpierro79]

This problem comes down to factory tuning. Manufacturers will enrich the fuel to bring down burn temps to keep from destroying catalytic converters. Driving differently like someone stated will not resolve a tuning issue. What happens when the fuel mixture becomes to rich it washes down the cylinder walls removing the oil film and it passes the piston rings. Some fuel always gets by but it less amounts. By flashing a new tune and fixing mixture it resolves the issue.
Oil contamination by gas was a common issue for old carburetor cars.
Many direct injection cars can run leaner safely.

Sponsored

 

[djhartm]

Delusion? You might be referring to dilution.

It is common in a DI engine.

There is so much misinformation in this thread...

It most certainly is not common on DI engines.

It most certainly was not common on carbureted engines.

Honda has a limited release fix, and there has been a lawsuit settlement for affected owners.

My 2018 1.5L and 2019 2.0L turbos both exhibit this (the 2019 to a much lesser extent).

 

[zspeed]

It most certainly is not common on DI engines.

Direct injection engines - where the fuel is pumped at extreme pressures directly into the chamber - are more susceptible to oil dilution. Engines that do lots of cold starts and lots of stop-start driving are more susceptible. Lots of heavy acceleration: More susceptible.

https://autoexpert.com.au/posts/engine-oil-diluted-with-fuel-the-facts-for-2018

 

[Hlee]

Who’s Civic SI Has The Oil Dilution Issue ?

I've read the oil dilution in DI motors might be regional dependent. If you live in an area that is mostly cold the oil dilution will be more apparent than warmer climates. I live in California and own a 2018 si and I do not have an issue with oil dilution. I've also read that if have a oil dilution issue you should let the vehicle warm up in the cold mornings during startups to burn away any fuel that might pass through the rings and into the dump.

 

[zspeed]

I've read the oil dilution in DI motors might be regional dependent. If you live in an area that is mostly cold the oil dilution will be more apparent than warmer climates. I live in California and own a 2018 si and I do not have an issue with oil dilution. I've also read that if have a oil dilution issue you should let the vehicle warm up in the cold mornings during startups to burn away any fuel that might pass through the rings and into the dump.

Warming it up for a short time will do as stated:
”Honda says the problem occurs when the engine doesn’t warm up enough to evaporate unburned fuel that slips past piston rings and infiltrates engine oil. The automaker notes oil dilution is normal in all internal-combustion engines, but especially in direct-injected turbocharged engines”.
https://www.wardsauto.com/engines/honda-15l-engine-suffers-cold-weather-oil-dilution-problem

 

[Design]

This is how much excess oil I just sucked out of my crankcase. This is a 1L bottle. The white on the surface of oil is just some odd looking reflection. The oil looks dark in the bottle, as Mobil 1 will, but it looks quite clear on the dipstick.

This is exactly a fortnight or 293 miles worth of oil dilution since the oil change. The exact corrected estimate (taking into account a slight difference between the original fill level and final level after sucking out), is just about 300 cc or almost 1/3 qt excess oil which is equivalent to about 6 mm oil level rise (each millimeter on the dipstick is roughly 50 cc of oil.)

So why so much in so litle time, during the hottest weather of the year with temperatures exceeding 90 F? And I don't do any trips that wouldn't allow the engine to fully warm up?

I have to assume it's because during these two weeks I had the compressor replaced by dealer. I imagine they idle the engine perhaps for hours as they refill and test it.

Also, the vapor pressure of the fuel in oil will increase with it's concentration. So the more diluted the oil, the faster it will evaporate, until the evaporation rate equals the dilution rate and the process should should stop at some level.

I suspect there could be something else going on with your powertrain. As you know, I just had my Si serviced for the evaporator and condenser. I essentially picked up my car, drove 3 miles to the station and checked the oil during a routine fillup in 73* weather. Result showed less than 1 mm above the fill line.

Any codes or other symptoms?

 

[Gruber]

I suspect there could be something else going on with your powertrain. As you know, I just had my Si serviced for the evaporator and condenser. I essentially picked up my car, drove 3 miles to the station and checked the oil during a routine fillup in 73* weather. Result showed less than 1 mm above the fill line.

Any codes or other symptoms?

No symptoms, runs great. What would show any codes? I would be rather surprised if I had an issue with with fuel injectors, after 14,000 miles of running mostly the fuel which is most advertised on the market for superior cleaning. Do people have early injector issues?

I'm still experimenting and the rates of (what should be called) oil dilution seem to be hard to figure out, but hope I'm getting there.

 

[PhilF]

The only way to really know is UOA, I send a sample to Blackstone every 5k mi when the oil is changed. Worst was one winter sequence with 2%, all the others are consistently under .5%. I use Mobil1 0W-20 AFE and M110A filters. Wear and particulates are very low and I've never added oil between changes. Did some reading on various websites including Mobil on the new GF-6a rating for this oil, very interesting, apparently the oil I'm using has met that standard for some time. Officially, every oil has to meet the new standards in May. This, combined with Toptier fuel and some sensible things, like not "warming" the engine up, giving the engine some highway time to allow oil to reach operating temperature on a regular basis should, unless there's genuinely a problem with the engine management/injectors, should at least keep this issue under control. The small displacement, direct injection, Turbocharged engine is a set of compromises to achieve adequate power, reduce emissions and increase mpg while simultaneously providing a reliable & durable powerplant. You've at least got to be aware of how this all works to deal with it, a regular UOA helps me to know what my engine is ACTUALLY doing. Sorry, the MM built into the car is a set of algorithms & averages, doesn't tell you a thing about dilution, wear, or remaining TBN, I'll continue the 5k intervals based on what I see from Blackstone.YMMV, I'm now at 26,000 miles.

 

[Gruber]

The only way to really know is UOA, I send a sample to Blackstone every 5k mi when the oil is changed.

In my circumstances and those of many other civicx owners, and as far as oil dilution itself goes, UOA is not the only way to know oil dilution, and not even the best one.
Of course UOA is the only way to early detect excessive wear, but I'm not concerned about that.

Assuming the relatively new engine does not burn or leak oil, the best and the most accurate way of measuring oil dilution is to measure oil level rise, or oil volume increase as I've described above. Neglecting small volumetric effects of mixing gasoline + oil, it gives the actual oil dilution percentage, which in my case was about 8.5%.

Now, this is the % of oil dilution, but it does not mean the oil is diluted to this % of with pump gasoline. Obviously.

How come? Elementary. The most volatile fraction of the fuel has already almost completely evaporated. Btw. as it happens, the heaviest fraction that's harder to evaporate contains the most smelly compounds. But they do not degrade the viscosity as much as neat fresh gasoline at equal total content would. (I would also expect the ethanol to evaporate from motor oil faster than the hydrocarbons, but I haven't yet looked into the actual data on this.)

 

[PhilF]

I would surmise the UOA, at 5K intervals would only give you an average level of dilution, my 2016 EX-L was traded at 37,000 miles. I was totally in the dark on the dilution issues at the time, but did regular (weekly) oil level checks. Didn't ever notice rising oil levels and never smelled any gas odor. I followed the same oil change intervals as I currently do. After becoming aware of the dilution issues, on my 2019, I started doing the UOA, along with being more observant of levels on the absurdly designed dipstick. Even with the interval where dilution tested at 2%, never noticed a rise in oil level. The UOA's have shown a steady, decline in wear metals as the engine broke in. I think you're correct in that the UOA doesn't accurately reflect all elements of dilution, however they're a decent indication of overall engine health and how it's wearing as well as the performance of the particular oil in use. The reading I've done on GF-6a spec oils indicate that they may, at a minimum, mitigate some of the dilution issues, especially those related to LSPI which, even at very low levels, increases piston ring blow-by. I would seriously like to see Honda split the injection so that some of the fuel mixture washes the intake valves.

 

[Gruber]

With Blackstone, I would pay more attention to the hot used oil viscosity they are reporting, than their % fuel dilution numbers. Which may be more useful for diesel.

 

[Design]

No symptoms, runs great. What would show any codes? I would be rather surprised if I had an issue with with fuel injectors, after 14,000 miles of running mostly the fuel which is most advertised on the market for superior cleaning. Do people have early injector issues?

I'm still experimenting and the rates of (what should be called) oil dilution seem to be hard to figure out, but hope I'm getting there.

I would imagine an injector issue would eventually show up as a misfire. I do find it interesting that you're accumulating that much fluid in the crankcase. Might be worth doing an analysis just to see if it turns up anything interesting.

 

[vasilas432]

So is there issue to hotter climates too?

 

[Gruber]

I would imagine an injector issue would eventually show up as a misfire. I do find it interesting that you're accumulating that much fluid in the crankcase. Might be worth doing an analysis just to see if it turns up anything interesting.

I might send in a sample just for fun. Not of the last 2-week old oil I pulled out as described in post #40 above, but the last sample I still have.

I could try Oil Analyzers who use FTIR for oil dilution, but I'm afraid they might increase the wear numbers for any oil other than Amsoil.... in particular Mobil 1.....

Blackstone uses the flashpoint, which underestimates oil dilution, but in fact, it's all I need to know. I know my real dilution % anyway, the low flashpoint tells me the fuel is evaporating as it should, while the viscosity still tells the true story of how thin the oil really is....

 

[Gruber]

So is there issue to hotter climates too?

There is definitely the potential of oil dilution regardless of temperature. Even at temperatures reaching over 30 °C.

To continue my current observations, I saw almost 1/3 qt excess oil in 293 miles, (#40 ) and I thought the long idling related to the AC compressor replacement might have been responsible for the rather unusually high rate of dilution.

Now I drove another 202 miles since removing the oil to just below the top mark. This included one longer trip of over 100 miles, with going smoothly up and down the hills at moderate speeds, and than several miles of highway racing at high speeds and top accelerations with several WOT/almost-WOT pulls. The other half of the 202 miles were my usual moderate trips that generally don't exceed 20 miles. The oil level did not increase. If anything, it might have decreased by ~0.5 mm during these 202 miles.

The LTFT, which usually hovers around -7%, and goes even more negative with slow driving, stop&go and idling, returned to -3% at the highest elevations (2300 - 2800 ft). The Kcont reached over 0.6 after very fast driving at about 90 °F and then quickly after that came back to 0.49 on normal driving. (93 AKI Exon Mobil Super+ this time) I consider this completely normal behavior.

So I don't see anything wrong with the engine. It just apparently has to suck up some fuel until it can start evaporating it.

Sponsored