Oil Smells Like Fuel

[jeckyll]

@Tigerkf Imagine this place like a corner pub, where a bunch of guys hang out and have bickered about different things for a long time.

Now imagine, some guy walks in and asks a question, which sets of a new round of back and forth bickering. Not so much to do with the guy who asked the question, just sort-of how things are. Then imagine this guy having a bit of a melt down.

Not sure if it's 100% a perfect analogy, but maybe get a bit of distance, I don't think anyone was attacking you in this thread. Just seemed like some fairly normal 'forum-back-and-forth'.

 

[EricV]

Relax, you're new-ish here and haven't posted a lot, we don't know what you know or don't know. No one is thinking you're an idiot, we simply don't know your experience and background. For anyone that's not had a dry sump or semi-dry sump engine, it's easy to be concerned about the sight glass' oddities. It's not an 'issue', it's a characteristic of all dry sump engines.

My first dry sump engine bike, when I asked my mechanic what the sight glass was actually useful for, his reply was: "to see if the goldfish are still alive." He wasn't far off.

So, just for grins, tell us a little about yourself. Been riding long? Had a few bikes you loved, or a bunch as your needs/desires changed? When did you start riding? One of the reasons we suggest filling out the profile with some info is so you avoid people thinking you don't have any experience. Location, even state, gives context to your posts and allows others to offer more helpful suggestions, like a dealer they like in your area, or where to source something, etc.

 

[EricV]

There were a few helpful comments without then sarcasm and "better than thou attitude" so thanks for that. To the rest of you who insist on trying to appear as you are the smartest person in the room and that I'm a blooming idiot, learn some social skills! My concern is not the advice given but the manner in which it was given. It's amazing how people talk to others when hidden behind the veil of the keyboard. I would chock this up to the lack of social skills our kids learn today but I'm sure some of the people who posted are as old as I am so......

Just a couple of things in regards to your above comments. 'Tone' on the internet is all in the eyes of the beholder. Don't read between the lines, just read the lines. Assume no one intends negative things and you'll be a lot better off. If someone wants to say negative things, trust me, they will.

And as far as "hidden behind the veil of the keyboard" goes, that's sort of the pot calling the kettle black when you've not identified your location and locked your profile.

As to why the marks are on the sight glass, it's for reference. They don't equal a quart between the lines. The owner's manual outlines a very specific process for checking the oil level with the sight glass. You're probably about the 5000th person to not read the owner's manual about this and not realize that w/o following that specific process, the level will not be consistent in the sight glass. It's just a different system and requires a different approach.

 

[Don in Lodi]

At least the 5000th...

 

[WJBertrand]

I wonder if it’s just dirty injectors not closing completely on shutdown. This would let the pressure in the injector system leak down as raw fuel dribbles into the intake, past the rings and ultimately into the oil.


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[Alexander]

Few quick thoughts:

(1) The engine management systems I've worked with do not "supply power" to the injector. The injector is *always* supplied switched/fused power, and the ECU merely decides when to ground the circuit in order to fire the injector. Point is, it's easy to test if the ECU is "holding an injector open" with a digital multimeter / continuity test -- just make sure there's no continuity to ground on the ECU-side of the connector. But as others have said, this is very unlikely.

(2) It's more likely that the injector itself is leaking after key-off (pintle isn't seating correctly, fuel pressure bleeds off), or the engine is running excessively rich. The former is quite common in the automotive world, and is usually caused by dirty injectors. The latter is a serious issue, as it could wash down the cylinder walls and result in premature ring wear, and Eric V is sharp to note the warm up enrichment cycle. How'd the spark plugs look when you pulled them?

Unfortunately, I'm too new to this engine to say much more, as I've only owned it since March -- haven't torn into it enough yet.

 

[EricV]

I wonder if it’s just dirty injectors not closing completely on shutdown. This would let the pressure in the injector system leak down as raw fuel dribbles into the intake, past the rings and ultimately into the oil.

What you and @Alexander are suggestion is certainly possible, but with only 16k on the bike and located in the US, it seems unlikely. I think we are perhaps taking the false assumption that a significant amount of fuel is getting into the oil at this point. The bike runs fine, the PCV system will vent crankcase gasses into the air box, normally to be sucked back in while running. No hard starting, which to me, would be symptomatic of a wash down of the cylinder after shut down. Same with the bad coil, possible, but would usually show other symptoms and would be unusual for a low mile bike.

We need to wait and see what other info @Tigerkf shares with us to see if it points in a more specific direction.

 

[Alexander]

I think we are perhaps taking the false assumption that a significant amount of fuel is getting into the oil at this point.

Agreed, we can only respond to the information given.

Easy starting would be the piece of the puzzle that doesn't fit to me. Usually have to crack the throttle open to start a flooded engine.

My primary concern is explaining how to verify the issues being discussed -- even if they are not the cause, you should be able to prove it. Without testing, we're just shooting the breeze.
1) You can test ECU grounding as I described above.
2) Normally, I would test fuel injector bleed-off with a fuel pressure gauge on a car's fuel rail, but I've no idea if this bike has a schrader valve or fuel pressure sensor or what. Fuel pressure should hold for at least a few minutes after key-off. If it immediately rockets down to 0 psi, then that's usually a problem.
3) Rich conditions are very apparent with scanning tools -- O2 sensor data, long term fuel trims. But few people have access to that. Reading the spark plugs is one way.

 

[Sierra1]

Maybe his sense of smell is like my wife's. . . . she can smell a rat fart at a hundred yards. What smells bad/strong to him, maybe normal to everybody else.

 

[ballisticexchris]

Another possibility is gas was poured into the crankcase oil fill (by previous owner) in order to flush out the sludge. Using a 50/50 mixture of gasoline and detergent oil to clean the engine is a common practice. It is one of the first things I do to every new and used vehicle I get after taking delivery.

 

[Don in Lodi]

And oil is a petroleum product... just sayin'. I have yet to smell used oil that didn't have some sort of smell from combustion byproducts. And yep, there would be several other issues if a leakdown was happening. Measure the oil in, measure the oil out. It's long term diagnostics, but would be more informative than a sense of smell.

 

[Alexander]

If one's nose is not a sufficiently calibrated tool, perhaps an oil sample could be sent somewhere for testing to be certain?

 

[EricV]

Maybe his sense of smell is like my wife's. . . . she can smell a rat fart at a hundred yards. What smells bad/strong to him, maybe normal to everybody else.

Or maybe he's spot on and there is excess fuel in the oil. We simply don't know. Internet diagnosis is spotty at best w/o more detailed info.

 

[Tigerkf]

Ok, so now I've got more information, some from responses to this thread, which helped me make a final conclusion on this issue. I initially noticed this issue 1. due to fuel smell in the oil. Then I noticed the oil level changing in the sight glass, another 1. 1 + 1 = 2 or does it!?!?!? As it turns out it doesn't, if you find out one of those factors is not what you thought it was. Prior to owning the S10, I had no experience with a semi-dry sump (or whatever you call it). I did not know that the oil level in the glass would fluctuate so much. Someone eventually posted links to a thread relating to oil level fluctuating.

After reading this thread, I realized that the oil level was not a second 1, therefore my initial speculation that oil level was increasing was not necessarily true. I decided to monitor the oil over a longer period of time and see what happened. I left on a trip and monitored the oil daily. I noticed the oil fluctuations but there was no dramatic increase in oil level. The oil level changes were similar to those mentioned in the oil level thread.

My conclusion to this issue was; 1. The fuel smell in the oil was due to normal transgression of some fuel into the oil as explained to me by a friend who is a mechanic. and 2. The oil level fluctuation was just that which normally occurs on this bike.

Soooo, I'm glad to say that in the end everything appears normal once all the facts were discovered. Case Closed!