Fuel in oil (suspected)

[Forevertwowheels]

Hi everyone,

I noticed my oil level was slightly over the “full” mark a week ago. I thought maybe it was just an overfilling mistake from an oil change about 2,000 miles ago.  I drained a little bit to get it to a normal level and kept an eye on it since. It’s begun to rise slightly again. I suspect fuel is getting into the oil. Any suggestions on repair? I do not know how to test fuel injectors. Can I look at plugs and assume fouled plug is the leaky injector? I’m going to change the oil later today to see if I can confirm there is fuel in it. Hard to tell used oil and fuel smell pretty similar. 
 

thanks

[Forevertwowheels]

Update - I changed the (cold) oil on lunch today, no rainbow sheen in sunlight, no excess fuel smell, no abnormal metal or particles in the oil.  I saved half a quart in a clean glass jar to send to Blackstone labs for analysis.  I will keep an eye on levels until further notice.  Also going to do some research on levels variation of oil level in sight glass on this bike.  Fingers crossed its just me being neurotic as per usual.

[KrustyKush]

Ok, yes, I observed this on my 21GT. After an oil change. Eyeing the oil level for a couple days afterward, darned if the oil level didn’t climb in the sight glass just a mm or two.

It stopped rising, though. Stabilized. I figured this had to do with slight variations in bike position on my garage floor. The tilt, or off-level nature of it. Or maybe some other thing in the motor that was affected by alternating between side stand and center stand.

I decided it is a nothing burger. 

[nhchris]

On a recent oil change I drained the oil till it dripped and replaced the drain bolt and went to bed.  Next morning I was going to refill the crankcase but out of curiosity pulled the drain bolt first.

I was shocked when about 2-3 ounces of additional oil came out!

It takes a long time to fully drain the oil and if you refill immediately after a drain there will be a few oz in the engine that won't show up in the site glass until the bike sits for several hours.

I have overfilled my FJ by filling to the top of the glass immediately after a drain and then having the glass  show completely full later on.

Just say'n.

[2and3cylinders]

I used change the oil hot until a test by RRW convinced me to drain when cold.  I do it on the center stand, and let it drip overnight with the oil filler cap and filter not tight.  Sometimes before filling, I reinstall the old filter, drain bolt and filler hole cap then crank it over a few revs, remove the drain bolt again and remove the filter.  And yes another couple ounces eventually dribble out.

I fill gradually in increments for the last several ounces.  Overfilling is as bad as under filling slightly.  The oil level light will sometimes lite if you ride too soon after filling, and if it's a bit low.

Shell Rotella T6 5W-40 and a proper synthetic media filter...

[bwringer]

Good to know it's likely paranoia along with slight variations in angle, etc.

I swear having the engine visible makes motorcyclists fret and worry far more than with cars. And seeing oil level directly through a sight glass is different than using a dipstick, not to mention the smaller oil quantity makes for more variation with slight variations in angles.

In cars, and not so much motorcycles, it's also common to see rising oil levels in the winter in cars that are primarily used for short trips. Basically, water is a completely normal byproduct of combustion, and some ends up in the oil. All completely normal, and as long as the vehicle gets up to full temperature regularly, the water evaporates and the vapor is removed via the crankcase ventilation. However, in cold weather it's harder to get up to temp, people don't drive as much, and more water stays in the oil. The level of the oil seems to rise, and it's also common to see "mayonnaise" (a grody whitish water/oil mixture) under the oil cap, or even on the dipstick.

"Mayonnaise" visible in a motorcycle's sight glass is a fairly common panic-inducing sight on moto forums as the weather turns colder. Fortunately, the cure is a nice long vigorous ride...

Coolant leaking into the oil (in motorcycles, this is most often via failed water pump seals) can be another mayo-producer, but there are other symptoms.

 

Anyway, a leaky injector would likely create other symptoms besides gas in the oil, such as:

- One fouled plug, or one plug that's blackened compared to the others.

- Hard starting after a lunch or store stop; excess fuel leaks into cylinder and has to be burned off before that cylinder will fire.

- Strong fuel smell after the bike has been parked in a garage for an hour or so.

- Cloud of black smoke and/or fuel smell upon starting as it burns off the excess fuel. However, this will not be noticeable on a bike with a catalytic converter unless it's really, really excessive. 

- Weird exhaust smell from the catalyst struggling to deal with excess fuel and incomplete combustion. May be hard to notice. Can also cause the catalyst to overheat and melt if it gets really bad and is not corrected.

- Fuel pump running longer than normal when the key is turned on.

[Forevertwowheels]

Update: the oil level appears to be rising again. Slowly but surely. Same temp and position reads higher and higher til today there is no bubble at top of sight glass. I am pulling plugs this weekend to look for fouling or other evidence of injector issues. Blackstone labs test cup still has not arrived. Stay tuned. 

[knyte]

Yeesh, I sure hope it's not fuel.  That would be very unusual!

[KrustyKush]

Damn. This one will be interesting for sure. 

[skipperT]

Have you checked your coolant level? How is the color?

Does your fuel mileage seem worse than normal? 

How does the bike run otherwise?

-Skip

[texscottyd]

1 hour ago, skipperT said:

How does the bike run otherwise?

Thanks for asking, as I've been wondering the same.   My experience has been that a stuck/malfunctioning injector makes the bike run really badly, if it runs at all... 

Will be very interesting to see how this goes.

[skipperT]

45 minutes ago, texscottyd said:

Thanks for asking, as I've been wondering the same.   My experience has been that a stuck/malfunctioning injector makes the bike run really badly, if it runs at all... 

Will be very interesting to see how this goes.

Yeppers. You and I are in the same page, Tex. 
I’m doubtful about it being gas, and my hunch is that it’s coolant. 
-S

[peteinpa]

Get a long zip tie and take an oil sample from the oil fill hole and smell it. You'll know.

I check used cars all the time this way, but they have a dip stick.

If you pull the plugs look for a super clean one. There is your coolant leak (head gasket).

I seriously doubt you have either problem. 

I suspect the oil doesn't always settle the same at every shut down.

EDIT: would help to know where you live (for ambient temp.) How long you ride, etc.

Edited July 1, 2022 by peteinpa

[Forevertwowheels]

I haven’t ruled out head gasket (or internal wp leak) just yet. I have to say though the oil does not look or smell like it has coolant in it. I got the sample cup for Blackstone labs today so that’s off for results shortly. Plugs will be changed or inspected this weekend if I get the time. Thanks again to everyone for the input. 
 

quick edit:

I have had the collected oil sample from before sitting for a week in a hot garage and no separation has occurred. I’d imagine coolant and maybe fuel would separate after a week but I could be wrong. 

Edited July 1, 2022 by Forevertwowheels

[peteinpa]

Wait a second.  In your other post about leaking water pump you  said you pulled it and replaced it.

Can you do that without changing ANY seals???

Might be where coolant is getting into the oil.

How's the coolant bottle level??