WTH? Disappearing oil ...

[retro]

Need some wild specualtion, guesses, educated opinions, or past experience with this. I'm baffled.

The situation:

The bike leaves the house for the daily commute to work. Oil is at Full on the little crankcase window. Stop at friends house on the way home from the daily commute. Oil is nowhere to be seen in the little window. Pick up a panic quart of oil at a gas station and pour it in. Still no oil in the window. Get home, drive the cage to pick up 3 more quarts of oil. 2.75 quarts later the oil in the crankcase window is at full again.

24 hours later. Quick 100 mile ride. Arrive home and check oil. A full quart low.

The bike:

1989 Suzuki Katana 1100. Air cooled. 35k miles.

10 seconds worth of troubleshooting (which exhausts my entire repertoire of troubleshooting skills) shows:

Obviously check in parking spots for puddles. No leakage found in parking spots at home or at work. No leakage around any gaskets, oil filter, or oil plug. No smoke from exhaust. No increase in engine noise or abnormal noise newly detected. The valves have always been pretty noisy. No detectable piston slap.

WTH? At this rate of consumption shouldn't I see a huge cloud of smoke behind me or a huge puddle under the bike? Mileage is unchanged. Slight power loss. I think.

No new noises or for that matter any increase in valve noise.

I commute to work every day on it. 100 mile round trip. The only change I can think of is recently I've changed routes to work which now includes about 15 miles of WOT riding but that shouldn't have anything to do with oil consumption correct? Is seizure imminent (the bike not me)? How bad am I screwed running it on one quart of oil for 100 miles? Is it safe to ride? At $85 an hour for shop labor this is not getting torn down.

Any thoughts? Feel free to speculate, I'm baffled.

TIA for the help,
Retro

[Papa Lazarou]

Safe to ride but keep topping it up.

Does the exhaust look white-ie, is it burning oil? Could be the piston rings-old bike, low mileage can equal...worn engine

[Dan K]

I initially thought the oil could be backing into the airbox, soaking the filter, but not that much, and usually only when it's overfilled...

leaking oil into the radiator fluid?  Was going to say maybe leaking into radiator, but it's air cooled...good luck.

- Dan

[bomber]

many bikes ask that you check the oil level after the engine is warmed up and sits for X period of time to allow most of the lubricant to drain back into the sump.

other are very specific as to the position the bike should be in (held upright, on the side stand, balanced on top of the church steeple) while checking . . . .

first principles -- are you following the manufacture's method to a tee when checking?

[napper]

many bikes ask that you check the oil level after the engine is warmed up and sits for X period of time to allow most of the lubricant to drain back into the sump.

other are very specific as to the position the bike should be in (held upright, on the side stand, balanced on top of the church steeple) while checking . . . .

first principles -- are you following the manufacture's method to a tee when checking?

This was my exact thought.  

[Dan K]

If the problem is repeating (i.e., needed an additional quart more than once) then the problem is beyond letting the bike run and sit for ten minutes prior to checking again...)

- Dan

[bomber]

If the problem is repeating (i.e., needed an additional quart more than once) then the problem is beyond letting the bike run and sit for ten minutes prior to checking again...)

- Dan

Agreed, exccept the bike has now used 4.75 quarts of oil in a day, without leaving a puddle, covering itself with ribbons of shame, or doing a mosquito abatement distract impersonation.

This is likely more than the bike holds from new.

Something's wonky -- check it right, get a baseline is all I'm suggestion.

[Dan K]

Wonky is another good word.

Check the manual for the oil capacity at change of oil and filter to see if you are OK if the problem goes away....although 4.75 quarts seems high.

- Dan

[DogBoy]

recently I've changed routes to work which now includes about 15 miles of WOT riding but that shouldn't have anything to do with oil consumption correct?

15 miles of Wide Open Throttle? Is your commute on the Isle of Man?

If true, I could see that causing oil consumption on an old air/oil cooled bike.

[Max Wedge]

Checked on the side stand/center stand?

[Justin]

15 miles of Wide Open Throttle? Is your commute on the Isle of Man?

If true, I could see that causing oil consumption on an old air/oil cooled bike.

Yeah, really, what route exactly are you taking to work? Top speed on the Katana 1100 was about 140 Mph iirc - where are you pulling WOT on the way to work?  

Maybe you better not get that zx14 you wanted  

[retro]

Thank you all for the suggestions. Measured codl but I didn't look at the owner's manual to check the manufacturer's suggestion. Mosquito Abatement Program... Love it. I know, that's what I was expecting but as mentioned warm or cold that's a LOT of oil. I'll top it off tonight again and see what happens tomorrow.

Ya know that huge, long, lovely sweeper on 72 as you go by the wind farm and connect with 119? Last week not withstanding, it's usually not patrolled. Lurkers use your own judgement, there were 4 CHP on there this morning and a few sitting with radar earlier this week.. Between 72, Golden Highway and selected parts of Hover at 5:00am I have it rather open. 140 though never happen with me on it. 120 pound rider maybe. I need a good 1/2 mile to get up to the triple digits.

As for the oil burning at high speeds, I saw some posts on a GSX-R forum with some reports of a similar situation with the GSX-R1100 engine at interesting highway speeds. I think the Katana is the same engine block with a different cam and valve-train to get more mid-range torque. Same bottom end.

But that ZX...she calls my name....  

Thanks again,
Retro

[JSharp]

15 miles of WFO on an old air cooled Katana with 35K miles. But if you don't run it that hard it doesn't show much oil consumption.

My bet is that it's tired. Do a compression check and I'll bet it's low. Fortunately it probably won't grenade as long as you keep oil in it.

[Justin]

btw, did you pull your plugs and check to see if any were fouled with oil? Worth a shot to see if it's burning any, or if any is getting by the seals. Although at that consumption rate, you'd think you be seeing a lot of smoke.

[flips21]

Got a neighbor/co-worker/friend pulling a joke on you?

[jpaul]

How old was the oil when the problem first started? I'm currently riding a 79 GS750, and my previous bike was a 97 GS500. On both I noticed oil consumption increase noticeably after 2000 miles on a oil change. It's most noticeable when doing freeway riding. When the oil viscosity starts to break down oil can blow past the rings much more easily. I think this is more common with air-cooled or air/oil-cooled engines due to wider tolerances necessary.

[maddjack]

That much oil blowing ( 4.75qt??) by should show up as smoke or in the airbox, unless the box  has a drain that is letting it out before it pools deep  

What vis you running 10w40 or what?

[Hotbrakes]

Try a thicker viscosity, something like Rotella 15W-40 or 20W-50 and see if that brings "life" back to the oil rings.  It could be that you've still got good compression but the cross hatching on the cylinder walls and/or oil rings are worn so the oil is burning off efficiently.

You should also probably start mixing your gas to ensure adequate lubrication in the event that you neglect to maintain a sufficient oil level.  

[Andrew]

You should also probably start mixing your gas to ensure adequate lubrication in the event that you neglect to maintain a sufficient oil level.  

With a loss of 4.75qts He IS mixing the gas (sort of)  

Seriously have someone ride behind you when you nail the throttle (not tooooo close might be hard to clean up)  Look for Blue smoke

[Dan K]

So is it still running through oil?  Or has it had its fill?  Curious.

- Dan