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Sorry to create another thread about oil, but I have a serious question: Is there a check valve somewhere in the system that prevents the oil from draining out of the oil cooler and into the engine when the engine is turned off? For the second time now I have experienced a disturbing condition concerning the proper oil level in my bike. I created a post on this topic a few years back, but I never really got an answer that helped to resolve this issue. I checked the oil level in my bike prior to a ride last Sunday, and to my complete surprise the level was at the lower line. My bike had sat for two weeks without being ridden, so I believe that is plenty of time for the oil to flow into the crankcase to perform an inspection, and yes, the bike was on completely level ground. Just to be sure, I performed the oil inspection procedure defined in the owner's manual by starting the bike up, allowing it to run for about two minutes, shutting it off, waiting for the oil to drain back into the crankcase for a few minutes, then reexamining the level in the sightglass; I performed this twice. Each time the level actually was slightly lower than the lower line on the sightglass (if I waited longer it probably would have risen ever so slightly). I proceeded to very, very carefully add oil, a small amount at a time, starting the engine and performing the check oil procedure each time I added a small amount. After repeating this procedure three times I had the oil level exactly even to the top line on the sightglass (I added approximately 12 fl oz). I figured everything was Ok, and my wife and I went for a ride to visit Laguna Beach, via Ortega Highway, about a 140 mile round trip. When I got home I rechecked the oil level, and at this time it was so high the sightglass was completely filled. I performed the inspection with the bike on level ground, located in the exact same position it was in when I topped the level off prior to our ride. Does anybody have an explanation for why more oil drains into the crankcase at times, causing inconsistent oil level readings?
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Running the engine for a couple of minutes only warms the oil a little. After a long run it is well up to temperature and hot and has possibly expanded up to 10% in volume to make the difference.
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Are you using 10W30 conventional oil?
Some owners use a heavier grade like 10W40 and some even heavier in the boilerplate regions of the southwest. 10W40 may not expand as easily and may be even more stable if it is synthetic based.
So to properly Christian this oil thread, 10W40 synthetic may provide a more consistent physical behaviour during hot summer runs.
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(08-23-2022, 03:34 PM)Cormanus_imp Wrote: Christen, Au₂O₃?
... thanks Cormanus.
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To answer one thing Dave asked, there is no oil check valve. There is an oil flow diagram in the service manual that shows no valve.
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Thank you for your replies. I am using the Honda brand 10w30 full synthetic. That's a good thought about the volume of the oil expanding when it gets hot, but I rechecked it the next day with the engine cool and the level is the same - the sightglass is completely full. What are your thoughts concerning something preventing the oil from flowing back into the crankcase at certain times to allow an accurate measurement? What stops the oil in the oil cooler from completely draining into the crankcase whenever the engine is turned off, or does it?
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My thoughts are checking oil in this bike, and my ST1300, is kind of a big pain to get right. But I don't obsess over it though.
As far as oil cooler draining I don't know. The connections are at the top so unless it siphons out I guess it still holds oil. I have never had my cooler off so IDK. Hopefully someone else can speak to this.
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In my history of Honda ownership with oil coolers, I've never was concerned about the radiator caching or not caching the oil.
Engine block oil level is a non-precise issue.
The mechanical designers build in enough "safety" margin to allow for underage and overage fill levels. The "dipstick" and similar level-viewing tools are barely civilian-grade and hope to bring owners into a psychosis focus to help ensure the built-in margins are not tested.
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(08-24-2022, 01:29 AM)Lord Popgun_imp Wrote: My thoughts are checking oil in this bike, and my ST1300, is kind of a big pain to get right. But I don't obsess over it though.
As far as oil cooler draining I don't know. The connections are at the top so unless it siphons out I guess it still holds oil. I have never had my cooler off so IDK. Hopefully someone else can speak to this.
My thoughts exactly too ..change the oil and filter, put in 4 qts of oil, don't worry about it again* until you change it in 4,000 miles. Has worked for me for 69,000 miles so far.
* unless you are blowing white smoke or find drips/puddles of oil on the ground beneath the bike
