Sight Glass Oil Level- What is the Secret ???

Andrew Shadow

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2009 ST1300A9
When I bought my 2009 ST1300 in December 2012 the oil level was low in the window. I put some oil in to bring it to the top line. Then I ran the bike, let it sit and rechecked. It was now way overfilled. I drained a bit out and did the same. Then it was to low again. I added a bit and went through the process again. Now it was overfilled again. So I dumped the oil completely and changed the filter. Refilled it with 3.9 litres of oil and went through the whole viscious cycle again all over again. I thought I had mis-measured. Then I found on this site that these engines are often overfilled and that the sight glass oil level is always screwy. I read many posts about this and they usually end with a consensus to dump in a gallon of your favourite oil and go ride. I am not really concerned that I don't have enough oil in the oil pan as I know I put in the correct amount. For the life of me the level is never correct according to the sight glass.

Friday I changed the oil;
I ran the engine until fully warmed up- engine cooling fans cycled several times.
I removed the oil fill cap.
While on the center stand on a perfectly level surface I removed the oil filter and drained the oil while the engine and the oil was hot.
I let it drip overnight so the oil pan was completely empty.
I installed a new Honda OEM oil filter.
I measured out EXACTLY 4 litres of oil in to a container.
I filled the oil pan with exactly 4 litres of oil and ran the engine until the cooling fans had cycled a few times.
Shut the engine off and let it sit for about 30 minutes.
Oil level was just below the lower level line in the sight glass. I did not add any oil.
Sunday I went for a 90 mile ride.
When I got back I parked the bike on the center stand in the exact same spot on the perfectly level surface.
I let the bike sit overnight.
This morning I checked the oil level in the sight glass- you can see the result in the attached picture. It is not even close to the upper line.
I cannot possibly be more exacting in following the manual nor be more precise in the amont of oil I put in and yet the oil level in the sight glass is no where near accurate assuming the correect amount of oil will bring the level to the upper line in the sight glass.

I am not really concerned that I do not have enough oil in the engine because I know that I poured in exactly 4.0 litres. I am not concerned about riding the bike like this because I know I have enough oil. It just frustrates me because on every bike that I have ever owned with both sight glass oil level indication and with dipsticks (including 2 ST1100's) when I change the oil I always adjust the oil level to exactly the upper line in the sight glass or the top line on the dipstick when checked with the engine cold. This always takes the amount of oil specified in the manual or very close to it. I use this as my baseline reference point so that I can very easily and regularily perform a visual check to see if the engine is using any oil between oil changes. What frustrates me with this bike is no matter how precise I am with the oil change procedure and no matter how eaxacting I am with the amount of oil I put in I cannot do this same very quick and simple check because the oil level in the sight glass always seems to be all over the place.

What is the secret that I haven't figured out yet? Is the upper line in the sight glass not indicative of having the correct amount of oil in the engine?
 

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What is the secret that I haven't figured out yet?

The secret is NOT TO WORRY!

Depending on the filter ( oem or not ) you can use slightly diff amount of oil... the bottom line to the top is about 6 oz or so of oil.

I put in a 4 qts with a non oem filter and it gets me oil in the sight glass near the bottom line... I ONLY check it in the AM when cold and on the centerstand....
If I want to be anal, I can add another 1/4 to 1/3 qt to get it to the top line, but don't bother anymore.

BTW, thats a perfect pic... if it appears like that every am, don't worry.
 
What Tom said.

Honda gives you a spec for oil level, and as long as what's in the sight glass is within that spec, you have enough oil.

--Mark
 
The nice thing about the ST1300 is you change you oil and never have to add a drop for the 8,000 miles when Honda states to change it out in.
It's that easy.
Again, the fella I bought my bike from gave me a demo on how to change the oil, drain, new filter and 4 quarts of oil. His statement is true to this day. Again, if you want it perfect, add 4 to 6 ounces more in the morning while it is cold. I like to drive it for a day before any top-ups myself as things mysteriously change.
Sorry, I know some of this has already be mentioned, just want to give you my way of doing it.
 
While I was riding today I came up with another theory on this matter. On all my other bikes the specified amount of oil brought the oil level up to the top line of the sight glass or the top of the hash mark on the dipstick when checked on a cold engine. Maybe the design of this engine is such that topping off the cranckcase with oil to the top line when the engine is cold would result in an overfilled engine once the oil has expanded in a hot engine. Maybe the top line is where the oil level rises to in a hot engine which has the correct amount of oil in it. I have never checked it when hot. A theory to examine out of curiosity.
 
Does honda give direction on how to check it cold anywhere in the owners manual?

I only found this.
1. Park your motorcycle on its center stand on a firm, level surface.
2. Start the engine and let it idle for 3-5 minutes. Make sure the low oil
pressure indicator goes off. If the indicator remains on, stop the engine
immediately.
3. Stop the engine and wait 2-3 minutes.
4. Check that the oil level is between the upper and lower level marks in the
inspection window.
If the oil is at or near the upper level mark - you do not have to add oil.
If the oil is below or near the lower level mark remove the right over
head cover (page 90 ), the oil filler cap and add the recommended oil until
it reaches the upper level mark. (Do not overfill.)
5. Reinstall the oil filler cap, and right over head cover.
6. Check for oil leaks.
 
Even though I have a ST1100, it has a similar sight glass. After changine the oil and filter my level looks exactly the same. It is full. You are fine. Go ride!
 
Maybe the design of this engine is such that topping off the cranckcase with oil to the top line when the engine is cold would result in an overfilled engine once the oil has expanded in a hot engine. ... I have never checked it when hot.

Don't panic when you do, because there won't be anything in the sight glass. The oil pump will have moved a bunch of what was in the pan into the engine and oil filter. The five-minute wait before checking after you stop is to allow most of what was pumped away to run back into the pan.

Keeping the oil at or below the upper mark leaves enough room that the crankshaft won't dip in and whip it into a froth, and that's really the only reason there's an upper limit.

--Mark
 
When you pull the front of the engine off, you will find that the oil pan is actually segmented into (at least) two sections. The front section has a separate intake tube to keep the oil in there "fresh." I have always thought - albeit with no proof- that the reason the site glass was sometimes unreliable was because depending on a variety of factors various amounts of oil could get caught in the front portion of the oil pan.

As noted, I have no proof- but as this is somewhat related to oil, I felt free to post an opinion. :)

Like many others, I have developed a habit of just installing 4 quarts and calling it good. After a hard day, I will let the bike it on the centerstand just to make sure I can see some amount of oil in the glass.
 
I don't have the manual at hand but I believe it says 3.8 quarts. One gallon is close enough.

Please feel free to correct me if I am wrong.
3.8 quarts if only draining oil; 4.1 quarts when draining oil and changing filter. So one gallon IS close enough
 
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Specification is 3.9 litres or 4.1 US quarts including filter change. I put in 4.0 litres.

I always check the oil when the engine is cold. The procedure in the manual doesn't even make sense. Running the engine for 3 minutes at one temperature versus another will result in very different oil temperatures and therefore completely different oil level readings. The range between full hot and anything above cold is so wide any comparitive oil level reading taken at anything but cold would be so variable as to be of no value.

I am not concerned about the actual level of oil in the cranckcase. I was simply questioning that you don't get a reference point so a quick visual determination can be made if any oil is being consumed / lost. Same logic as tire pressure. i.e. If you don't know what your tire pressure was you don't know if you have lost any air pressure when you check it and therefore you don't know if you have a problem. If the oil level in the sight glass is not lined up with a reference line it can be compared to consistently you can't easily determine if you are loosing oil- and therefore have a problem. I just thought that a properly filled crackcase would bring the oil level to the upper mark. I guess not!
 
I just thought that a properly filled crackcase would bring the oil level to the upper mark. I guess not!
Yeah, I bet you didn't expect such a wide range of answers, opinions and observations- most from people who (probably like you) spent a lot of time laying on the ground trying to work it out. Seems like a simple issue--- yet.
 
I fully expected all the answers and opinions- just look how much space gets devoted to pie on this site!
I actually haven't spent much time at all lying on the floor investigating. I raised the question here so that I wouldn't have to. I have my own plan to soolve this.
 
I was simply questioning that you don't get a reference point so a quick visual determination can be made if any oil is being consumed / lost.

The lower line is the reference point. If the level falls below there during a by-the-book check, you're consuming oil.

Oh, and pie. :pie1:

--Mark
 
Blrfl;

The oil level reaching the lower level line tells you that you have already consumed / lost a substantial amount of oil. I want to know if there is a problem before then. To be more precise the reference point I am referring to would be one that aligns with the oil level when it is filled with exactly the correct amount of oil. You then have a starting point to reference from and can then tell if there is any oil lost. I assumed that the upper line would be such a reference but apparently it wasn't engineered that way. No problem- maybe I will add another reference line at the appropriate place.
 
I just put one gallon of oil in the ST when I change the oil and filter and then just ride it and don't worry about it. Keep it simple and don't worry about the up and down on the site glass.
 
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