Oil Level

I know that oil--all liquids in fact--expands when heated. So I check my oil level after 3-4 minutes of idle and top it off so that there is a slight bubble at the top. Then after a long ride I look at the window and there is no bubble at all. Just for the heck of it I insert a tube and syphon off 4 oz and still no bubble. Seems like a lot of expansion to me. I'll be interested to see what happens as the engine cools. Any comments?

 

You know one of the comments already . . . . Does your oil smell like gas?

 

You should be checking after 4-5 minutes with the engine off. The oil has to have time to drain back from the heads and other oil passages. Only top it off after the oil has had time to drain back to the sump.

 

Ive noticed the 'bubble' is really susceptible to ground that is not level even when bike on centerstand.

 

No gas in the oil. I guess my question involves the difference in the oil level of a cold engine and a hot engine. My engine is cold now and there is a slight bubble showing. After getting it hot and letting it sit for 4-5 minutes the oil level is higher since there is no bubble showing. Are we saying that the bubble should show when hot, and therefore show a lower level when cold?

 

I check when cool. if there's oil expansion, I assume that the engineers probably already accounted for that in determining the capacity.

 

What ^he^ said. If you're running the oil level so that it's just a slim bubble (bottom of the miniscus touching the top line in the case) then it will look overfull when hot (but isn't).

 

Sounds good to me. That's what I've been doing but just wondered what's the purpose of letting it idle a few minutes. I assumed it was to heat the oil some.

 

I do that when it's time to CHANGE the oil.....makes it run out a whole lot easier.......

 

And running after the change makes sure that the oil filter gets filled, and lets you check for any potential leaks.

 

When it is hot I don't see the bubble so cant tell if it 3 ounces or a quart too full. Once it cools, the bubble reappears. Why didn't they make the full capacity line in the middle of the glass?

 

Because the middle of the glass would need to be higher?

 

my 550 has 2 lines maxium and minimum and still enough left over for a bubble

 

You guys really like to over-think things, don't you?

 

i cant help myself , I keep a pen and paper on my night stand in the morning i find I have written many a note to myself

 

My oil level sits exactly between the min and max lines. I don't see much variation between hot and cold.

Would it be better to have the oil sitting closer to the max?

 

'In-spec' is 'in-spec'

 

it is like the dip stick on a car max min level. the air pocket above the oil in the sight glass is so you can tell if your fuel leaked into the oil or you over filled it.

I drained a gallon of oil fuel out of my first XJ when I brought it home, you can put a lot of extra in there if you do not have the air bubble as a check.
add a few more ounces to fill to the line and its still in spec.