Question / Short Story:
I just started my bike after 5 months of "cold storage" in the shed. It started right up and after idling a couple of minutes I got a low oil pressure warning lamp and shut the engine off. I checked the oil level in the sight glass. The level was OK, but the oil appeared whitish. Upon further checking it turned out to be air entrainment in the oil ( full of small, < 1 mm, air bubbles) which cleared up after 20 minutes or so. Has anyone else seen this on a "cold" engine?
Last fall, I changed oil using Motul 3000 10W-40 and rode about 10 mi to distribute the oil before storing in the shed.
I was initially concerned about a coolant leak into the oil. I started it up again and rode to my garage (about 100 yards) where I could work on it. I was afraid to run it too much. Same result - the sight glass showed white oil. Again it cleared up after 10 - 20 minutes.
I borrowed a coolant system pressure tester from Advance Auto (quite a professional kit by the way) and confirmed there was no coolant leak - whew
I started and ran the engine for about 30 sec and again confirmed white oil. I drained it immediately and all the oil was the same condition - whitish - that eventually cleared. After internet research, I learned that oil "foaming" is lots of bubbles that cling together on the surface of the oil. "Air entrainment" is lots of tiny bubbles (<1 mm) distributed throughout the oil. This is my symptom.
This is the first I have used Motul 3000 so I changed the oil using Rotella T 15W-40. Same result - air entrainment.
In the past I have never looked at the oil sight glass on a "cold" engine. Perhaps it has always been this way and will be OK after a ride. I did idle until the coolant was up to temp, but I knowthat the oil was still not up to temp. Despite my concerns, I plan to go for a short ride tomorrow and take another look at the oil.
Has anyone else observed this?
Note: The initial "low pressure warning lamp" was probably caused by a low idle because I took off the choke too soon.