Motor Temp for Oil Change

[VmaXXX]

For some reason I'm second-guessing my habit of warming the engine before draining the oil. Is it really that important?

 

[MileHayabusa]

Doesn't hurt...gets a good portion of the 'junk' that's in the oil into suspension, drains easier when warm...only downside is you now have oil in the valvetrain and might need to wait a little longer if you want a 'full' drain of the old oil.

 

[VmaXXX]

...only downside is you now have oil in the valvetrain and might need to wait a little longer if you want a 'full' drain of the old oil.

Just what I was thinking. Bike has been stationary for several days on a paddock stand and I envisioned the oil all "settled" in the bottom.

 

[MaxMidnight]

The oil will be more viscous i.e thinner and therefore will flow easier and will be more likely to pool in the sump. As the mass of the motor will stay hot for some time then any at the top will drain down quickly.

I have no idea what the volume drained hot v. cold would be and provided the oil has been regularly changed would not see any issues if drained cold.

However if the bike has been sitting around for some time then there is the possibility that some condensation may have formed. As the water may not come out with the oil then getting to operating temperature will vaporise it.

 

[Fire-medic]

I have on-hand a few oil changes' worth of filters and oil. On a day when I'm ready for the change, after I return to the house, I do it then, when it's fully-at normal operating temp, and has-been for awhile, so as ouchez and MaxMidnight observe, any water vapor is hopefully out.

 

[VmaXXX]

Thanks guys. I presumed it was about viscosity and never considered water presence. She usually sits between weekends and with my area's extreme temp fluctuations I would definitely expect some condensation.