Draining oil : hot, warm or cold

[Houtman_imp]

This has been discussed before I think but there was a good article in
Road Racing World (sept. 2019 ) Excellent magazine for people interested in racing.
I always drained my oil hot but will change to draining it cold.
Short of the story : Drain Hot 4.5 % oil left
Drain Warm 6.8 % oil left
Drain cold 0.3 % oil left

 

[GoldOxide_imp]

Use the gravity, Luke.

 

[the Ferret]

yea I brought up this subject back in 2015

http://cb1100forum.com/forum/showthread.php?tid=7592&highlight=oil+cold

btw i'm still draining my oil warm. Old habit die hard ...and I believe it's what the manufacturer (and nearly every one else in the world) recommends.

 

[peterbaron]

^^ +1, hot drain here as well, and let it drip for some time....

 

[Bazbro_imp]

Draining oil when cold is counter-intuitive ( hot oil is more viscous and 'runny' ) but I could understand that, when cold, the oil will cling better to itself, with gravity pulling it out better as a whole.

Also, workshops are under time pressures and the bulk of the oil will drain quicker presumably, than waiting... and waiting... and waiting for cold oil

 

[Houtman_imp]

The reason for draining oil cold is that all the oil is in the sump and all the contaminants will be in that oil. If still hot some of the "baddies" will still be in the engine. I always drained it hot ( including burns ! ) but from now I will drain it cold to see if more old oil will drain out.

Draining oil when cold is counter-intuitive ( hot oil is more viscous and 'runny' ) but I could understand that, when cold, the oil will cling better to itself, with gravity pulling it out better as a whole.

Also, workshops are under time pressures and the bulk of the oil will drain quicker presumably, than waiting... and waiting... and waiting for cold oil

Some of the better shops put the bike in a cooler for a while to get the oil cold.....

 

[Django]

I drain it hot and let it drip over night. Then it's cold in the morning.

 

[Cormanus]

Interesting numbers. Warm is the worst option?

 

[Houtman_imp]

Interesting numbers. Warm is the worst option?

Yes, warm was the worst , it was a well done test with great accuracy.

 

[Frulk_imp]

The difference between the hot and cold percentages is enough for me to consider doing it cold from now on.

 

[Gone in 60]

I drained what I thought was all of the oil out of my Bonneville before ordering valve shims and seals and heading off for a trip. It was warm when I let it drain, about 30 minutes after running, and it had stopped dripping after quite some time.

I hand-tightened the drain plug just so I wouldn't misplace it, figuring nothing more would come out, but put a towel under the bike in case it dripped. When I came back home, the towel was soaked, and there was a rivulet of oil that had extended down past the bike. Quite a bit more had come out. I think I'll pull the plug when it's warm, but let it drain overnight from now on.

 

[Houtman_imp]

I think that this is the reason engines get "over filled" , not all the old oil had drained out.

 

[GoldOxide_imp]

Give the engine a tinkle to tease the rest out.

- - -

Really, I just walk away from the drip and return at some random later time and refill. Never been a known issue.

Under normal use, a 100 mL of old oil will not do harm for an engine like this - it is not surgical equipment or anything of the like.

 

[peterbaron]

^^ +1, exactly... a drop of oil or two, will always stay there, not elsewhere

 

[GoldOxide_imp]

^^ +1, exactly... a drop of oil or two, will always stay there, not elsewhere

:rofl:

I think I see an "echo" in your comment.

 

[Bazbro_imp]

You actually WANT a tiny drop of oil to remain within the engine, to aid lubrication immediately after an oil change, when the full amount of oil hasn't yet circulated.

 

[the Ferret]

lol motorcyclists have the ability to take something so simple and make it so complicated

 

[Gone in 60]

By the way, what kind of oil should I be using?

 

[Django]

What you concern yourself with, gets big.

 

[Houtman_imp]

By the way, what kind of oil should I be using?

Organic , gluten free oil .
I probably opened a can of worms ( I mean oil ) but it was a good article in a VERY good magazine .