To change oil with a warm or cold engine?

BrokenArrows

My old bike has been sitting idle for about 7 weeks and I want to sell it. The oil is practically black and in dire need of a change.

Everyone says to change warm but my theory is that because the bike has been idle all the crap in the oil will be at the bottom of the engine and I don't want to run this cap through the engine again.

Thoughts?

Hotblack Desiato

7 weeks is nothing. How long has the oil been in there? how many miles/km did it do since last changed? Is it cheap crappy oil or expensive synth oil?

To drain it properly it needs to be hot, oil just doesn't flow as well when it's cold and the slower it flows out the fewer particles it'll carry out with it. The aim is to get rid of carbon particles, tiny metal fragments etc. as much as change the oil itself.

If it's really bad, you could drain what's there, fill with cheap oil, warm it up (or preferably ride it for a few hours) and then drain it again while hot to get everything out and fill it up with the good stuff. But if you're selling the bike, there's no point.

Wonda-Boy

Deffo turn the engine over and let it runs for a least 3-4 mins...dont rev the ass off it just let it run.

Depending on where the sump is underneath a neat little trick is to tip the bike over on the side stand a little and drain the last little bit.

Hotblack Desiato

Oil won't be up to temp after a few minutes idling, 15 mins would be more like it (or better still ride it until up to normal temp) and then turn it off and let the exhaust pipes cool down for 10 minutes while you get ready to do the oil change. That way the pipe won't do you as much damage if your hand touches off it but the oil will still be nice and hot

SaoriseBiker

Wonda-Boy wrote: »

Deffo turn the engine over and let it runs for a least 3-4 mins...dont rev the ass off it just let it run.

Depending on where the sump is underneath a neat little trick is to tip the bike over on the side stand a little and drain the last little bit.

Exactly, just run it a few minutes and it will be grand.

Wonda-Boy

In an ideal world a nice short spin would be perfect but a bit overkill for an oil change on a bike he getting rid off. :rolleyes:

BrokenArrows

I just left it running for a few minutes while I made a cup of coffee and got the rest of the stuff together.

Wonda-Boy

Sorted, grand job. Make sure you put the sump nut back on snug and replace the washer around the dip stick if you can.