Oil changes: hot or cold?

[Mom]

Hot or cold?

Right you bunch of smart, educated and intellegent bikers answer me this. Was having a bit of a discussion at work today about magnets on sump plug bolts and other places around engines. Good idea, no doubt about it. Collects up all those pesky tiny slivers of worn metal inside your engine. The big debate came about when we started talking about warming the engine oil prior to draining it.

I say warm it, makes it less viscous (thinner) and easier to drain. Apparently if you do that all the metal bits are redistributed around the engine and stick there. I say the magnet deals with that.

A quick hands up at work gave 50/50 on warm up first, others reckoned drain the oil cold.

So, what is the right answer?

[Owl]

Hot I reckon:yes:

[merv]

Yep hot, that's what your manual always says. Then leave it to drain a while.

[quickbuck]

Hot....
No question.

Just don't burn your hands on the headers trying to get your filter off!

As for the "Metal getting disturbed inside your engine" I call BS!
The filter will catch that.

If you have metal running around in there it will get in your bearings and wreck them quick smart!
It pretty much goes straight to the filter as soon as it gets created.

Also, the magnets will pick up the bits that contain iron, but there is much metal in your engine that is not ferrus...

If you want to give yourself a heart attach, cut open your filter one day and see how much it catches....

[Bikemad]

Yep............as above..........

[howdamnhard]

Do it when it's hot. It would have to be flowing really fast to remove the iron bits from a magnetic sump plug. The filter does most of the removal,the magnetic plug just lets you know something is on the way out.

[MaxB]

Hot always, for reasons already mentioned.

Be an interesting time at work tomorrow esp. if you're a 'majority of 1'.

[CookMySock]

There is no point to a hot drain. Think about it for a while.. All it does is help you get the very last bit of the oil out of the bottom of the sump, and what's the point of doing that when you just undid all the goodness of an overnight drain of the top-end of the engine - by starting it!

Don't start it and push the old oil all through the engine. Leave the bike overnight to completely drip down internally, and then drain it cold and let it drip into the tray for an hour. Tilt the bike left and right if you are able, to get the last bit out of the sump. Wipe the filter housing out with a lint free shop towel. After this, you will have the minimum amount of old engine oil remaining.

I think you can safely forget about this visualisation of metal shards all though the bike. If there is any, the strainer, the filter, the plug magnet, and the stator magnets will take care of that.

Anyway, large levels of pedanticism is not necessary changing engine oil. It is the pink blankie under its' bike cover approach, and serves only to make the rider feel better. But hey if it feels good - do it!

Steve

[Mom]

Hot always, for reasons already mentioned.

Be an interesting time at work tomorrow esp. if you're a 'majority of 1'.

No there were a couple of us "hotties" but, there were also some "male know it all, get back in the kitchen" types who were absloutely right doing it cold.

[TimeOut]

Defiantly hot, it gets all the other crud suspended in the oil. But I try to let it drain overnight to get it all the oil out (as Steve said)

If you change it cold some of the contaminates will settle to the bottom of the sump and stay there.

[Owl]

Right you bunch of smart, educated and intellegent bikers

Mom, are you sure KB was the right place for this thread?:innocent:

[CookMySock]

If you change it cold some of the contaminates will settle to the bottom of the sump and stay there.It is tempting to visualise this happening, but I am not persuaded. I would be interested in theories or practice on what solids may have bypassed the filtration methods mentioned, or what liquids there may be that have separated from the engine oil.

Steve

[scumdog]

Defiantly hot, it gets all the other crud suspended in the oil. But I try to let it drain overnight to get it all the oil out (as Steve said)

If you change it cold some of the contaminates will settle to the bottom of the sump and stay there.

Hot or cold (mostly cold) and I leave it overnight as above.

[T.W.R]

I would be interested in theories or practice on what solids may have bypassed the filtration methods mentioned, or what liquids there may be that have separated from the engine oil.

Steve

You'd be surprised what settles in the sump of a motor, especially in older engines........swarf, sludge, gasket particles, sealant etc
Motorcyle engine oil pumps don't operate at especially high pressures and the majority of internal oil galleries aren't large so bigger particles just end up collecting in the bottom end

Even with draining oil hot and leaving to drain for a period of time it's always worthwhile flushing with a small amount of fresh oil too before refilling

[red mermaid]

Warm, or hot, and I always change the filter as well as its only $20.

[YellowDog]

There is no point to a hot drain. Think about it for a while.. All it does is help you get the very last bit of the oil out of the bottom of the sump, and what's the point of doing that when you just undid all the goodness of an overnight drain of the top-end of the engine - by starting it!

Don't start it and push the old oil all through the engine. Leave the bike overnight to completely drip down internally, and then drain it cold and let it drip into the tray for an hour. Tilt the bike left and right if you are able, to get the last bit out of the sump. Wipe the filter housing out with a lint free shop towel. After this, you will have the minimum amount of old engine oil remaining.

I think you can safely forget about this visualisation of metal shards all though the bike. If there is any, the strainer, the filter, the plug magnet, and the stator magnets will take care of that.

Anyway, large levels of pedanticism is not necessary changing engine oil. It is the pink blankie under its' bike cover approach, and serves only to make the rider feel better. But hey if it feels good - do it!

Steve

Good contrary post Steve!

I always warm it up because it does tend to flow better when warm. It also says to do so in the manual.

I also leave it over night and tilt left and right to get as much out as possible and also pour (waste) around 300ml of new oil back in just to get the grubby bits that don't quite make it.

I realise that this is a bit anal but that's how I do it.

I had a magnetic plug on my old bike and never found anything metalic attached to it during an oil change.

[bogan]

Well if you are changing rad fluid you can have the best of both worls, just leave sitting overnight, then flush hot (boiling to be best) through radiator for about an hour while draining the oil, will heat up and come out real good, and there will be bugger all oil sitting anywhere else :D

[scumdog]

Warm, or hot, and I always change the filter as well as its only $20.

Yep, change the oil and not the filter?

Ya might as well wipe only half your arse....

[Edbear]

Hot or cold?

Right you bunch of smart, educated and intellegent bikers answer me this. Was having a bit of a discussion at work today about magnets on sump plug bolts and other places around engines. Good idea, no doubt about it. Collects up all those pesky tiny slivers of worn metal inside your engine. The big debate came about when we started talking about warming the engine oil prior to draining it.

I say warm it, makes it less viscous (thinner) and easier to drain. Apparently if you do that all the metal bits are redistributed around the engine and stick there. I say the magnet deals with that.

A quick hands up at work gave 50/50 on warm up first, others reckoned drain the oil cold.

So, what is the right answer?

I can't really say more than has been said... :innocent:

[Metastable]

Either is good for me. I just depends when I want to do it and what's going on. The key thing is just changing the oil frequently enough. There is such a small difference between warm and cold that it really doesn't matter much.

The ONLY consideration when it is cold is that most of the oil is at the bottom as opposed to it being a bit more spread out when checking the level 4 minutes after running the bike. So if you do it cold you might need a bit more oil to top up.

IMO, it doesn't matter much.

[AllanB]

An interesting post by Steve - you been cut and pasting of the net again mate? he he he just yanking it.

I've always done mine hot-ish - basically after a ride, park and let it cool for a half hour or so to avoid burning my hands. I always allow it to drain until there are only random drips (like KB).

I've cut open all the oil filters off my Hornet from new and I've not found any visible crap in them. But it is a Honda.

Personally I think the old tale of a new engine having lots of machining crap in it is bollocks. It may have been true 40 years ago.

[Motu]

Draining is mainly a time thing,specially if you are paying for it - hot oil drains quicker.If you have the time,a cold drain gets more oil out,and the stuff that settles to the bottom (it does) goes out first.Some diesels (mainly American) use an oil that doesn't suspend to soot to be then filtered out,the soot settles to the bottom to be taken out with the drain.

[CookMySock]

Either is good for me. [...] IMO, it doesn't matter much.I think that is a fair summation of it.

There are only a couple of don'ts, and they are more about not overtightning little wee bolts, or making sure there not two gaskets fitted instead of one and a few little who-the-fuck-would-have-thoughta-that things.

As long as you actually change your oil on time, and do the filter as well, there is little to go wrong. Just as always - be vigilant for the first 10-15 mins running.

Steve