[Watsey]

Originally Posted by TurboWeasel

Thanks for that

Do you get much metallic dust on yours? I had a similar magnetic plug on my old Golf and that never had any metallic dust on it at all between changes.

Yes, there’s been a build-up of dust on the magnet for the past two oil changes.

I’ve used magnetic sump plugs on other privately owned cars and they’ve also had light build-up.

It doesn’t concern me, and I appreciate that the oil filter is there to do its job (including capturing the non-ferrous fines which the magnetic plug obviously won’t), but taking some/all of it out of the oil can only be a good thing.

[Allworth]

Originally Posted by TurboWeasel

Yup, but if you're still seeing metallic dust past 60K miles, something isn't right because the only ferrous dust will be coming from piston rings/cylinder walls and chains/sprockets. Roller cam followers produce zero dust, unless knackered, and bearings are non ferrous. Obviously I don't mean handfuls of the stuff, for clarity!

Let's be clear with arguments: Although most combustion engines, after leaving a factory, will produce lots of dust during the first thousand miles, it is still a good practice to flush out oil every once in a while in older engines as will always produce some. Aluminum dust is less dense than non-ferrous metal, thus less dangerous, but is still heavier than oil and will settle at the bottom due to gravity.
For some reasons this discussion reminded me of a 'good housekeeping institute' where bunch of people decide what's bad and what's good.
I personally prefer flush for a piece of mind.

[Watsey]

Originally Posted by Allworth

I personally prefer flush for a piece of mind.

Same here. I use oil flush (and gravity drain the oil via the sump plug), every oil change, as well.

Get as much sludge, varnish, carbon (piston rings), dust, etc, out of the system as possible.

[peetee]

I tried flush for the first time. Can't say I noticed any difference ...

It's 10th oil change (first time with flush), 85k miles

[danb1979]

Originally Posted by peetee

I tried flush for the first time. Can't say I noticed any difference ...

It's 10th oil change (first time with flush), 85k miles

I've used engine flushes a few times; never noticed any difference

Keeping the oil fresh with a decent filter, for me, is a better option...

Engine flushes for a 'new to you' car maybe; so you start afresh if that makes sense?

[Eddamoo]

Yeah every time I've bought a car, its always had a few 'long life' services before my ownership, so typically do a flush beforehand. Flushes are typically 90%+ paraffin/kerosine so i just use some diesel! Theres a few YouTube videos proving its got plenty of lubricity to work short term.

1. Drain Oil
2. Refill with some 5w30 LL04 mixed with 1L of Diesel
3. Run car for 15-20 mins at idle until warm (leave heater off)
4. Drain & replace Oil Filter - clean filter housing well
5. Refill with fresh oil

[TurboWeasel]

Originally Posted by Allworth

Let's be clear with arguments: Although most combustion engines, after leaving a factory, will produce lots of dust during the first thousand miles, it is still a good practice to flush out oil every once in a while in older engines as will always produce some. Aluminum dust is less dense than non-ferrous metal, thus less dangerous, but is still heavier than oil and will settle at the bottom due to gravity.
For some reasons this discussion reminded me of a 'good housekeeping institute' where bunch of people decide what's bad and what's good.
I personally prefer flush for a piece of mind.

Exactly, everyone has their preferred methods.

I had already looked at pictures of the inside of the N57 sump before getting the oil sucker as some sump designs don't work well with that method (mainly transverse FWD), but in the N57's case, both drain methods are effective.

See for yourself. https://www.ebay.co.uk/itm/275387183875

Look where the dipstick hole points the suction tube.....right into that pocket next to the drain plug, which is actually deeper than the drain plug because of it's threaded ledge.

You can also clearly see neither method gets all the crud out of the webbing and corners.

[Allworth]

Originally Posted by TurboWeasel

Exactly, everyone has their preferred methods.

I had already looked at pictures of the inside of the N57 sump before getting the oil sucker as some sump designs don't work well with that method (mainly transverse FWD), but in the N57's case, both drain methods are effective.

See for yourself. https://www.ebay.co.uk/itm/275387183875

Look where the dipstick hole points the suction tube.....right into that pocket next to the drain plug, which is actually deeper than the drain plug because of it's threaded ledge.

You can also clearly see neither method gets all the crud out of the webbing and corners.

Good, first time seeing any sump so detailed.
How quick is your pump? (rhetorical)
I could argue flow speed matters for flushing particles out.
I am not too sure if some heavier particles will get picked up by a pump due to gravity.

[TurboWeasel]

Originally Posted by Allworth

Good, first time seeing any sump so detailed.
How quick is your pump? (rhetorical)
I could argue flow speed matters for flushing particles out.
I am not too sure if some heavier particles will get picked up by a pump due to gravity.

I normally get it going, leave it and go and make a coffee or something, but I want to say about 8 minutes or something to empty the sump. I haven't really timed it.

Agreed. The fast flow out of the drain hole drags crumbs out with it. I do also use the sump bolt method, but I save that for when I jack the car up, such as swapping the winter wheels to summers etc. I just do the sucking method as a quick interim clear outs as it's more the soot saturation that bothers me more than anything else.

The only issue with jacking up just the front is oil moves into a corner that won't drain out because of the angle, so ideally a ramp is best for that method.

[Allworth]

Originally Posted by TurboWeasel

I normally get it going, leave it and go and make a coffee or something, but I want to say about 8 minutes or something to empty the sump. I haven't really timed it.

Agreed. The fast flow out of the drain hole drags crumbs out with it. I do also use the sump bolt method, but I save that for when I jack the car up, such as swapping the winter wheels to summers etc. I just do the sucking method as a quick interim clear outs as it's more the soot saturation that bothers me more than anything else.

The only issue with jacking up just the front is oil moves into a corner that won't drain out because of the angle, so ideally a ramp is best for that method.

Jacking and putting car on stands actually aids to drain oil for a few vehicles I had.
While drinking a tea I picked up some pics from google for educational purpose of 5 bmw F30 sumps; see how drain plug is conveniently located near the edge of a sump on 4 sumps not counting B58 and N57 as in your case. So if car is to tilt backwards it should only help for draining out oil.
By looking closer at a threaded drain hole can be seen it is not enclosed and has a cut out that brings it to a level of a bottom.

Your point about soot is spot on as its really harmful to an engine due to its abrasive properties and clogging.

[Allworth]

Originally Posted by peetee

I tried flush for the first time. Can't say I noticed any difference ...

It's 10th oil change (first time with flush), 85k miles

You can notice the difference by checking a bank account...
Someone said 3rd party additives are similar to non prescribed drugs

[Burnout]

Regarding normal amounts of iron in oil, it’s worth nothing that Blackstone universal data for all the N55 samples they have received has an average of 24 Parts per Million (PPM) of Iron.

I’ve seen 4-9 PPM depending on interval (with the exception of my first oil change after purchase which was 19 PPM), and those have been with a magnetic drain plug that typically has a small amount of metallic sludge stuck to it

[Allworth]

Originally Posted by Burnout

Regarding normal amounts of iron in oil, it’s worth nothing that Blackstone universal data for all the N55 samples they have received has an average of 24 Parts per Million (PPM) of Iron.

I’ve seen 4-9 PPM depending on interval (with the exception of my first oil change after purchase which was 19 PPM), and those have been with a magnetic drain plug that typically has a small amount of metallic sludge stuck to it

This looks like multivitamin nutrition facts table, very similar elements.
Phosphorus, Calcium, Molybdenum, Boron, Silicon - these elements only present in a synthetic oil and are higher than a reference value, which leaves me wonder which oil has been used.
Your observation with iron and magnetic plug only confirms that its working good;
there must be a reason why most car manufacturers tend to avoid use of a magnetic plug.

[Burnout]

Without hijacking this into yet another oil analysis thread, yep I was told the previous oil change before I bought it was done with Liquimoly, I’ve used the SpecialTec 5W-30 religiously and get consistent values for those first 4 elements (along with Zinc as well).

Silicone - Blackstone have been kind enough to flag my values are greater than typical even for this oil so I’ve been looking for air intake leaks.

As for the potential of there being OEM mag plugs, contrast that potential investment with how many parts are made of plastic that really should be metal that were already aware of.

Also a mag plug is an investment in longevity, ie keeping that extra material (however fine) out of the oil flow to hopefully keep bearing races less scored over time. It’s not essential to enable the car get through the warranty phase, so why would a manufacturer invest in it?

[TurboWeasel]

Originally Posted by Allworth

This looks like multivitamin nutrition facts table, very similar elements.
Phosphorus, Calcium, Molybdenum, Boron, Silicon - these elements only present in a synthetic oil and are higher than a reference value, which leaves me wonder which oil has been used.
Your observation with iron and magnetic plug only confirms that its working good;
there must be a reason why most car manufacturers tend to avoid use of a magnetic plug.

For the same reason they engineer temperature gauges to always sit in the middle. Average consumers are happiest with the middle and probably couldn't deal with the anxiety of swarf in their oil. Most gearboxes have magnets in them, but as they're sealed for life, average punters will never see that swarf.....which is much greater in volume than engine swarf.