Porch

Is a fluid extractor of any use for an oil change on the n52 engine since there's no dipstick/dipstick tube? I still haven't received the car yet from the shop, but the reason I ask is on my vw, if I only drain the oil out the bottom of the engine, it leaves about a pint of dirty oil in the oil filter housing, and if I only use the fluid extractor, it leaves about a pint of dirty oil in the oil pan. So I always do both, and sucking most of the oil out with the extractor before pulling the drain plug makes oil changes so much easier.

spectre6000

Seems like a way to make it harder on yourself if you ask me. Every engine leaves a little oil behind during an oil change. Just the nature of the beast. A Mazda 13B takes a total of 9 qts when new, but an oil change only gets 4-5.

Porch

it makes it easier in the vw because you can get most of the oil out with the extractor through the dipstick tube and oil filter housing, so when you pull the plug, there's not that much oil left to drain. I'm trying to actually change the oil when I do an oil change, not just dilute the dirty oil, if that makes any sense.

spectre6000

It's a law of diminishing returns sort of thing. You could do an oil flush instead of just a change. Drain what you can, fill it back up, run it for a few minutes, then repeat until you feel you've diluted the various contaminants to your desired level. If you keep up with changes on a reasonable time schedule (not necessarily what BMW suggests; I like to do it on the 5s), change filters, etc. with high quality stuff, you'll have all the good happy long chain hydrocarbons and additives your engine needs to live a long healthy life. Dirty oil left behind from a decent maintenance schedule isn't going to be what kills an N52 powered BMW. I'm super anal about a lot of things though, and I certainly won't judge you for getting every last drop. If you figure something out, report back. I may add it to my own routine... Especially on the 13B, because that's nearly half the oil that doesn't get changed!

Porch

So sans any further input, what I'll try is to loosen the oil filter, then pull the drain plug. When the oil stops flowing, I'll see if I can suck any more oil out of the oil filter housing, and report back. Like I say, in my car, it yields about a pint, and since extractors are easy and mess free, I'm gonna get that pint.

Porch

So this is the oil that was left in the oil filter housing after pulling the oil drain plug and letting all the oil drain out. Turned out to be just less than a pint. Since I own a fluid extractor, there's no way I'm leaving that much dirty oil in the engine when I do an oil change. I also poured some fresh oil through the engine while the plug was pulled.