Letting Oil Drain Overnight

[ZZman]

Ain't got time for that. When it starts dripping the bolt goes back in.

 

[garageman402]

Ever stick a straw into a glass of water and then put your thumb over the open end and lift the straw out of the water? There is water retained in the straw until you remove your thumb. When an oil filter is removed, it can open up that part of the oiling system to the atmosphere and essentially release trapped oil in the oiling system, and if that trapped oil then drains into the pan instead of out the filter mount (depending on the oiling system design), then it will drain out the oil pan drain plug.

Thank you for that. I needed backup, Lol. I was getting answers as to the oil draining back out through the filter mount as opposed to draining out through the pan. In fact someone had done thousands of oil changes & "never" had that happen. Probably put the plug in before changing the filter.........

Oil pumps are not submerged in oil ... but the pick-up tube that feeds the pump is. When the sump is drained, the oil in the pick-up tube up to the pump itself will most likely also drain out. In most cases, I don't think the oil that is inside the pump drains out, because the fit of the rotor tips to the pump housing is usually pretty tight and will retain the oil that's captured inside the pump. It's possible if a pump was worn or the clearances were loose that it could drain out and lose its prime. In all the vehicles I've change oil on, I've never seen any indication that the pump lost its prime, and oil pressure builds up pretty quickly for a sump dump.

So the oil pump must be capable of pumping air in order to get the oil up through the pickup tube. When a new oil pump is installed, is it generally primed first? I would assume it has assembly lube in it. Since it is a positive displacement design, no oil can drain back out from the pressure side even when the filter is removed allowing air in the figurative "straw". Unless, as you mentioned, the pump is worn so much that the column of oil can leak down through it. Even if that was the case, it would still pump air to bring the new oil up into it I would think.

 

[nomas]

Ain't got time for that. When it starts dripping the bolt goes back in.

Pretty much . When it gets to one drip per 3-4 seconds it's a done deal . Overnight ......geezz.

 

[hrv]

Lets go for 12

 

[ATex7239]

 

[ATex7239]

A picture of that last bit of old oil you left in the engine watching you reinstall the drain plug…

 

[TiGeo]

A picture of that last bit of old oil you left in the engine watching you reinstall the drain plug…

Brilliant.

 

[DavidJones]

My F150 has the 2.7 Ecoboost engine. Ford recommends waiting 15 minutes after shutdown before you check the oil, so the auto SS reservoir has time to bleed down. Based on that, I'll take the plug out and let it sit an hour plus before I consider the oil drained.

 

[Revving2Redline]

If you aren't draining/filling 6x are you even changing your oil?

wow, that made me the extreme of getting the job done it sure waste a lot of material. as long as people are getting a good solid drain I don't think there's much more that can be done without pulling the pan or doing an engine flush. we see that happen too often now with people who own CVT transmissions. if they would have changed the fluid like they were supposed to at a reasonable interval they wouldn't be trying to do all these drain and fills back to back. I feel that doing a drain and doing your feel and driving it no less than a thousand miles or so gives it a real true chance to circulate and get mixed in. whether or not the damage is already been done by the old fluid it was in there for so long.

 

[CleanSump]

Dismantle and clean all internal parts. Reassemble using quality assembly lube as listed in the EOM manual.
Fill with the oil de jour (Mobil 1 or HPL, Rotella if you are a motorcycling cheapskate).
Done!
So simple.