Drain or Pump out the old oil?

[ericm979]

I think the amount of solids that are removed with draining vs suction are going to depend on individual engine details like the exact shape of the oil pan at the drain plug (i.e. some plugs are on the side of the pan or the plug hole has a raised lip on the inside) and for suction, how well the dipstick tube lines up with the lowest point of the pan.

Some of my vehicles have the oil filter on the top of the engine which is super convenient. I'm still draining from the drain plug mostly due to inherent conservatism around mechanical objects and not wanting to have to find a place to store yet another tool.

 

[5030]

Would never work on either of my Kubota's, both have split oil pans. The front drive shaft goes down the middle

 

[RalphVa]

I've never really enjoyed crawling under a car or tractor to gravity drain the oil. Even if it goes right it is still a bit of a mess.

So recently I've been wondering....Why not pump the old oil out the filler hole instead? Clean and simple - and easy to put the exact same amount back in.

I wonder how many mechanics do it this easier way, and what you've learned along the way?
rScotty

Think I heard the local MB dealer sucks all the oil out.

I started extracting mine, even on the tractor, a few years back. First time I did it, I extracted and then removed drain plug. NOTHING came out of the tractor's crankcase.

I'm done doing oil changes on the 2 Mazdas and the Toyota. Japanese engineers (except Subaru) put the oil filter underneath. Gonna get it done after this on them.

I use the dipstick hole. I just place the dipstick by the extractor suction line and mark with my finger the length of the dipstick and stick the extractor line in that much, working it back and forth just a tad in case too far or not enough.

Don't think it'll work through the oil filter hole, plus you won't know how far.

 

[Oaktree]

I think the amount of solids that are removed with draining vs suction are going to depend on individual engine details like the exact shape of the oil pan at the drain plug (i.e. some plugs are on the side of the pan or the plug hole has a raised lip on the inside) and for suction, how well the dipstick tube lines up with the lowest point of the pan.

Agreed. On most, if not all vehicles I've ever owned the oil fill hole doesn't pour directly into the pan, but is generally on the top of the engine where the oil drains down into the pan eventually. Likewise most dipstick tubes are what, maybe 3/8" diameter? Not a very efficient way to get the old oil out, and still no guarantee you're getting all the sludge.
Yeah, some vehicles (4WD trucks/SUVs in particular) have skid plates that are in the way of the drain plug, but to me still seems the easiest way to drain.

My Kioti's oil pan is like 5030's Kubota...split with front driveshaft running down the middle. Easy enough to get at the drain plugs on it.

 

[Rockbadchild]

Agreed. On most, if not all vehicles I've ever owned the oil fill hole doesn't pour directly into the pan, but is generally on the top of the engine where the oil drains down into the pan eventually. Likewise most dipstick tubes are what, maybe 3/8" diameter? Not a very efficient way to get the old oil out, and still no guarantee you're getting all the sludge.
Yeah, some vehicles (4WD trucks/SUVs in particular) have skid plates that are in the way of the drain plug, but to me still seems the easiest way to drain.

My Kioti's oil pan is like 5030's Kubota...split with front driveshaft running down the middle. Easy enough to get at the drain plugs on it.

When I built a skid plate or if there is one already in place I always poke as hole for the oil drain plug.

 

[LD1]

Oil fill wont work on most engines. Would have to use the small dipstick hole. Cant help but think that would be a slow process.

Im not gonna re-invent the wheel. Drain pans and drain plug for me.

 

[Williy]

These quick lubes suck the o;il out
NEVER go there as if any sediments
in bottom of pan they are not removed
so I only drain

willy

 

[Robin Veerman]

Some of the European diesel engines - think Mercedes Sprinter - have a ridiculous long interval between oil changes
I find doing oil changes when it’s convenient makes the job more palatable. So a long drain interval is an option if using certain Amsoil synthetics. Their Signature Series, whether Gas or Diesel engine oil, can easily extend the oil change interval out to 2or3 times. It’s what I’ve done for over 30 years. I don’t stretch every oil change interval to the max. But it just gives me the peace-of-mind that I can wait until it’s convenient for me, instead of the urgency of an oil change simply due to a mileage/hour number...

 

[jjeff]

A few minor thoughts from experience, some oil drain plugs have a magnet on the bolt how are you supposed to clean it off? I heard somewhere that some quick change oil places suck it out cause they don't want there minimum wage "service techs" stripping out the drain plugs. Finally when I used to service diesel and gas inboards and I/Os on boats I used to really dislike pumping oil out of dipstick holes it took forever and I was always had to reposition the suction tube in an attempt to get it all out. Notice newer boats come with a drain hose that pulls out the bilge drain plug hole and dust on unused oil sucker. Sucking oil sucks, imo/experience.

 

[5030]

These quick lubes suck the o;il out
NEVER go there as if any sediments
in bottom of pan they are not removed
so I only drain

willy

I would NEVER use a 10 minute oil change place for a number of reasons, sucking the oil out not with standing...

One, you never know what oil they are putting back in, they may tell you it's XYZ premium oil but you don't know because it's coming out of a drum and being pumped into your filler, what is really being installed, you have no idea other than what they tell you.

Two, do they use a quality oil filter or some cheap generic one or maybe a cheapo Fram? You don't know and they are always trying to upsell you on other stuff like air filters or a tranny flush (which you really should never do, especially on a higher mileage vehicle. I have no issue with changing the trans filter bit in reality, you should put the fluid back in (if it's not burnt) and not add new fluid. Modern tranny's use a synthetic fluid, designed to last the life of the vehicle, don't be changing it unless you have an Allison but them most people that have a pickup truck with an Allison don't use a 10 minute oil change emporium anyway.

Finally, most of those places use labor that aren't really qualified in the first place, aka: high school kids, part time help.

I'll always do my own routine services.