How much oil is left in engine after draining it?

[Bob The Builder]

The subject pretty much says it all. I would think that if you drive a vehicle and get the oil nice and hot, then immediately drain it and remove the filter, that most of the oil would end up in the collection container...except for maybe a film of oil on internal parts.

Is this true, or does an engine retain a significant amount of oil...I've heard as much as a half to 1 qt remains. (I have never actually measured the amount of oil coming out.)

In this case, wouldn't it make sense to run a cleaner just before draining?

 

[Quest]

yes, you are indeed correct that there may be approx. 1/2 ~1qt of oil left behind when you drain the oil out of your engine.

That being said, however, why on-earth would you consider running cleaner before draining?

Also: when you say "cleaner", do you mean stoddard solvent like those OTC "10-min laxatives" (aka "engine flush")?


Q.

 

[simple_gifts]

I would rather have 1/2 qt of 8K syn oil in the crankcase when refilling my engine that 1/2 qt of dirty solvent

I have done many 3-4K conventional OCI without even changing the filter and never had 1 concern....

 

[ewetho]

Yeah a dry engine requires anywhere from 0.5 - 1.5 qts more and diesels really need oil. Heck like a gallon stays in the engine when you do an oil change.

If you do a flush just change the oil twice when done. Change it and then run it for several minutes and do it again. Heck I got a 5 qt. jug with all the left overs from the last couple of years in it to do that with.

 

[Bob The Builder]

Well....yeah. By cleaner, I meant Amsoil Flush. I actually used that recently and I must say that there was a ton of crud that came out.

In went the SSO and what a difference! Incidentally, I passed smog afterwards.

 

[SubLGT]

In the Subaru 2.5L turbo motor, about 0.7 quart of old oil remains in the motor during a standard oil & filter change.

I see no significant value to doing a routine flush with "cleaner".

 

[Steve S]

No on the flush because that is what the oil change should do. You want to change the oil before the point that the oil is " bad".

 

[Roger]

According to my Civic's owners manual, engine capacity is 4.7 qts, but a refill with filter only takes 3.9 qts. I figure that leaves about .8 qts old oil in the engine with every change.

 

[Pablo]

Just allow it to drain really well. As excellent as Amsoil flush is, you don't need to run it every time. Simply no need. Some engines retain more oil than others.

But this is the reason I change my filter every oil change. No sense leaving used oil in the engine or filter.

 

[PW01]

judging from my dipstick, I'd say 1/2 quart is left in my truck.

 

[Audi Junkie]

More like 1-2 quarts if you look at shop manuals for specs after teardown.

 

[smokey1]

if yeh want to get little more of the old oil out of pan just pour about 6 ounces of the new oil into it and let it drain out oil pan along with the old .

 

[mechtech2]

The many oil passages, pump, and other crevices will have residual oil in them.
With a good drain, maybe 1/2 qt. can be left. On newer small engines, I doubt even that much with a good long drain.

 

[Doug Hillary]

Hi,
many engines retain a substantial amount of lubricant at an oil drain

V8 Porsche engines (928s) for example have anti-drain back check valves in each head and such things as oil coolers etc do add to the retained volume

As mentioned earlier, some heavy truck engines also retain a substantial amount of lubricant too

 

[Delphi]

So, is your almost general consensus that using the "flush engine" bottle is not good for the engine?

I was planning to use it when changing the oil next time, believing it will help to remove all the contaminants from the oil. My engine is using 3.6 liters (including new filter), but never used more than 3 liters. I have considered to use this Valvoline product Engine Flush

 

[ekpolk]

The last one that I actually looked up was the 3.0L 1MZ-FE V-6 installed in the Camry I had a few years ago. That engine holds on to 0.8 quarts of oil when you do a normal drain and filter change. That's from Toyota's own on-line maintenance pubs.

 

[Eddie]

My Mazda CX7 factory manual states that the engines dry fill is 6.8 quarts. I and many can only refill 5.6 quarts after a one hour draining on level ground. This is a turbo engine and has a substantial oil cooler and the turbo is oil cooled.

 

[zulu]

Realistically, probalby 1/2 quart on average. My Malibu will take about 4.5 quarts in a 5 quart sump during changes. My Silverado is about 5.5 in a 6 quart sump. My only oddity was my old RSX that took 5+ quarts in a 5 quart sump. Keep in mind that not all oil filters hold the exact OEM dimensions so results will vary slightly.

 

[Cutehumor]

if you want drop of the used oil out, it ain't gonna happen. do not waste oil by doing a patman flush either. your engine will not know the difference.

 

[springs]

My F150 4.2 V6 engine holds six quarts of oil. When I change the oil, along with the filter, it takes six quarts of oil to refill the engine. It's true that millions of vehicles in the U.S. have oil changes done at quick lube places where nothing special is done, and they seem to run fine for 200,000 miles and even a lot more without engine damage associated with oil problems.