Fumoto valve and residual oil
 

Last weeked i had to pull my engine. I drained the oil from the Fumoto valve. After a bit, I decided since the valve might get bumped during the engine removal and transport, I took the valve out to replace it with a regular oil plug.

There was quite a bit of residual oil still in the pan. 1-2 cups?

And yes, I need a new drop light.

If I remember correctly it's because the threads of the valve itself stick up a little bit inside the pan.
Years ago on an LGT forum someone actually cut a notch in it so more drained out.

I cut mine down to the depth of the female threads.

And that drop light is just fine.

Yep. Guys do all kinds of things to get that last bit out. Notch the bottom, drill a hole, grind some threads off jack or ramp on one side to tip the car... The press formed thread insert also protrudes into the pan + 3/8". So even without the Fumoto, you're leaving a good bit in there. More than a cup, but probably not two?

https://killerbmotorsports.sharepoin...XQQlg?e=bFSoRa

Glad to see the New WRX FA24's pan has a better boss that's extended outward. Looks to have machined threads (vs formed) and there are more threads as well.

WRX top left, BRZ on the right...

https://killerbmotorsports.sharepoin...zu1Cw?e=PEehlj


How much of this really matters? Probably very little since at an oil change, you have almost a quart suspended in various places in the engine anyway. Just another reason to be vigilant with oil changes.

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Add an oil cooler and you have a whole additional quart not being drained.

And the unasked question. Does it matter??





General answer. Probably not. I change mine on a warm engine primarily to ensure that the oil is well mixed.

Even on an in-line vertical cylinder engine I never got all of it. On an “H” configuration? Fuggidaboutit

unless you're doing UOA at every interval its not super important.

more important is regular maintenance as needed.

so, wait. is it regular maintenance, or as needed?

Regular maintenance, as needed.

Mine regularly needs maintenance.

Same.

I uh... I do them at every interval. Done them since the car was new and put the fomoto valve in about halfway through the life of the car so far (45k miles). The extra oil that doesn't make it out... doesn't seem to make a difference :D

We tee in a drain valve, or if access is easy, just pull the lower line. OEM coolers tend to be more user friendly with a drain and decent access. Wish more aftermarket coolers did the same.

No. It's a fraction of what's remaining in the engine anyway.