Fumoto valve - which one? F-108?

hello all,

considering to replace the plug with Fumoto valve at the 1st Oil replacement.

which Fumoto valve model to use?

is this recommended http://www.fumotousa.com/parts.php?partname=F-108&partnumber=25

thanks

Fumoto valve allows solid debris (like metal particulate) to accumulate in the oil pan....

Interesting and I don't disagree with that.

Personally my preference would be a magnetic oil plug since then you can inspect it for unwanted traces. If you can feel the traces then you might have something going on. And the traces caught won't be passing around in the engine and cause wear on bearings and other surfaces which includes even the ones you can't feel.

Fumoto valve allows solid debris (like metal particulate) to accumulate in the oil pan....

I’m intrigued by that comment.

Are you saying this because the Fumoto valve sits slightly further into the sump than the end of the female thread of the sump plug hole?

By my measurements on our previous 2016 Liberty 3.6R the thread depth of the sump plug hole is 7.0 to 7.5mm deep (so the female threaded sump plug hole isn’t flush with the inside of the sump, it protrudes quite a distance into the sump), whereas the Fumoto valve measures 10.0mm from the supplied blue gasket to the end of the Fumoto valve thread. So the Fumoto valve protrudes into the sump 10.0mm from the outside of the sump whereas the female threaded part that takes the sump plug (& Fumoto valve) protrudes into the sump somewhere between 7.0 to 7.5mm from the outside of the sump (2.5 to 3mm difference).

I wouldn’t have thought that 10mm vs. 7.0 to 7.5mm would make a lot of difference to particles being left in the sump. On the 3.6 engine it is probably slightly less than that difference due to the angle of the sump plug hole, the sump plug hole isn’t in the horizontal bottom of the sump pan, it is a bit higher up from the bottom on the angled side part of the pan.

Or are you saying this because the flow rate is less out of the Fumoto valve than out of the sump plug hole without a Fumoto valve?

Low flow rate plus protrusion into oil pan. Pan cannot be completely drained.

The pan will never be completely drained of oil even without the Fumoto valve due to the protrusion into the pan of the female threaded sump plug hole. And the protrusion into the pan of the Fumoto valve compared to having no Fumoto valve makes little difference to the amount of oil left in the pan.

If concerned about the Fumoto valve protruding slightly more into the pan it can be easily modified like in the below attached photo.

The reduced flow rate of the Fumoto valve vs. no Fumoto valve is debateable in regards to leaving particles in the bottom of the sump. Perhaps this is a test I will carry out one day. My engine oil is drained when it is hot, & while it doesn’t come out as fast as not having the valve, it comes out of the Fumoto valve at a fairly fast flow rate.

How many particles are you seeing left behind? Do you have any photos you can post?

Modified Fumoto valve.

Not relevant to this discussion, but this is from the Fumoto website if anyone is concerned about Subaru’s approval.

It's more a question of the thickness of the material of the walls of the valve and the diameter of the hole in the valve than how far it protrudes into the sump. The lowest drain level would be about 2 mm (or maybe for you like 1/10 of an inch) higher than if you use an ordinary plug that you unthread since the plug/valve comes in from the side.

At least the plug came from the side on earlier models, I'm not sure if that's still the case on the FA/FB engines, but I suspect that's the case.

At least the plug came from the side on earlier models, I'm not sure if that's still the case on the FA/FB engines, but I suspect that's the case.

I’m not sure. Below is a photo of a WRX STi EJ257 engine sump upside down. The H6 3.6R has a similar angled part for the sump plug. I can’t remember what the FA20DIT sump on our SJ Foz XTP looked like.

any confirmation to use F-108 for Legacy base (none turbo) model?

thanks

any confirmation to use F-108 for Legacy base (none turbo) model?

I don’t have an answer, but this subaruoutback.org topic may provide one. That topic is about the Outback XT’s 24DIT engine but there was mention in there about the 2.5i. I don’t know how accurate the information is though.

Fumoto valve allows solid debris (like metal particulate) to accumulate in the oil pan....

I've been running one on my WRX for 5 years and haven't had an issue. I've sent my oil out for analysis once a year and I haven't gotten back a bad report.

On the plus side if you have a thin enough drain pan you won't have to jack the car up to do an oil change.