What's the purpose of the "hole" at  Oil Filter Base for Subaru Forester?

 

I mean this "hole" at the oil filter base:

shot in 4K high resolution if you can't see it very clearly:

Edited February 4, 201610 yr by drdavidzhang

Drains off all the oil that comes out of the filter, I think. No idea where it drains *to* though. Probably just to the ground.

ugh - I KNOW I read a thread about this issue.

 

pretty sure id doesn't 'go' anywhere. I THINK I recall the thought was, any dirt/debris would collect in that depression instead of possibly running in to the oil passage.

this depression is very small though, this small capacity, what can it do? Did anyone confirm this speculation of collecting debris with a dealer?

In this video it looks like a depression- until at 5 minutes it looks like a hole because it's got black oil in it.

 

 

Edited February 3, 201610 yr by CNY_Dave

If it doesn't seem to have any purpose and it's and depression rather than a hole maybe it's just something from the casting/machining i.e. to make it so a machine can handle the part or something like that.

If it doesn't seem to have any purpose and it's and depression rather than a hole maybe it's just something from the casting/machining i.e. to make it so a machine can handle the part or something like that.

 

interesting theory, well so many different theories so far about this.  It looks like pretty smooth and polished, so it must be with some purpose.

I cleaned that hole/depression, so at least I can confirm that it is depression without any leaking.  

Edited February 4, 201610 yr by drdavidzhang

If it doesn't seem to have any purpose and it's and depression rather than a hole maybe it's just something from the casting/machining i.e. to make it so a machine can handle the part or something like that.

Exactly. I have a 2016 Outback so I know something about this. It's been discussed at Subaruoutback.org. This "hole" is simply an oval dimple about 2-3 mm deep. Mostly likely the result of the casting/machining process said above. I filled mine with JB Weld to get rid of the depression so that dirt and spilled oil don't get in there. Of course that's really not necessary. Any dirt there won't get into the engine with the filter in place. I changed the oil on this car a few days ago and the top-mounted filter is really easy to handle.

There's some evidence online that a Toyota made similar to this has a nipple in a similar location. There are pics of an owner hanging a cup under the nipple to catch drips. Given Toyota's involvement with Subaru, maybe there was some crossover in tech - but fitting a nipple there was abandoned ?

Maybe someone can cast some silicone and start a cottage 'oil filter cover' business!

Here is a picture of the factory oil filter on the FB engine showing part of the hole. As I turned the filter very slowly and removed it, most of the oil in the filter drained down into the crankcase. There was very little oil left in the filter resulting in no spilled oil at all. The only oil left in the round aluminum tray at the base of the filter was on the mounting flange. Cleaning up was extremely easy, the easiest oil change I've ever done. I also installed a Fumoto valve shown in the 2nd pic.

 

There are many theories:

theory 1: a depression to collect sediment or residual oil when changing. this  depression keeps stuff from falling of flowing into the engine when you take the filter off.

 

theory 2: it's just something from the casting/machining i.e. to make it so a machine can handle the part or something like that. 

 

theory 3: subaru's future high end car has a sensor inside this depression so that it can detect oil leak :]

 

theory 4: it is for a different kind of oil filter

 

 

There are many theories:

theory 1: a depression to collect sediment or residual oil when changing. this  depression keeps stuff from falling of flowing into the engine when you take the filter off.

 

theory 2: it's just something from the casting/machining i.e. to make it so a machine can handle the part or something like that. 

 

theory 3: subaru's future high end car has a sensor inside this depression so that it can detect oil leak :]

 

theory 4: it is for a different kind of oil filter

 

I talked to my dealer, and he referred this to the service manager. Here is the reply:

"Hello David,

 

No one seems to know for sure. Looking at it most say it is number 2.

"

Nicely done Vasy!   Fumoto valve is the way to go!

Glad to see new models have easy access to Fumoto valve through hole in plastic toboggan....so I don't have to remove it every time I change the oil.