Would you say that the notch on the dipstick to be a point of reference in the case of overfilling? If so, is it to scale with the distance between the L and F marks for checking when the engine is cold? Or, is the notch on the dipstick to reference proper oil level when the engine is at normal operating temperature?

 

As I understand Subaru's plan for the dipstick, the notch is normal "Hot" reference. It works that way for mine. The only thing I would say is a little odd is how the front and back of the dipstick will read differently than each other..........The back side of mine generally reads a bit higher, especially when cold. I just use whichever side is higher, since mine is not an "Oilaholic".

 

I cannot recall if the reverse side of my dipstick has any markings on it or not. I asked my question because I prefer to check oil level after the car sits overnight. In general, I will lose approx 1/2 qt. between changes, which are at 5000 mi intervals. As I get closer to the change interval I will check it a little more frequently, sometimes while warm out of necessity. Good to know that all of the old oil is draining out, as I add the full 6 quarts the manual specifies when refilling. Every 3rd or 4th change I will drop the entire pan just to see what escapes the filter. Fortunately, have yet to find anything metallic shining back at me.

 

Definitely different, but that's what makes them so endearing.....especially when it's time to purchase replacement parts lol!

 

If they build an engine so sensitive to oil level, why can't they design a dipstick that you can read?

 

Agreed on that too.

I decided to go a bit further to explain (to me if not to others) why the front and back of the dipstick show different oil levels. My explanation above had some weak points, namely, that the dipstick is thin, so the exaggeration in the diagram above doesn't really cut it. But a bit of experimentation does:

A measuring cup with some engine oil, and a simulated dipstick:

With the "dipstick" inserted into the oil:

And a magnified view of what is happening:

The effect on the underside of the "dipstick" is caused by surface tension of the oil, and the tendency of liquids to move up a solid when the enclosed angle is small. In this regard, I had the same effect using water.

As in my earlier post, if the dipstick is inserted with the right orientation (so that the marked side is "up"), the level of the oil will be indicated properly on the marked side.

 

Folks keep in mind that a dip stick regardless of what its in - 1940's tractor or a 2014 Subaru is a very simple device to show if you have oil or not. A dip stick that enters the oil at a angle is not going to show a big enough difference in the amount of oil to make a difference to the engine (assuming the vehicle is sitting flat to start with)

A quart low or even nearly a quart high on a system that holds 4 quarts is not going to cause issues for the engine however it will shorten the life of the oil and in extreme situations cause issues with the oil getting picked up or in case of an over fill oil getting into things its not suppose to get into. The oil splashes around in the pan and depending on how extreme the vehicle angle is the higher the chances of having an issue when the oil is down some or too high - the dip stick simply points to the happy zone.

 

One thing that should be noted, is that the dipstick is simply a reference tool...put four quarts of oil in four different cars and you're most likely going to get four different readings. They are not "calibrated" at factory...they are simply a guide.

I've owned a lot of different vehicles, and regardless...put the required "amount" of oil in and the level will read higher or lower than "full". At one time I would "calibrate" the dipstick by making a new mark at the "full" level, but it really makes no difference in the long run.

 

You guys are overly concerned about this oil level stuff. Drawing diagrams of how the stick enters the oil. lol

 

for people with turbos, that dipstick is all that exists between life and death.

and overfilling / consumption is a real problem for some people. ...and they should question if they ...or the stealership or independent mechanics are reading the stick correctly.

there have been allegations of stealerships overfilling and writing down consumption so they can swap engines in 2013 -2014 cars.....2010 and newer H6 cars have a extra notch high on the stick and some people misread that as being the full mark
despite it being a quart over the full mark.

_______

and this forum does have a good supply of people that care,...I am happy @plain OM made the funny pics and labeled them.

I think in the future Lt. Commander Data should swap Issac Newton out for Plain OM, it would be a much better game.

 

maybe, but thanks for necroposting. in this thread I saw some nice diagrams and photos that explained something I've wondered about for years.

 

2016 Outback 2.5i cold engine factory fill after 1200 miles. Note no notch on dipstick as earlier years were equipped. On hot engine after stopping long enough to pump gas the level is midway between the holes. But cold is well over the top. That is the opposite behavior claimed by earlier posts in this thread.

 

..to me...this is just fine...

 

Ah h3ll...I’ll just keep on doin what I do...fill it till it reads full on the stick.

 

Good plan. A little over, a little under doesn't mean a hill of beans.

 

Mine is only a year old, why would I bother to check the oil?

 

:grin2:

 

The main thing is to check your oil between oil changes at some regular interval and to make sure that there is oil in the engine!

 

Attached is a page from the Gen 5 (2015-2019) service manual. Notice, the Gen 5 dipstick has no ambiguous “Notch mark”.

 

One thing that I have commented on here and elsewhere is what I presume to think is an allowance for fuel dilution that Subaru and other automakers such as Hyundai have built into the oil capacity recommendations with their engines that use direct injection. For example my Hyundai 1.6L Gamma GF4D GDI engine has an oil pan capacity of 4 litres (4.23 quarts) yet only recommends a fill of 3.8 quarts total with 3.5 quarts in the sump and 0.3 quarts in the oil filter (3.5 litres total). So if it can handle and extra half quart or half litre of oil in the sump why not utilize it? Considering the amount of fuel dilution and carbon soot accumulation in the oil upon draining it I deduced why their might be an allowance figured in.

The Gen 6 Outback has a 5.07 quart sump on both the turbo and non-turbo engines, yet the recommended fill for the non-turbo engine is 4.4 quarts. Again I suspect that this is about a half quart allowance for fuel dilution and products of combustion that find their way into the crankcase through blowby. Perhaps the turbo engine, with its fill recommendation of 4.8 quarts, allows for an additional 0.4 quarts because it ends up going through the turbo.

I would caution against overfilling either engine too much because of foaming that may occur as well as that extra oil with fuel dilution, etc might tax the engine seals and contribute to things like head gasket failure.

 

Yes I think the problem is exacerbated when people park with the car sideways on a slope - oil that would normally drain back into the crankcase remains in the backside of the cylinder bores. I think some Ascent owners would have clouds of smoke (oil burning) when they re-started cars that were left overnight like that.

 

I have always gotten oil changes at Subaru and they always have the oil level slightly above the full mark. 100's of thousands of miles on the fleet and never an issue when slightly above the F mark. The fleet as a whole is nearing 400K miles

2003 Subaru Legacy 144K when retired (rust went to town on that car) no noticeable oil consumption
2010 Outback 156K and still kicking it no noticeable oil consumption
2014 Legacy 83K 1/2 quart every 6K

 

Just a reminder that although Subaru no longer puts the "hot" notch on the dipstick, when hot the oil level will be above the cold full divot, and it may appear 1/2 quart too high.

 

Japlish we called it. Working in video the Sony camera tech manuals were full of it. My last service the new service guy who I thought was a great improvement and came off the tools and previously performed services told me he would check the oil soon after filling and if he left it a longer time it would be "way over" (normal). Don't know what you say to this stuff. I assume the test drive is the last thing done so the engine is likely cold-ish. So he is completely is at odds with the above graphic. Mine is a no notch stick.