Re: GT4 Oil change - what a PITA POrsche!

Oh, the physical job is not tough at all, aside form the fact that the filter is waaaaay up there. Much like M96 / 986 oil change.


But .........

The lack of a dipstick is a serious issue IMO.
This is now combined with an oil measurement system that will only work if the car is a) fully warm, b) level and c) hatch closed.

Does anyone else see a problem here? There is no way to confirm that you have sufficient oil to start the car and warm it up so you can get a measurement.

Soooooo i measured and prayed. I filled with 7.5 US qts including what i put int he new filter holder. his ought to have been 1/2 qt low. In the end i hit it spot on - exactly full. This sounds good but is not. It means that either the specification is wrong or 1/2 qt remained. Since the oil was only 140 deg when i backed into my chilly garage (maybe 54 degrees) the latter is likely - but it is always an unknown and i dont want to star a car with insufficient oil and starve it.

Rant off. I doubt anyone has a solution - but if by any miracle you do, fire away.

Anyway, clean, full, and happy. But a bit unsettled.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

I agree that the removal of the physical dip stick is a pain. I don’t trust the electronic measurement and so while the oil/filter change itself is pretty easy on my 997, I measure how much oil is drained and then put a little less than that in and go from there.



Edited 1 time(s). Last edit at 11/28/2021 11:40AM by CarreraLicious. (view changes)

With my 981 (I know, not the same engine), I have my indy put in 7.5 liters of oil, which the manual calls for. It does take a while before oil level shows up any time you open the trunk. Once warmed up after an oil change, it usually shows a bit low I usually drive the car for a few days and find the level seems to go down a bit after after a few days of driving. I then top it up about 400 ml at time (about 1 unit of measure on the gauge). so it indicates full (not overfilled of course.). Up to this point at 110K km = 68K mi. I haven't had to add any oil between oil changes once I have it topped up.

Once the engine has been warmed up and you get a ready, you can actually check the oil level while driving or even when cold in the garage - until the next time you open the trunk of course.

why on earth would opening the trunk affect the oil level reading?

--
MY 2000 S, Ocean Blue, Metropol Blue, Savanah Beige.
Bought June 2000 - Sold May 2010

I even wonder if there is some double secret way to measure it that only dealers know. I need to ask....

Grant

gee-lenahan-at-gee-mail-dot-com

Because that sucks! Or the trunk lid does... or WTF???

.. i didn't test the "trunk open" lockout, since i had to drive the car to warm it up anyway.
I did test it with the oil at 80, 100 and 120 degrees (F). No go.

Grant

gee-lenahan-at-gee-mail-dot-com

Quote
grant
.. i didn't test the "trunk open" lockout, since i had to drive the car to warm it up anyway.
I did test it with the oil at 80, 100 and 120 degrees (F). No go.

After opening the trunk, I find I have to drive 10 - 15 minutes before I get a reading.

I also meant to mention earlier that my indy told me that when the oil almost stops draining, to wait about 10 minutes and suddenly, you get another gush of a few cups of oil coming out. He lets it drain while he's checking the computer readout, brakes, bearing play and other stuff.

no gush. Just the ever slower drip. I suspect the retained oil was due to the slight angle my car was on (backed up onto ramps).

That would account for some significant portion of the 0.5L. No biggie, is 15/16ths changed.

G

Grant

gee-lenahan-at-gee-mail-dot-com

Quote
frogster
why on earth would opening the trunk affect the oil level reading?

You might have added some oil while the trunk was opened. - At least I'm guessing that might be the reason.

Guessing the % of ppl that change their own oil is even less than those that shift their own gears. In other words, to capture the revenue stream today's business model assumes dealers will conduct oil changes with their purpose built equipment, so manufacturers have little / any incentive to support home mechanics IMHO. In any case 'oil changes' and 'gas stations' will be quaint anachronisms in 30 years, so enjoy it while you can.

I drain the oil, change the filter, fill about 2 quarts low from the spec, check the electronic dipstick level, then add as necessary until the level is in the middle of the range. If there is cold oil that hasn't dripped down to the pan, the amount is never enough to make the actual level too high.

I have a manual dipstick and almost never use it.

The electronic dipstick does not register at all - simply provides an error message until:

1. fully warmed up (something like > 175 degF)
2. Level surface
3. trunk/hatch latched

There is NO [documented] WAY to get any measurement at all until you have driven the car.

Simple on a 986 or 987.

Grant

gee-lenahan-at-gee-mail-dot-com

I misunderstood. Some people get tripped up by the 986 electronic dipstick countdown and I didn't realize it was different.

Then look under the car before restarting. If the oil isn't all over the ground, it's likely safe to restart from cold.



Edited 1 time(s). Last edit at 11/30/2021 11:55AM by Laz. (view changes)

Assume oil is fully drained and consequently car is cold. You calculated, guess and add fresh oil, prime he filter cannister, etc.

now.....i what? Without staring the car?

Grant

gee-lenahan-at-gee-mail-dot-com



Edited 1 time(s). Last edit at 12/01/2021 09:11AM by grant. (view changes)

The idea is that a non-running car can only lose oil through leaks, (well, maybe some past the rings.)
This would be a way to get a basic, go / no go oil check without needing a dipstick, or instrument* reading.

The car will have to be started and run one last time before instituting the "oil puddle" procedure from then on.

At the end of its run and shut off where it will be parked for a while, follow whatever oil check procedure is proper. At this point, you have a "baseline."

If the car has been parked for, say a couple hours or overnight, and there's a puddle, try to determine if it's from more than say, a couple quarts-- whatever your educated guess tells you is dangerous. Look up at the belly panels, and the drain plug area, too, if it's visible.

I don't have the technical knowledge to suggest how to determine what's actually in the sump, but at least you won't be killing the engine in the meantime.

* Btw, when the car is cold I think the oil level display may be showing a "snapshot" of the previous (warm enough) reading.
Why it doesn't display "unavailable" or whatever, rather than the supposed snapshot is something I've yet to determine, but it seems to do with checking from dead cold versus insufficiently warm.



Edited 1 time(s). Last edit at 12/01/2021 12:32PM by Laz. (view changes)

.. confidence- inspiring. I fear many things. Over-filling (how much drained out?) Under filling (could it go somewhere? Well.. anything's possible [1].

I just find it ridiculous that the oil level, as measured, non-level and all, cannot be displayed.

and i suspect there is a secret work around if only i knew how to access it.

G

note [1] as an example iof unlikely things My track car motor is apart right now. Why? Ont he track a freeze plug in the right bank head, blew out at 7k rpms.

Nothing else. It just blew out. Was sitting, minding its own business, int he head when i pulled the valve cover (after pulling the motor)

point: unusual stuff can happen.

Grant

gee-lenahan-at-gee-mail-dot-com



Edited 1 time(s). Last edit at 12/01/2021 01:07PM by grant. (view changes)

Looks like it's attached to the bottom of the oil pan. From the diagram, it would appear that each of the sections matches the segments in the display.
[www.sunsetporscheparts.com]

IIRC, the actual oil level is capable of being read via the PIWIS system, rather than just the virtual dipstick.

I decided to est how the level display works under various conditions.

So i just walked into the (medium cold) garage and checked the level. It displayed, despite not being warm. I suspect it stored the last good measurement and somehow knows the car has not moved (but could have leaked, let's not go there).

Next I want to drive it, and park it on an incline and see what i get.

Some mechanic on youtube (so it MUST be right) made a comment about being a GT4 so it will tell me the level.....

Maybe a back door?

Grant

gee-lenahan-at-gee-mail-dot-com

It was either my sales guy, who's an enthusiast (tracked a 944,) and seemingly knowledgeable, or one of the dealer service people, mentioned the snapshot to me when I asked about the cold reading.
I read somewhere (another "read somewhere" ) that Porsche has specific parameters for the maximum longitudinal and lateral angles allowable for accurate readings. Even without these numbers I suppose there's validity in you determining significant level changes specific to your experimentation. Maybe a long straight edge, along with an iPhone's measurement app could at least help with the lateral angle measurement. (Thinking a 6 foot beam level across the fender tops, with some very thin padding, like old cotton t-shirt rags to protect the paint.) Maybe using the front to rear wheel centers and some trigonometry can yield the length angle.



Edited 2 time(s). Last edit at 12/03/2021 10:02AM by Laz. (view changes)

warm, and backed up on ramps in the garage. I will see if i get a reading. I will then take it down the ramps and try.

I may need to park it warm, and without starting it or otherwise letting its brain know, jack up the front or rear and leave it on blocks, and THEN try.

Gimmee a dipstick!!!!!!!!

Grant

gee-lenahan-at-gee-mail-dot-com

backed the car up ramps after driving a while. truned off.
Did stuff, came back and checked oil on whatever angle it was on - enough that 1/2 qt didn't drain when i changed the oil.

So the answer ought to have been "sorry, no reading" or "significantly low".

It was spot on. Which confirms that it took a snapshot and played it back.

====> IT LIES!

It also calls BS on the "car must be level" although it may have still be "and warm".

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

It helps, too, if the oil got over 212 for a bit.

Water boils at 212, which is substantially higher than their "warm" spec.
( i don't know the spec, but i do know that it finally gave me a reading after the oil change at ~ 175 degF)

Moreover, it boils off slowly. It might take 15 minutes at, say, 230 degF to completely boil off water ( and acids).

On the other hand, the motor expands when hot, and changes the internal volume.
Any oil measured cold, will measure higher (fuller) when hot. Try it some time.
If your theory was correct, it would measure lower (boiled off volume).

I totally agree with i think your fundamental point though -- that getting a car hot and leaving it there is overall good for the motor.
My track cars always show immeasurable "dilution" in oil analysis.

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

... is in my owner's Manual.

It confirms, unless i missed something, that there is no provision to get a valid measurement under normal oil change conditions.

It is the first time i have seen mention of the residual oil in the integrated sump.

thanks!

Grant

Grant

gee-lenahan-at-gee-mail-dot-com

That is the way the oil measurement system works with my 981S. I find that the oil reading can change while driving - likely when it's close to the limit between two of the segments

There is a lot more detail there than what's in the owners manual. One thing that I really found interesting is the amount of oil in the engine (10.6 qts, 10 liters) and the amount required for an oil changed (7.9 qts, 7.5 liters) That would indicate that about 2.7 qts or 2.5 liters of old oil stays in the engine at every oil change. I do find that mine takes more at an oil change than what the manual says (7.5 liters with filter as per manual). I have my indy put in 7.5 liters at a change and I usually have to add about 0.8 liters to bring it up into the top (4th) segment. I prefer to bring it to the full level myself, as measured over a period of a few days or a few hundred km of driving to ensure I don't get an over-fill.