Porsche and the mysterious oil check dance

[Bill in Bama]

I started to put this post onto my recent oil change thread, but decided it needs its own topic since all of us with more "modern" Porsches face this dilemma sooner or later. That is, checking the oil level after an oil change. I'm old, I keep reminding you (I don't have to remind myself any longer, it is evident every morning!), so I clearly remember changing oil in my various vehicles and pulling the dipstick to check the level after adding the new oil to the crankcase. (My brother helped me change the oil in a car my grandfather bought once and poured two quarts in the carburetor before I caught what he was doing, the top of that engine was well lubed! But that's another story) Those days, sadly, are long gone, due mostly to emissions rules but also to the bean-counters that govern most everything that goes into a new car (or doesn't).

So, I had finished the oil change in my '21 GTS 4.0 (putting in 7 quarts only) but the weather was really crappy so i didn't drive it right away. In fact, the car sat for 3-4 days until we finally had dry roads. I took a short trip up Lookout Mountain and back, roughly 15 miles total, with no revs above 4000. I could not get a reading on the oil level. I parked in the garage and let the car sit for five minutes, then tried again, but still got the "unavailable" notice. I waited a few more minutes but still nothing. I had not opened the rear hatch during this process. So, the next day (Sunday) I drove to church and to a restaurant afterwards, no warnings, not oil level either. On the way home the oil temp was up above 200 so I revved above 5000 and immediately got the yellow low oil warning, stop immediately and add oil! I had prepared for this, had a quart of oil in the frunk, so I pulled over at the first chance and added the oil, not quite the full quart. I got back in and no warning, but STILL NO OIL LEVEL! I've occasionally had this happen but never to this extent. I followed the letter of the instructions in the manual but no luck this time. I'm open to any suggestions, but I've read countless posts about how they work or don't work, but I'm willing to try again. I expect this morning that once the oil gets up to temp and I've driven a bit I'll be able to get a reading, but who knows?

[Southbama]

I feel your pain Bill. For my next oil change, I am going to try to add oil without opening the rear hatch(if possible) and hope to get an immediate reading.

[Larry C]

I would probably go to the dealership - they should be able to sort it out and I doubt they would charge you.

[Bill in Bama]

I feel your pain Bill. For my next oil change, I am going to try to add oil without opening the rear hatch(if possible) and hope to get an immediate reading.

Boy, I've gotta see a video of that! You must be a contortionist! I probably could have done that in my 20's and 30's but it ain't gonna happen with this old bod!

[Bill in Bama]

I would probably go to the dealership - they should be able to sort it out and I doubt they would charge you.

Oh yeah, the car's under warranty and I'm sure they would check it out (with an appointment a couple of weeks out), but first of all its 55 miles to the dealer and second of all by the time the appointment rolls around it will have corrected itself I bet. Its just so frustrating that you can't get an immediate oil reading after changing the oil. I'm sure its possible the sensor is bad, but I'm betting its simply the over-complex system Porsche has designed into these cars and the extreme sensitivity of the pieces in play.

[Larry C]

55 miles? Yikes, I get your dilemma. Is there a good independent shop nearby? I’ve heard that the oil measurement system in our cars is confusing and tricky. Six months after I bought my car I got an alert to add oil. The dealership added around 1/2 quart which brought the level up to the maximum.

[Bill in Bama]

Nope, I'm in a really small town, nearest good indys are also 55 miles or more.
I'm not really worried about it, just annoyed. I know there's enough oil to protect the engine, but wouldn't it be much simpler with a dipstick?

FWIW I installed one in my Cayenne.

[blueline]

You've covered all of the situations where the oil level reading will not display - cold engine or oil too hot, car not level, open hatch. My manual also says it won't read in this situation: "Vehicle has been stopped after full-load operation
at high engine speeds". It also mentions that the engine must be off for at least one minute but I've seen it read otherwise. However, based on all that you've done it definitely should have displayed by now.

Even if the level was too low, you should have gotten a warning and if the oil level display was working, the display would have told you so too.

Also, if there's a fault in the display function itself, there should be a warning of some kind. However, since you're not getting any of that, I would definitely get to a dealer, especially since it's under warranty.

By the way, dry fill is 9 quarts. (Wet is slightly over 6 qts based on what I could find but I'd never do a wet change. For me, a top-off or a complete change only.) Porsche tech has told me to be careful adding oil and to use the indicator gauge when doing so, adding very small amounts at a time and checking frequently during the small additions. He said to stop as soon as it shows full. He stressed not to overfill.

Of course, that's all irrelevant and useless if your oil level display is not working.

[Bill in Bama]

Tim, I guess that's my biggest concern, I didn't get a warning for the first 15-20 miles driven after the oil change, and only after I exceeded 4000 rpm did I finally get the yellow warning signal. Obviously the level didn't really change any, just some algorithm or quirk finally kicked in.

I'm sensitive to over-filling, it's happened (supposedly) on my Cayenne twice, and both times I suspect it was a false alarm. I'm also aware the full capacity is 9 quarts or more( I've even seen 10 put forth as the total wet fill), and in my 981 I always put 8 quarts in with no problems, but I had two quarts left from the previous change plus a 5 liter jug, so rather than opening another jug I just went with 7 until I'd had a chance to drive it gently a bit to see what shook out. Now I know. Or do I?

[blueline]

Tim, I guess that's my biggest concern, I didn't get a warning for the first 15-20 miles driven after the oil change, and only after I exceeded 4000 rpm did I finally get the yellow warning signal. Obviously the level didn't really change any, just some algorithm or quirk finally kicked in.

I'm sensitive to over-filling, it's happened (supposedly) on my Cayenne twice, and both times I suspect it was a false alarm. I'm also aware the full capacity is 9 quarts or more( I've even seen 10 put forth as the total wet fill), and in my 981 I always put 8 quarts in with no problems, but I had two quarts left from the previous change plus a 5 liter jug, so rather than opening another jug I just went with 7 until I'd had a chance to drive it gently a bit to see what shook out. Now I know. Or do I?

I'm no mechanic and no expert but I'm going to ask around and see what turns up. If I find anything worthwhile, even if it's a stretch, I'll let you know.