Re: So after having the oil changed

For those of you who've done oil changes on your 981's. How accurate is the measurement info in the manual? I noticed that the capacity is listed at less than it was in my 987. Book says 1.98 gal. (7.5 liters) ...um seems like about a tablespoon short of 8 quarts. Was that your finding when you did/had it changed? The 987 capacity was 7.75 liters.

Just wondering as I have an oil change booked for this week and want to ensure it doesn't get over filled.

Of course, people's measurement methods may vary, and folks may not account for filters etc.

I've never had anything newer than a 986 either. My car additions in fact are getting OLDER, nto newer

Grant

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

I found my 987 always matched the book, but like you, have heard that some engine vary.

I just want to make sure it doesn't get over filled since I'm having it done by the dealer while the car is under warranty.

it is based on at least two drain times: 1 hour, or overnight (12 hours). There are two refill amounts one for each drain period. (Oh, the engine temp I believe is also specified.)

The stated amount of oil is added to the engine and the level checked. I have not seen the factory manual section on the newer engines but I have seen this for my 996 and the amount to be added after the engine is drained of oil when up to temp for the specified amount of time (20 minutes IIRC) is 7.8l. After this amount of oil is added -- the oil dispensing gun at my dealer reads in 0.01l -- the engine is idled until it is hot enough to check the level -- the Turbo oil check requires the engine be hot (at least 170F) and idling and the car on level ground -- and the manual says the oil level reading should be at the max. line, not any below and certainly not any above.

If you ask the tech he might print out the section of the manual that applies to your car's engine and its oil change procedure. The level you might get from the parts department. Ask. Bring your car's VIN. My info is fluids (and parts) are tied to the VIN.

oil level is ready with the engine at operating temperature, but the manual doesn't say exactly what temperature that is. I take it to mean the coolant is at 90C (194 F) where it sits once it's warmed up and oil temperature also up around that point. Car is usual has to sit on level ground and with engine switched off.

My suggestion would be 7.5L and then adjust after the fact.

As I mentioned in an earlier thread, when I had the oil changed a few weeks back, the car showed 1 bar low after it was thoroughly warmed up and measured on a level surface after being off for 5 minutes. I did this a couple of times to make sure I got a consistent 1 bar low measurement.
After that, I added a small amount of oil to bring it up to the full line and it only took a few ounces --I think 4 oz.--and it was full.

I'm glad I did it in small increments; if I took the digital gage at face value, I'd have added .45 Qt and might have have been overfilled.

Thanks, Mike. That's what I was thinking. Manual says 7.5L with filter change, so might get them to put in 7.25L. I think if it's down one bar, it would likely take 0.4L (0.45qt) to fill it. That's what one bar is suppoed to represent.

The correct info is given in the factory reference manual for the car or in a TSB for a specific range of VINs

The engine should not be filled by what the oil level reading reads but what the dispensing gun reads. The oil level sensor could be defective or wrong. The oil change is the only time it can be checked by adding a specific amount of oil and confirming the reading agrees.

You would think that unless they make some major change to the engine design or change the size of the oil pan, all the engines would have the same oil capacity.

Quote
MarcW
The correct info is given in the factory reference manual for the car or in a TSB for a specific range of VINs

The engine should not be filled by what the oil level reading reads but what the dispensing gun reads. The oil level sensor could be defective or wrong. The oil change is the only time it can be checked by adding a specific amount of oil and confirming the reading agrees.

The implication of your post Marc, is that we should not be doing our own oil changes.

I found the owner's manual to be pretty spot on given the amount I carefully fill with. Now that I have done the procedure a few times, I suspect I will recognize if something is amiss.

Peace
Bruce in Philly



Edited 1 time(s). Last edit at 11/05/2013 12:00PM by Bruce In Philly (2000 S Boxster, now '09 C2S). (view changes)

And pretty much zero shops follow that procedure. They over-fill all the time.

I have a museum piece with this metal thing that can double-check the sensor. I just changed the oil in both cars, one lat night. in both cases the full corresponds exactly to the manual, and the flexible metal thing-y ( do you recall what we used to call them?) and the sensor agree. The sensor is much more sensitive to level, temperature, and the phase of the moon however.

BTW i'm sending the 986S's oil out for analysis after 10 track days and a total of 5300 miles, most of it highway to places like Alton, VA and Watkins Glen, NY. It looked and felt very good. Nice viscosity, no milk-shake. Just dark. I more and more believe that oil that stays at high temperatures for elevated periods lasts much better. This just had 550 miles to VIR, 3 track days, and 550 miles home. Water in the oil? Not likely.

Grant

Grant

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

other than the shop, the tech, simply doesn't know how to do the job right or doesn't care to do the job right.

High prices for low service. That's their motto.

And many techs and shop managers want productivity. A book hours 5 hour job should be done in 4. Everyone makes more money. Especially when it results in more business later to fix what was broken. No smiley.

You seem to have a very different experience, and are fortunate.

Grant

Grant

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

That and you recognize that if you dump in the correct amount and the reading is off to recognize the oil e-level system is probably defective rather than dumping in more oil if the reading is low or removing oil if the reading is high.

When I change the oil I count the bottles twice and put in what I know to be a bit less than what is called for. The oil level reading is then low but not by much and I then add the fraction of a quart to bring the level up to its max reading.

When I picked up the car "new" from the dealer, the oil gauge showed overfull. In successive oil changes with my indie mechanic, it always showed overfull and both the dealer and the indie told me not to worry about it. Once these threads started arising, the indie and I carefully measured the exact oil capacity shown in the manual and sure enough, the gauge showed overfull. Then the next time, we stopped about a quart less than the amount in the manual just to make sure the gauge was actually working. It was. We then added the rest of the amount to what the manual says the car takes, and sure enough, it was overfull again. Marc says the manual is incorrect. I don't know and any more, I don't care. My car doesn't burn oil, it never smokes, it runs great, and both the dealer and the indie mechanic tell me not to worry about it. Maybe the gauge is inaccurate. Frankly this whole conversation is becoming so OCD that I'm going to ignore it and just let the pros put in whatever kind and amount of oil they think it takes. Heck, the @^ engine might blow up and make it all a moot point anyway.

is telling you the overfill doesn't matter they are to put it gently feeding you a line to get you to go away.

Whip out the owners manual (you can use it as gospel when it suits you) and quote the section that says to not overfill the engine with oil. If you get any push back tell the dealer you will write to PCNA and let it know what is going on and ask it to recommend a place that can properly service your Porsche. Dealers hate these letters cause it put PCNA on alert the dealer is servicing the car improperly (and like cockroaches if you see one there are many more you do not see, there are many more PCNA doesn't hear about) and if it gets too many of these it could call into question the accreditation of the dealer. If the dealer loses this it loses the franchise. Read it loses money. Big time.

For the indy shop, show the shop owner the manual too and insist from how on it not over fill the engine with oil. If you get any push back mention the Bureau of Automotive Repair (at least this is what it is called in CA). I mentioned this once to a body shop and you thought I had stabbed the owner with a sharp stick. He really reacted and in the way I wanted.

Might ask how do you know the engine doesn't burn oil when the engine is overfilled with oil? There is no way to know by how much the engine is overfilled with oil: The oil measuring system is not designed/intended to measure oil over the proper amount only to show there is too much oil in the engine. So the engine could burn almost enough oil to bring the level down to just the max line.

I should pull out the owner's manual and show them where it says not to overfill. Would that be the same owner's manual that told them the exact oil capacity that they just measured and put into the car? The same manual that you yourself just said contains incorrect information? How do you or I know that the capacity in the manual isn't actually correct? How do you or I know that the gauge isn't simply inaccurate on the optimistic side? Neither one of us knows. But what we do know is that my car doesn't smoke and highly qualified mechanics have told me not to worry about the supposed overfill. You speculate that they are telling me this just to get me to go away. That doesn't make sense. If they overfilled the car and there was a problem, THEY would be the ones to blame, so it would be pretty stupid just to get me to go away. And you ask, how do I know my car doesn't burn oil? Well, it doesn't smoke at all, and it almost never even makes the characteristic smoke at startup. And, if it was burning oil, it would eventually burn up enough oil that the gauge would drop? Because I have proof that the gauge itself DOES work, and yet the oil gauge has never dropped below overfull one time in the last 5 years of driving, one year between changes. My car runs great. No problems at all. It seems infinitely more probable that the capacity in the manual is correct, the dealer and the indie are correct, and the gauge is simply optimistic. My wife tells me to stop reading these forums because all it does is make me fearful of my own car. I think she is right, and this thread is a prime example.

Quote
paulwdenton
I should pull out the owner's manual and show them where it says not to overfill. Would that be the same owner's manual that told them the exact oil capacity that they just measured and put into the car? The same manual that you yourself just said contains incorrect information? How do you or I know that the capacity in the manual isn't actually correct? How do you or I know that the gauge isn't simply inaccurate on the optimistic side? Neither one of us knows. But what we do know is that my car doesn't smoke and highly qualified mechanics have told me not to worry about the supposed overfill. You speculate that they are telling me this just to get me to go away. That doesn't make sense. If they overfilled the car and there was a problem, THEY would be the ones to blame, so it would be pretty stupid just to get me to go away. And you ask, how do I know my car doesn't burn oil? Well, it doesn't smoke at all, and it almost never even makes the characteristic smoke at startup. And, if it was burning oil, it would eventually burn up enough oil that the gauge would drop? Because I have proof that the gauge itself DOES work, and yet the oil gauge has never dropped below overfull one time in the last 5 years of driving, one year between changes. My car runs great. No problems at all. It seems infinitely more probable that the capacity in the manual is correct, the dealer and the indie are correct, and the gauge is simply optimistic. My wife tells me to stop reading these forums because all it does is make me fearful of my own car. I think she is right, and this thread is a prime example.

The owners manual in the case of overfilling you can rely on. For proper fluids and capacities these change and the owners manual is not updated to reflect this.

The oil capacity in the owners manual may be correct, but the oil capacity the techs go with is what Porsche provides through its (now) electronic/digital information system.

As I've been told the fluid capacities are tied to the VIN and it is this amount the tech should go by. This amount is based on the engine being at least up to a certain temperature and the drain being done for one hour (in the case of the DFI engines) or overnight. There are two different refill amounts given based on the drain time of one hour or overnight.

The oil gun reads out in 0.01 liters and the oil is stored in an area that remains temperature stable. So the amount dispensed should be accurate.

The amount dispensed then is known. This is then used to verify the reading is correct.

In the case of your car it could be the tech is just not doing his job correctly and dumping in an assumed proper amount of oil.

As an aside: I had this problem with my Mustang which required 6 quarts of oil vs. 5 quarts for the models prior to it and for some time every time I got the car back the oil level would be low because the tech (I use this term lightly) was on auto pilot and just dumped 5 quarts of oil into an engine that required 6 quarts of oil.. in one case I called the dealer from work and had the car towed back to the dealer at the dealer's expense to have the oil level corrected and afterwards that dealer always put in the correct amount of oil.

Or -- getting back to your car -- or the oil level system is not working properly and is showing the wrong level with the correct amount of oil in the engine.

So when you get told the overfill is ok it is either to paint over incorrect servicing or the possibility the oil level system is not working properly. Thus I have to call into question the classification of highly qualified mechanics who obviously can't do something as basic as changing the oil in your car. Either they do not add the right amount of oil or they do and then do not react to the wrong reading of the oil level system.

As for burning oil lots of engines consume oil and do not exhibit any signs of this by smoking at any time. The only thing you have to go on to determine if the engine is consuming oil is the oil level system and monitoring the oil level over time in a disciplined manner. (Mainly taking into account temperature variations for those systems that can measure the oil both cold and hot and taking into account the levelness of the vehicle.)

But you do not know that the car's oil level system is working properly.

The engine could be using oil -- which is normal -- but the oil level system does not reflect this. One reason could be the level is way too high -- say a quart -- and while some oil gets consumed not enough gets consumed to bring the level down to even the max line. Or the oil level system isn't working properly and while the oil level drops the oil level system doesn't register this.

My tech contacts tell me oil level system failures are rare. One tech could only remember coming across one car with this problem. The failure mode was there was no reading at all. However, since talking to some techs about this I have learned there are other failure modes. After taking one of these sensors apart I can see where the sensor wiring could come loose and move about and thus result in a varying reading. There have been online a few reports of just such behavior.

Look, my goal is not to make you afraid of your car. That is the last thing I want. The intent of my posts has been trying to help owners maximize their enjoyment of their car by among other things taking proper care of the car, and avoiding the often crazy recommendations well meaning but woefully misguided people offer up.

Really my advise has been to in almost all cases adhere to what Porsche recommends. I do deviate from what Porsche recommends though to suggest owners follow a more frequent oil change schedule (and consider more frequent changes to other vital fluids as well) and to always have some reasonable amount of empathy for the engine and other vehicle systems and that's about it.

It might surprise you but I agree with your wife. Your wife is on to something in that most Porsche forums are becoming forums of horror for Porsche owners.

I am trying to limit my participation simply because I can't stand to read the scare stories in some cases offered up by those who have the most to gain from frightening Porsche owners and I do not have the time to offer some balance, inject some sanity. In some cases it appears a goodly number of owners prefer to be scared.

So if you fill it COLD to the fill line, its over-filled.

True for any motor since no manufacturer can guess what cold temp you will fill or check at. But they know hot - its regulated by the thermostat ( mostly).

Grant

Grant

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

but I recall Porsche engineering's reason not to check the level of cold oil that's been in the engine is that water vapor condenses and mixes into the oil, thereby increasing the overall volume.
Just thinking: why not go by weight and not by volume? Establish a precise weight for the total vehicle, with exact gasoline, oil, coolant, washer fluid, etc., empty the oil per the factory procedure, finally putting the car on a very sensitive and calibrated scale to measure the new oil fill to the ounce!



Edited 1 time(s). Last edit at 11/06/2013 12:18PM by Laz. (view changes)

I think they want you to measure it hot for consistency. When the oil is heated, it expands, so cold oil in a cold engine will give you a lower (depending on how close it is to the lower/upper segment) reading than if the engine and oil are hot. I actually saw that happen yesterday after I got home with the engine at operating temperature. A couple of minutes after shutting off the engine, oil level showed full. I decided to take another reading a couple of hours later and it showed being down one segment.

G-man...sometimes your Boxster obsessive-compulsive disorder just amazes me.

Don't overlook to factor in ambient temperature, coefficients of expansion, specific gravity, density altitude, relative humidly, gauge calibration error, instrument cluster calibration, oil viscosity and weight, level of car, rise of ground, time of day, distance from equator, parallax viewpoint reading.......

....and this oil-level adjustment device, just for you:



"A mile of highway will take you one mile. A mile of runway will take you anywhere."



Edited 1 time(s). Last edit at 11/06/2013 01:39PM by Gary in SoFL. (view changes)

Not hard.

and dont let other measurements confuse the issue. people parked on rough dirt at the track are always fretting.

"oh no, i'm over-full!, or under full!"

Both? Really?

winky.

Grant

Grant

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

Haven't checked with my 981, but my 987, the sensor must have been on the left side of the engine. If parked with the right side lower, the gauge showed oil low and when right side was higher, it read high.

1. the difference between cold and hot in my car varies from one to two graduations (depending on the temp difference). Hot is the proper measure.

2. The water accumulation is very true - i've seen it in spades (like a quart out of 4 1/2) in my mom's car that was putted to the gym or the supermarket each day and rarely got hot. Drive it on the highway for an hour and a quart vanishes, yikes!

Grant

Grant

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

I had the dealer put in 7.2 L of oil at the change. I pulled over a few miles after leaving the dealer into what looked like a level parking lot and checked the oil level. It was 1 segment down. Drove the rest of the way home (about 60 miles, air temp max 35 F) and checked the oil level after parking the car in the garage. Oil level still showed one segment down. So I added 0.3 L of oil. After that, the gauge showed full.

So it looks like the 981 manual, which says 7.5 L for a fill, with oil filter, is correct.

My 987 has a different capacity, but the book is packed away for a move so I can't access it. It holds 8.25 or something like that. What I remember when this came up a couple of years ago, we deliberately added 7 qts or so to it, just to see if the gauge worked. It did -- it showed low. We then added the rest of the oil equivalent to what the manual says. Guess what -- gauge showed overfull yet again. Just like every other time. Either the gauge is optimistic or the amount in the manual is wrong. I think it's the gauge being optimistic since I have no problems with the car and nobody but Marc seems to think the manual is wrong. It's an electronic gauge, it's not going to be perfect. Marc thinks I don't know how much oil is in the car, but I do ... it has exactly the amount it says in the manual, as duly measured by every mechanic who ever changed the oil, and under my own direct supervision the last three times.

At 10,000 miles, I had my second oil change performed by the dealer. For about 1,000 miles everything was normal. Then I got an overfill warning after a "vigorous" drive. I called the service tech and he said the gauge is extremely sensitive and it was not unusual on the 981 and not to worry about it. I had no smoking or other signs of an overfill. After about a week the warning light went away. This reoccurred once more for about a day at about 1500 miles after the oil change. No re occurrence since then.