php

Good point. I'll refrain from using it for short drives to the gym and take it out for longer drives on the weekends. What would you define as a long run?

yvesvidal

A long or good run is when all the fluids in the engine have been brought to their operating temperatures: Water 175 - Oil 210

Half an hour of running your car, will give you the perfect warm-up.

I tend to use my 997.1 for long distance trips and keep my old BMW for short trips and errands. It works better this way.

Yves

vbb

It's a thing, but I don't think it's a thing like the bore scoring scares we've seen out of the 997.1. Now there are droves of people on this board more technically inclined than I, but I have a 997.2 and can attest that it does drink some oil in between changes. Since I do not drive more than around 5K-6K/year, I just change my oil once a year (though I'm going to change it after track events now that I'm getting in to that). Honestly, I haven't kept a log book on it, but I do check my oil level at least once every few times I take the car out, and will notice I'll lose a bar here and there over time. When I notice it getting to the bottom one or two bars on the gauge, I'll add back in another quart. Actually what I'll do is add in another 3/4ths of a quart... drive it enough to get it nice and hot and check it again, and then add in the rest of the quart once I've determined that it's not at the top line, so as to prevent overfilling.

I will probably start keeping more meticulous notes about just how many miles I go between adding oil, especially after reading these threads, but I know it isn't an "all the time" sort of thing. Maybe a quart every 4 months or so (which is about 2000 miles) for me? Maybe a little less than that?

I do have sooty tailpipes though. It's on both sides though, not just one, and there's never any clouds of black smoke or anything like that. I just assumed it was the DFI, or the fact that Porsches just run a little safe/rich.

EMC2

gopirates,
Just another thought while your car is at the dealer.
Failed AOS can cause fouling of the spark plugs (if severe enough). Not sure if applicable in your case but it could be worth having the dealer check.

php

all of the above sounds EXACTLY like my car....hopefully that means it's more on the normal side and less of bore scoring

StormRune

My take on this is a little less absolute. It seems to me that some short runs are okay as long as you don't accumulate too many of those between vigorous longer runs at full temp to cook off any moisture buildup. As long you as get the engine up to full temp then the moisture problem should be taken care of. You should also make sure to use the engine fairly aggressively every so often for best engine health when it's at full temp. I might overdo that one! There is an article from Hartech talking about how this helps our engines especially with respect to carbon build-up (starting around page 57): (http://hartech.org/docs/buyers%20gui...20part%205.pdf)

Just don't turn off the engine immediately after a hard run, let the hot spots in the engine come back down to normal temps first. (I'm amazed at how many drivers I see come off a hard autocross run and immediately turn the engine off while waiting for the next run).

That said, I do use other cars for most of my short runs... but sometimes the itch to get out for a short drive is just too compelling.

rodH

Interesting thread as I have a 997.1 but looking at records 7k miles ago (about 18k on the clock) the pervious owner had a new oil separator installed and new plugs. I am at 4,000 miles on this oil (changing from 5-40 M1 to Motul on Sat) and never had an oil light go on, and level appears to be within the normal range, but it is a bit low. Judging by what Porsche considers "normal" it looks like I am in Great shape. Maybe the previous owner had a bad AOS though? (It was covered under the 3rd party warranty).

EMC2

gopirates,
How did everything go? Do you have the car back?

hockenheimr

I think the car tells you when you haven't checked the oil level in a while. I had a similar warning come on (but mine said something like 'check oil level'), and in the end I didn't need to add oil.

gopirates

I got the car back. They had to order the AOS and with my scheduling it'll be over a week before I can get it back in for the repair.

I do need to ask about the plugs. I'm doubtful they will cover that unless I have a very compelling argument.

Iceter

Are you dealing with Leith or Southpointe? Please keep me updated on your progress through this--including any discussions you have about your plugs.

I haven't had a serious issue with my car and I know that Southpointe has been much better than Leith about dealing with my minor issues and routine services. I am curious to see how either one of these shops deals with an issue like your oil consumption.

stevepow

Yes, and then when you finally do drive a good distance, all that junk burns off quickly making it appear like sudden oil consumption. My e39 M5 was extreme like that - I always carried 2 quarts with me on longer trips (400 miles or so) and would often need to add most of it.

I still keep oil in the frunk of the 997.2, but lately I hardly ever need to add much - not like when it was new and I was adding quite a bit of oil often.

Ericson38

You would think that for a 3.6 liter engine to continually consume 1 qt of synthetic oil in 700 miles, it would foul the plugs and carbon up the ring pack !

You would think....

I had a 283 (4.7 L) V-8 2 bbl 57 chevy with power glide 2 speed auto that ate 1 qt havoline 30 W in 500 miles in texas in the '70s. I could not stand it, so rebuilt it. It was a 2 door HT. Combustion chambers and rings totally gunked and stuck. It was an air-oil pump with some gasoline thrown in as a solvent.
Yes I ran hotter plugs, but the smoke was always around the tail pipe.

Oil burning lowers octane, the more you burn, the lower the actual octane of the mixture.

Think about this scenario, burning an OK (gets a pass forever) qt. every 700 miles, octane is lower now, we get on it, and pre-ignition arises, and open deck allows for an eventual fracture (D-chunk).

Maybe one reason Mobil 1 is specified, leaves low ash in combustion chamber and has very high detergent, but no so good on anti wear. Who knows the compromises that were made and then the weak points addressed in the oil formulation.

Philster

Well, you could burn oil at good rate and not completely foul the plugs to the point of significant misfire.

You might have sooty plugs, and might be losing some grunt, but it's not unheard of to burn oil and still have a pretty decent running car (optimal? No. But ok).

Some plugs are 'hot' enough to get away with it. Some engines, which are predicted to burn some oil, will call for hotter stock plugs anyway.

From reading around, it looks like 997 oil burners tend to get away with a good rate of burn (even the ones with excessive rates) without excessively fouling the plugs in many cases.

.

gopirates

I'm working with Southpoint. I take it back next Monday to do the AOE due to my scheduling and they said they would look at the plugs. I'll keep you posted.