Matt(inMA)

I wonder if there are any statistical differences between the 3.6 and 3.8 liter engines with regard to oil consumption. I’ve got a 3.6 with ~ 20,000 miles on it. It used .5 quarts in the first 5000 miles and has not used any since.

Are the engines very different?

Matt

dgcate

gpk...

That was also my initial reaction to Dan's posting of Porsche's "technical bulletin'. They may have hoped it would serve 2 purposes...

1) obviously, that Porsche can deny warranty claims. but...it also may have been meant to have a secondary effect...

2) it gives the owners of "bad engined" cars the "cover" they need...underwhich to sell their cars. I mean, if Porsche has a technical bulletin out saying 400 miles to the qt. is "normal", then, how could a buyer "come back on" a seller who sells one of these cars...without full discloser? All a seller has to do is say..."oil comsuption well within Porsche guidelines. Good engine!!" It may be that they are trying to absolve sellers of these cars of any liablity. Which, in turn, would take even more pressure (Porsche hopes) off of them. That's just a thought I had....

I think Porsche knows they've got some issues that's not "ironed out" just yet. lol

DumeMan

I really love my 2009 991S. This is (believe it or not) my 8th new Porsche and the best ever. My ONLY complaint is after 6,500 miles I am still seeing one quart vanishing like clockwork every 600 miles and that is so inconsistent with all my previous 911's. My 2004 996 drank maybe a quart in 3-4,000 miles.

Is it the Variocam that puts oil in the upper chamber, or something else going on? I know the factory says this is OK, but the last car I owned that consumed a quart in 600 miles was my first car, a 1961 Morris Minor with 100,000 miles on the clock!

kosmo

can we PLEASE see a pic of your 991s?

GT3ZZZ

Just passed 4,000 miles in my 2010 997.2 GT3. It hasn't used a drop, still full.

Macster

Get the engine's oil/filter changed, then when you can after the engine is fully warmed up drive the car, hard.

I'm not saying to take the car out and drive it like you stole it but put some load on the engine. Not so much rpms but load.

At lower rpms with a larger throttle opening the combustion chambers will receive more air and more air means more fuel and more fuel means more pressure is generated. This pressure presses the rings against the cylinder walls and over time the rings will conform to the cylinder walls better and the rings will seal better. Oil consumption will go down.

Too light of driving can fail to help complete the ring seating and the engine is not yet fully broken in.

I sort of found the same thing in my 03 Turbo, that I bought with just 10K miles. The engine's oil consumption was higher than that of my 02 Boxster (with over (at that time) 200K miles) but I know engines vary in the amount of oil they consume.

My everyday driving consists of 60 mile (round trip) commute 5 (or more days per week) mainly at highway speeds.

But my pleasure driving has me take the car out on the open highway and usually half way across the country. My favorite route has me taking 58 highway from Bakersfield up to Tehachapi then down again over to Barstow. From there I haul the car 140 miles across I-40 up and down some mountains to Needles and from there on into AZ and then the nice 100+ run from Kingman to Flagstaff.

There are several sections of uphill grades that allow me to treat teh engine to some loading. Nothing real insane (too many bears, too much traffic) but I notice the engine on boost quite a bit going up the grades.

The result of a few of these is the engine's oil consumption dropped and now where it was using around 1 quart of oil per 5K miles (I change the oil every 5K miles) it uses around half that much.

Even at 10K miles the engine was not fully broken in. And lab and field testing has found that break in can be an ongoing process for 10K miles or even more.

So, if you want to see if you can improve (decrease) the engine's oil consumption take the car out every so often and put some load on the engine. Do not lug the engine but do drive it around on the fat part of its torque curve.

No guarantees but you might find oil consumption drops.

Sincerely,

Macster.

RED HORSE

My experience matches Macster's. My Sept 09 build 997.2 C2S Cab PDK used about a quart each 1,000 miles after break in that was done according to the book. I started accelerating hard, whenever I had an opportunity and now at 22,000 miles it uses about a quart or less each oil change which is every 6 months and about 6,000 miles. This isn't as good as my 997.1 or my 986, but is certainly acceptable to me.

chrcook

For what it's worth, I have a 09 c2s with 10k mi. It's a daily driver, completing most miles via a 30 mile commute which is 50/50 city / highway. I've burned about 1.75 qts over this time. It appears to not like being full, as after I add, it quickly returns to the 2/3 or 1/3 mark. Now, I let it stay at 1/3 for a while, then add about 1/3 qt when the mood hits. I've never seen the low oil light. Also, no soot, but since I drive it in the snow and salt of Michigan, tough to see.

Quadcammer

I realize this post is two years old, but lest anybody read it and think its ok, I must address it.

This is the biggest load of BS I've heard since the last ADias post I've read.

Yes, SOME oil consumption in a high performance engine is normal due to larger ring gaps, looser tolerances on various parts to deal with higher temps, etc. Also, the boxer engines do tend to puddle some oil on the bottom of the cylinders.

That said, 1 quart per 386 or 600 miles is absolute bull****. That is unacceptable for any car, much less a car world renowned for its robustness.

These cars are not race cars, and "how they are built" has nothing to do with it. Not only does this oil foul the cats, 02 sensors etc, it also is not good for emissions.

Furthermore, the issue is not the money, its the principle of paying upwards of $100k for what is supposed to be a quality product, and get a car that burns more oil than 500k mile kias.

Quadcammer

While there is some truth to this, the vast majority (i.e. probably 90%) ring seal is established in the first 30 minutes of run time.

Hence why if you want a strong running, low oil consuming engine, you load the engine as soon as you get it. Not beating on it, but driving it hard methodically.

Macster

Agree, but if an engine after way after that first 30 minutes is still showing signs of excessive oil consumption making some reasonable attempt to I hate to say it but making some reasonable attempt to force the rings to seat (some more?) might be called for.

As long as the oil is of the proper type, fresh, and the engine up to temperature, there's no harm.

And the benefit may be lower oil consumption and perhaps (though seat of the pants dyno may not detect it) a stronger running engine as well.

I would never advise one to beat on an engine. I don't mine. But I do use the engine -- once warmed up -- through all its various rpm and power/torque bands, yet avoiding lugging the engine or spending hours near/at redline. (I have managed to keep the Boxster at near V-max for miles on end and the engine appears to have suffered no ill effects from this since I did this maybe over 200K miles ago (IIRC I took the car out just before it was due to be booked in for an RMS and the RMS was done at around 26K miles and the engine now has over 238K miles on it). But save for that and a few, very few, other instances, my cars' engines don't see sustained operation near or at redline. They do see high rpms though, just not at redline. But I believe I have subjected my engines to proper break-in so the rings have seated as well as they can seat (and based on oil consumption I'd say they seated damn good) so this high rpm business is done with the engine broken in.)

Sincerely,

Macster.

Edgy01

I don't believe that the break in method is going to make any difference. We see many boxer engines of the watercooled variety now using an excess amount of oil. I have broken in other Porsche engines (all air cooled 911s) and never experienced the sort of excessive oil usage the 997S.1 has demonstrated. I'm not one to take it easy, either, on the rpms. I believe it's based upon a tolerance stack that occasionally manifests itself in the normal routine of engine building. Some of us luck out and get a great engine. And some of us get oil hogs. If the driver is the same across many samples (and consistent with their engine break in regiment) then the only other variable is mechanical.

Bonster

You guys have me confused, and somewhat scared. I have a 1995 993 Carrera -- yes, the last of the air-cooleds. While I was on the hunt for my first and likely last (only because I waited for the 'perfect' one to come along) Porsche, I learned that it is not atypical for an air-cooled engine of this genre to burn some oil. Ironically, mine burns hardly any! Can you believe that? This after autocrossing a few times, a couple times at the track, fun long-distance runs and back before I decided the truck was a better grocery-getter than my beloved 911.

I agree that a car, race-ready or not, should not be burning excessive amounts of oil. I realize that some cars inherently burn *some* oil, but give it a break. My question, I suppose, is are we talking about oil 'burning' in ALL Porsches (911s in particular), or just the older versions that used oil to cool the engine versus a radiator and its fluid?

These are mere questions, and I am always wanting to learn. I'm just trying to find out why one person is apparently always ticked that a car like ours would burn oil, versus the apparent factoid that older Porsches do in fact burn some. My Spec Miata racecar, when I was still running that series, would burn around a quart per race. That was normal in my world. Then again, I had an honest engine. I dunno. ???

Bonster

Another question . . . perhaps more of a statement . . . a friend of mind was looking at buying his first Porsche about a year ago. Well, he settled on a 996 with 'all the bells and whistles'. He went to check on the oil level and found it does not have a dipstick? WTF? That is the most insane thing I have ever heard. Is this true in all of the later 911s or just the 'all the bells and whistles' ones? He said he can only see the oil level via the computer / dashboard. I have yet to see inside his car, but this just sounds flat out SCARY to me.

So now you all have something to talk about. THANKS!!! for any insight!

FlatSix911

Total BS ...