Oil Consumption

Hello, a quart (1 liter) every 3,000km (2000miles).. is this normal for a 87,000km (60,000miles) engine? Driving is generally hard but not track-hard all the time.. There appears to be no smoke of any sort coming out of the exhausts, no oil droppings under the engine.. Confused.. Wael 99 996 C2 6sp

1 quart per 2k miles is better than most get. However, if your engine was better broken-in, it would be hardly using any oil.

Vilken - Can you define "better broken-in"?

Rings seated properly to allow for a better seal. Following the manufacturer's break-in instructions will not help the rings seat as well as they could. All of my P-cars have always consumed less than 0.5 quart in 5,000 miles or more. And, that's with plenty of hard driving.

Waz, if it was me I would be a bit concerned. My cars done a tad over 32k and I "never" have to put any oil in between services....even though I am pedantic and check the oil once a week. I don't track my car. But I also don't know if I drive it hard though. I just drive it like a porker is supposed to be driven.....I guess that's hard

Check for leaks? (RMS) Are you using mobil 0/40?, if yes.. Try 15/40. There may be blow by from insufficient seating. Sometimes owners fell compelled to change their oil early (before P recommendations) and motors don't get a chance to break in w slippery synthetic. You can drive your ***** off and it won't help if you change oil at 5K. The dirt & grime help the seating.

i always thought that oil consumption was greater during the initial period. i was also told that consumption will decrease around 10K miles. any truth to this? roy

It should, if you "allow" breakin. It's not automatic........ My wife had a 300C that was never broken in (4 years - 60,000mi)... Low rpms, fast oil changes. I had a 300C at the same time & it was nite & day between both.

No defo not RMS. Waz said a 1/4 litre every 2k miles. If the RMS caused that much oil loss thru your crancshaft seal you seriously are in big trouble. He would notice this in both engine oil pressure and the clutch would be well hosed. RMS leaks generally are very small leaks. a few drops a day max. Typically two or three drops a week is symptoms of RMS! Anyway, Waz said there was no oil drops under the engine. Waz, have you checked the obvious like your cooling fluid. Any oil or foam in there indicates head problems. But then that much oil loss in to the water would cause serious pressure and cooling problems too. What about heavy black or white deposits in the exhaust. Also, your in Dubai, maybe with the heat there you can't see smoke coming out the exhaust. Like I said, I would have it checked out IMHO.

Just to make sure I understand, following the maufacturers break-in instructions will not help the rings seat as well as they could? How would I break the car in so that the rings would seat well?

Here's an email I sent to another poster earlier today: " Yes. The key to have properly seated (in final position) ring for the best possible seal between piston and cylinder walls, is to vary the engine revs as quickly as possible and as often as possible. This process will become even more effective if you do not restrict the rpm's as per the owner's manual. I believe that's 4000, right? When I get a new car, I always drive it as if it is already completely broken-in without intentionally hitting redline or the rev limiter. None of my previous 911's ever burned more than 0.5 quart in 5000 miles of driving. My new GT3 now has 1400 miles and not one drop of oil is needed. "

I lived by Viken's rule of break in on a decent list of sports cars I have purchased new and I have never had any problems with either performance or excessive oil use. I usually do alot of rapid in gear accelleration/decelleration back to back in 2nd, 3rd or 4th gear depending on if I am on high way or in a 35 mile per zone.

While I respect Viken's opinion, consider this: Your car is many systems - some with friction bearing. Manufacturers look at the entire car for breakin recommendations. They limit the high rpm (but recommend variances) for reasons other than the engine. An example is the suspension (shocks) and valve guides. Your motor is one of the componants. You can accelerate motor breakin with higher rpms (lower gear selection) and many off throttle procedures (it allows oil w/o gas in the cylinders) & brings oil to the head. Changing synthetic oil too early in motors on new cars retards breakin. VW puts an additive in the synthetic oil in the Treg to increase friction and as a result recommends an early change (5K I think). They used to use dino cutting oil initially in cars and recommend 1000K changes. Just my .02

Thank you for the replies, I am quite interested in what Scouser had to say... Surely it is not a RMS leak.. I have experienced an RMS leak in my previous carrera: you do get droppings of oil on the floor (from the joint engine-gear) and the clutch eventually slips while causing a big cloud of smoke at every throttle slippage.. But scouser, u noted two important things: 1- the car has had a previous cylinder-head change (one of them only) due to a previous overheat. The repair is still under guarantee 2- there is oil gathering on the water reservoir cap. And the water is always ponded with a thin oil film. I am suspecting since oil is heavier than water, that the major oil leak is gathering somewhere in the lower cooling system? is it possible? 3- the temperature of the water is around 12oclock position at high speeds and 1oclcok position in heavy traffic I am suspecting either 1) the oil heat exchanger to be mixing oil with water 2) the cylinder head repair is still leaking droplets in the water system I will go again and present the case to the repair shop... Waz

By the way, the oil pressure is jsut about right with a reading of '5' above 4k rpm's and about '1.5' to '2' on idle, both when the engine is hot. waz

i just vent too ze repar shope.. the ownerr vaz in austria for ze holidayz and he sait ze oil cunsumptioun ist ein normale.. Vone liter per Vone soussand kilometer fur ein boxer engeene.. i told him i doubt this is right.. so i'll keep a monitor. We finally agreed I'd drop the car for a day for them to check out things.. Will keep posting.. Afudazein Vaz

Interesting. But in item 2, the oil you say is a thin film. This is probably not oil but coolant "scum" if you don't mind the word. If you had a blown head gasket you can expect any (or all) of the following: oil (white/grey/brown foam) in the coolant header. It would be quite bad and not just a film. If oil is in your coolant and its as bad as 1/4 litre (heaven forbid) the car would seriously overheat. And in Dubai it would overheat quickly. That ammount of oil in the water and oil presure would be obviously bad. water in your oil. Again, frothy foam (white/brown) in the oil fill cap. You might also see dirty water coming out your exhaust. Oil in your water is normally the first sign of head gasket blown. One thing you haven't told us Waz is what type of oil you use. If your using 00/40 try moving to a thicker oil 15/40 or even 20/40. Your car has quite high mileage and the valves may be blowing back the oil. Extar valve wear may have been caused by previous overheating prior to the head being redone. Does the car idle OK. hot and cold? What sort of fuel consumption you getting? When the car is hot, cat you smell any oil? Have someone drive behind you (if they can keep up ) as you run through the revs and see if they can see clouds of smoke at all. In item 3: what you have here is normal. 12oclock when engien is at normal temp. A little higher in heavy traffic or hot temps.

i broke in my previous 911's the "normal" way and use 1 qt about 2000-2500 miles. i used viken's method on gt3 and drove it like no tomorrow since 250 miles. no oil needed with 3800 miles on the clock.

Scouser, here goes pics of the water tank cap.. this much foam (?)accumulates as much as i try to wipe them off, the same amount comes back.. As for inside of the water tank, i hope the picture is clear.. you can notice a film only of oil. The same foam accumulates on the sides of the reservoir. And mind you, the coolant level does not reduce i rarely add water to the reservoir. To answer your questions: - there is no water in the engine oil. When i remove the dipstick, it is only oil with no foam accumulation. The engine oil fill cap is dry of anything. The engine bay is also very dry of oil, as well as the joints of the engine itself (under, on the sides, on the gear/engine joint).. - there is no smoke that comes out of the exhausts, not even a puff at all rpm's - car idle is perfect at all temperatures, no jerking no osciliations. power is top at all speeds and rpm's - i run a full tank of fuel with 350km on average - when the car is hot, i dont smell oil, just exhaust smokes (CO2) when i open the sunroof mostly That's about all i can add! Waz 99 C2 6sp

And btw, the repair shop manager said that due to the previous cylinder head gasket blowing up and the follow-up repair of changing the whole cylinder head itself with the gaskets... that there is a lot of oil that went into the water system, and this is what is appearing on the oil cap now: old oil residue.. not new oil.. Beats me... Waz

I would tend to agree with him..... I think.....although that cap does look like head problems if you didn;t know it had been done before. The coolant is supposed to be a once only lifetime fill. That is you don't have to fill it/top it up (except of course if it had to be drained for repair). Also I have a feeling the dealer drains it and fills it at major service intervals but not sure. Saying that, if the coolant had not been filled since the head repair then it is very possible that that gunk you are seeing is the result of the oil that contaminated the system when the gasket failed. I think you just have an engine that's hungry for oil. Probably because it was never burned in correctly. I dunno. As I said I don't use any at all. Strange. But you have good pressure, idles fine, temps fine, power's fine. Sounds like a good engine to me. So here's an idea just as an insurance (and peace of mind): Go back to the dealer, say that you would be satisfied so long as you have it "in writing" that if the engine goes belly-up, they will put it right gratis.

Thanks Scouser, I guess i'll keep a watch then.. The repair invoice and receipt of the head is enough to insure the job for a One year warantee for what they repaired.. So I guess I'll just take the car for a general checkup.. enjoy the car to the extremes.. Waz 996 99 C2

Leaving contaminated coolant (with oil) after a head gasket change is unacceptable service or more appropriately - Bull****. IMHO.

No matter how you flush the engine after a head gasket failure, you almost always get a bit of residue oil left in. What Waz is seeing is only residue. Waz, clean the cap, scrape off the oily scum from the top of the resevior coolant. Keep an eye on it. My bet is that you won't see it again. At least if you do this a few times, it will gradually lessen. If it gets worse then you know the story. Go drive that beast

Torags the engine's been flushed and as scouser is saying, it's alway residue that comes out.. i'll keep a watch and keep posting.. now lemme go drive the beast! Waz