DFI engines oil consumption
03-24-2010, 07:22 PM
#17
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Maybe this thread is in response to the thread about the guy who traded his Porsche for Vette due to excessive oil consumption. His case was definitely an exception.
03-25-2010, 06:38 AM
#18
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It is not the injection method that brings along the oil consumption guys, it is the high compression and higher operating temperatures.
However I rest my case, I am not trying to convince anybody just trying to give some peace of mind to those new DFI owners that are watching their cars eat oil like crazy by saying: this will normalise with time as you put some mileage to these new engines...
It saddens me somewhat to see users that are new to P cars (like the Vette guy on the other post) being so negative about their cars
However I rest my case, I am not trying to convince anybody just trying to give some peace of mind to those new DFI owners that are watching their cars eat oil like crazy by saying: this will normalise with time as you put some mileage to these new engines...
It saddens me somewhat to see users that are new to P cars (like the Vette guy on the other post) being so negative about their cars
03-25-2010, 07:03 AM
#19
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On one end of life we have natural born bus riders. Though they sometimes own cars, they really prefer never to worry about anything concerning their vehicle but the crick in their neck from leaning forward staring down the street to see if it's coming. Well, that and how to get other people's gum out of their clothes.
On this end of life, we have... Porsche owners. I like it here.
Even if I do refuse to change my own oil.
Gary
03-25-2010, 08:34 PM
#21
got my oil changed today at the local indy. The mechanic said the soot issue is due to the 'rich' mixture and he runs his Turbo 'rich', producing alot of soot. Now, for the oil consumption, he has no idea. I've mentioned before that I have gone through about 4 quarts in 7500 miles and now, we are going to monitor it until 10k. I'll keep you all posted!
03-26-2010, 07:33 AM
#22
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When are people topping up their oil? When the gauge is on the bottom marker or when its at the mid point with 2 blocks showing?
I ask this as I have used 1 litre (is that one quart in your money?) over 14,000 miles but most of that consumption happens very quickly i.e it goes from full (4 bars) down to 2 bars within a week or two, the gauge also will show full one day and 1/2 full the next and vice versa (I know its not 1/2 full as the gauge covers one litre but you get my point)
So you could be over filling if you are topping up all the time and the engine will or is designed to burn off the excess? I tend to look at my Oil pressure gauge as well as the oil level gauge...
I ask this as I have used 1 litre (is that one quart in your money?) over 14,000 miles but most of that consumption happens very quickly i.e it goes from full (4 bars) down to 2 bars within a week or two, the gauge also will show full one day and 1/2 full the next and vice versa (I know its not 1/2 full as the gauge covers one litre but you get my point)
So you could be over filling if you are topping up all the time and the engine will or is designed to burn off the excess? I tend to look at my Oil pressure gauge as well as the oil level gauge...
03-26-2010, 08:30 AM
#23
Race Director
Me too, Ross. And that's probably the best way to tie up this thread: be patient with your cars and learn to love them.
On one end of life we have natural born bus riders. Though they sometimes own cars, they really prefer never to worry about anything concerning their vehicle but the crick in their neck from leaning forward staring down the street to see if it's coming. Well, that and how to get other people's gum out of their clothes.
On this end of life, we have... Porsche owners. I like it here.
Even if I do refuse to change my own oil.
Gary
On one end of life we have natural born bus riders. Though they sometimes own cars, they really prefer never to worry about anything concerning their vehicle but the crick in their neck from leaning forward staring down the street to see if it's coming. Well, that and how to get other people's gum out of their clothes.
On this end of life, we have... Porsche owners. I like it here.
Even if I do refuse to change my own oil.
Gary
Loving a Porsche is one thing, but completely overlooking engineering flaws or poor production tolerances is just a way for Porsche to continue to be half assing stuff.
03-26-2010, 10:13 AM
#24
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oil consumption
I'll throw this into the mix.........
I had to bring my 997.1 to the dealer to have a new key programmed yesterday. While there, I mentioned I'd been reading alot of comments / complaints relative to high oil consumption on the 997.2's. He of course indicated that he didn't hear many complaints......then went on to say it would most likely be related to the method of 'break in' on the cars when new. He said if the cars were babied during break in that might promote higher oil useage. He thought cars that were driven hard during break in would relect lower oil consumption. Perhaps this explains why some cars don't seem to exhibit this issue while others do (I do also agree with the variation associated with manufacturing tolerances on some engines as I have been involved in mfg. and process process capability for many years)
Just wanted to pass this along. Maybe a survey of break in method / style would provide additional clues.
I had to bring my 997.1 to the dealer to have a new key programmed yesterday. While there, I mentioned I'd been reading alot of comments / complaints relative to high oil consumption on the 997.2's. He of course indicated that he didn't hear many complaints......then went on to say it would most likely be related to the method of 'break in' on the cars when new. He said if the cars were babied during break in that might promote higher oil useage. He thought cars that were driven hard during break in would relect lower oil consumption. Perhaps this explains why some cars don't seem to exhibit this issue while others do (I do also agree with the variation associated with manufacturing tolerances on some engines as I have been involved in mfg. and process process capability for many years)
Just wanted to pass this along. Maybe a survey of break in method / style would provide additional clues.
03-26-2010, 11:00 AM
#25
Is "using oil" and "burning oil" the same thing????
Are the engines blowing the oil past the rings or burning the oil in the cylinders????
I've got the black spots all over the garage floor and against the garage door...
Are the engines blowing the oil past the rings or burning the oil in the cylinders????
I've got the black spots all over the garage floor and against the garage door...
03-26-2010, 11:40 AM
#26
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.then went on to say it would most likely be related to the method of 'break in' on the cars when new. He said if the cars were babied during break in that might promote higher oil useage. He thought cars that were driven hard during break in would relect lower oil consumption.
If my car was using a litre of of oil every 600 miles I would be unhappy (but I've never had a car in 25 years that has used more than a litre between services)
03-26-2010, 12:08 PM
#27
What folks are not discussing in this thread is the fact that Porsche went to a different ( lower cost) cylinder surface treament process for the 2009/10 engines ( this has nothing to do with the fact that they have DI !). The different surface treatment is far more likely to affect the oil consumption rate.
03-26-2010, 12:24 PM
#28
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What folks are not discussing in this thread is the fact that Porsche went to a different ( lower cost) cylinder surface treament process for the 2009/10 engines ( this has nothing to do with the fact that they have DI !). The different surface treatment is far more likely to affect the oil consumption rate.
03-26-2010, 12:37 PM
#29
Race Director
The likeliest source is the very low tension rings used to reduce internal engine friction.
Other car makers that have gone this route have found -- or the car owners have found -- high oil consumption to be a problem.
Back in late 01 when I was looking at Corvettes the word was the engine was an oil burner. Some were so bad the owners managed to get the dealer/factory to re-ring the engines under warranty. Chevy released something to the effect the engines had low tension rings to reduce engine friction and high oil consumption was a possible side effect. Also, Chevy went on to say that how the car was driven also played a role.
Some owners were driving the Corvette like a small motorcycle taking revs up to redline then closed throttle coasting down and buzzing around town in low gears with engine way up its rpm band.
When Chevy pointed out this was sure to raise oil consumption some owners pointed out that Chevy sold the car as a sports car and they were using the car that way.
As I mentioned more than one owner got his engine re-ringed and some got new pistons and rings and few even got new engines.
While I don't believe that most Porsche owners of cars with DFI engines are treating their cars like the Corvette owners did that I mentioned above, the DFI engines do have low tension rings. And they'll use oil because of it, until the engine gets some miles on it. There will be a few that continue to use oil I'm sure there always are high oil consuming engines, even with high tension rings.
Sincerely,
Macster.
03-26-2010, 12:50 PM
#30
My twin turbo BMW 535 (DI) needed 1 quart at 7000 miles and one quart at about 30,000 miles. The oil is changed at about every 16,000 miles). It has cast iron cylinder liners and was broken in by the book. This car has "normal" oil consumption. My 2008 C2S has only about 3000 miles. It was broken in by the book, the level went down one bar at 500 miles and oanother bar at 1500 miles. I consider this a "normal" progression and I expect that my car will cosume oil at about 1 quart every 5000 or more miles. Now, I know some folks properly breakin their cars and still have high oil consumption rates and this is perhaps a "luck of the draw". But, the heavy oil consumption rates reported in these forums seems to point to something else. By the way my BMW has soot in the tailpipe and my 911 does have a little. This may have nothing to do with the oil but with the combustion process ( like Diesels).