Change oil after 500 miles to get metal shaving out
12-05-2009, 03:50 PM
#16
Race Director
I've read in many places that changing the oil on a new porsche is recommended at around 2000miles, but track buddies of mine insist that its necessary at around 500 miles to change the oil in order to get the metal shavings that fell off a new engine out of the system. Anyone agree or care to comment?
This can't be a bad thing.
New engines shed alot of metal debris. Your track buddies are right, in a sense. There may be metal shavings left in the engine, but these aren't a problem. They end up in sump or after going through pump in filter housing. These metal shavings take this route first time engine started or shortly thereafter.
What is a bigger concern is the normal shedding of metal debris as the engine runs and breaks in.
This shedding is expected as any new machined cast or forged surface has a surface will shed material. As a machinist I ran my hands over many a freshly machined suface, cast surface or a forged surface and it was very evident one could loosen material just with a hand. Even if the surface is not a bearing surface the action of the oil running over the surface and in areas with more oil action the violence of the oil will "blast" the looser particles from the various surfaces and the particles end up in the oil.
At the bearing surfaces, mainly the piston/ring/cylinder interfaces but also at the camlobe and valve followers engine break in is wear taking place and this also puts metal debris in the oil. These are caught by the filter which will over time lose abilty to flow as much oil as it did new and clean.
As the filter becomes clogged, oil pressure increases as the filter acts to block oil flow. There is a pressure relief valve in the oil pump that prevents overpressure but from the engine's point of view having a good oil flow at all times best.
Also, new engines typically experience a lot of blow by. This too natural. But this accelerates the build up of combustion by products in the oil. Two of particular concern are water and gas. Both work to reduce the viscosity of the oil and compromise its abiity to provide protection against metal to metal contact. New engines have higher levels of internal friction and these areas of higher friction of course operate at higher temperatures. One wants an oil that can properly handle these temperatures, and oil burdened with a goodly amount of water and and unburned gasoline ain't that oil.
Change the oil early. The cost is relatively small over the lifetime of the vehicle and you will at least have peace of mind knowing you did the best thing you could do to ensure the engine has a long and trouble free life.
If you don't want to do an early oil change then at least consider doing one at end of break in. This way when you begin to up max. revs and subject engine to higher loads and higher operating temperatures the engine is operating with fresh and clean oil.
Or just do nothing but follow the scheduled oil/filter service interval. It is your car.
I've always treated new engines to an early oil/filter service. Used to be quite common, but automakers are moving away from any maintenance as much as possible. Engine basics have not changed. Oil has not changed, that much. The factors that see a rapid build up of metal debris in oil are present, have been present in engines since day one and are present today and will be present as long as internal combustion engines are with us.
Mike Miller in BIMMER comments frequently on BMW's "global war on maintenance" which he believes is to the deteriment of engine and drivetrain longevity. Rightly so. And he is to be commended in his low opinion of BMW's policy. I am not in same leaque as Mike Miller but I have a low opinion of Porsche's maintenance policy though at some level I can understand what drives it.
The desire is to soften the blow of ever more expensive cars by seeking to ensure the new owner isn't faced with the cost, small though it may be, of an early preventative oil/filter service.
Sincerely,
Macster.
12-05-2009, 04:14 PM
#17
Burning Brakes
That's for sure. There has been an awful lot of discussion and opinion on the benefits of performing oil changes sooner and/or more frequently than the manufacturer's recommendation. I would really like to see an independent controlled study done to see if there is any basis for this. Until then I would rather err on the side of changing my oil too often rather than not enough.
12-05-2009, 04:29 PM
#18
Banned
Ad nauseum. At least once a month.
The suggestion is to change the filter only, if you're the least bit concerned. That's what I would do. The oil should still be good. No need to throw good oil away.
The suggestion is to change the filter only, if you're the least bit concerned. That's what I would do. The oil should still be good. No need to throw good oil away.
It's a known and understood fact that rotary components of engines, though precisely machined, are nevertheless manufactured within acceptable plus or minus tolerances. During the wear-in process these components are worn down naturally until they find their true centers of rotation with respect to their mating components. Once they do, the efficiency goes up, horsepower goes up, and break-in is effectively over.
The wear-in process is effectively the final machining stage where parts are honed to perfection. Think about that for a minute. And the byproducts of this machining process are the fine metal particles that can be seen in the oil. I for one provided empirical proof of this.
Now, the question you must ask yourselves is do you want to continue driving your car, knowing these metallic particles are floating in your oil and coming between engine components, and wait until 20,000 miles for your first oil change to dump these metallic particles out?
Some of you may be quick to point out that it's the job of the filter to trap these harmful metallic particles and thus prevent them from harming the engine. Well, what if the filter in your car happened to be a defective one that slipped through quality control? It could happen. Are you willing to risk the life of your engine on the integrity of a paper filter? Do you feel lucky?
Ideally, an engine would run best in an open lubrication system. Fresh oil from an endless source would be pumped through the engine (after preheat of course) and dumped out along with the products of combustion and other debris. But to make an engine practical it must operate in a closed lubrication system. And so petroleum engineers have continuously improved oils so that they can last as long as they can before needing to be dumped out.
The "ideal" engine will run forever, as there will always be a layer of fresh oil between parts and no parts will ever come in contact with each other and no engine wear will result. The life of the practical engine is largely dependent on the quality of the oil - as any oil manufacturer will tell you.
Changing the oil frequently is thus beneficial to the engine. Changing it not often enough will cost you much more than the oil changes would have.
The wear-in process is effectively the final machining stage where parts are honed to perfection. Think about that for a minute. And the byproducts of this machining process are the fine metal particles that can be seen in the oil. I for one provided empirical proof of this.
Now, the question you must ask yourselves is do you want to continue driving your car, knowing these metallic particles are floating in your oil and coming between engine components, and wait until 20,000 miles for your first oil change to dump these metallic particles out?
Some of you may be quick to point out that it's the job of the filter to trap these harmful metallic particles and thus prevent them from harming the engine. Well, what if the filter in your car happened to be a defective one that slipped through quality control? It could happen. Are you willing to risk the life of your engine on the integrity of a paper filter? Do you feel lucky?
Ideally, an engine would run best in an open lubrication system. Fresh oil from an endless source would be pumped through the engine (after preheat of course) and dumped out along with the products of combustion and other debris. But to make an engine practical it must operate in a closed lubrication system. And so petroleum engineers have continuously improved oils so that they can last as long as they can before needing to be dumped out.
The "ideal" engine will run forever, as there will always be a layer of fresh oil between parts and no parts will ever come in contact with each other and no engine wear will result. The life of the practical engine is largely dependent on the quality of the oil - as any oil manufacturer will tell you.
Changing the oil frequently is thus beneficial to the engine. Changing it not often enough will cost you much more than the oil changes would have.
12-05-2009, 09:27 PM
#19
Racer
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( Another reason why I would never buy a used car. Lol)
How do you know the oil is still "good" ?
Dirt and loss of viscosity are only one aspect .
How good is your oil "filter" at removing contamination from combustion byproducts , fuel ,acids, moisture etc. ?
( that's the stuff which not only attacks metal , but also your seals, gaskets etc )
Is that not the main reason why manufacturers recommend changing the oil at least once a year , regardless of how many miles are driven ?
12-05-2009, 10:16 PM
#20
Banned
Yeah, not having a dipstick makes it kinda tough to judge the condition of the oil, not being to smell it or see it.
But after only 1000 miles, I think it's fair to say the oil is still good, if you're just thinking of replacing the filter and keeping the oil until the next scheduled oil change.
I really think PAG has done customers a major disservice by not providing a means of sampling the oil in between oil changes.
But after only 1000 miles, I think it's fair to say the oil is still good, if you're just thinking of replacing the filter and keeping the oil until the next scheduled oil change.
I really think PAG has done customers a major disservice by not providing a means of sampling the oil in between oil changes.
12-06-2009, 03:18 AM
#22
12-06-2009, 03:56 AM
#23
Nordschleife Master
To change oil at 500 miles is perhaps too soon but changing it at 20k miles is nuts. It's your car so do as you please, however when you sell it, a buyer should check maintenance intervals and may walk away. I would.
12-06-2009, 04:05 AM
#24
Nordschleife Master
my 997.1 ran fine, and was maintained along with the demands by PCNA as well. its not like they are BMW and paying for the service so they have no ulterior motive in saying to change oil at 20k... bmw on the other hand does it because they pay for all scheduled mait and dont wanna have the costs rack up., LOL
12-06-2009, 04:08 AM
#25
Nordschleife Master
they would walk away, based on the fact the oil was changed when PORSCHE, the manufacturer of thousands and thousands of 911's said to do?
my 997.1 ran fine, and was maintained along with the demands by PCNA as well. its not like they are BMW and paying for the service so they have no ulterior motive in saying to change oil at 20k... bmw on the other hand does it because they pay for all scheduled mait and dont wanna have the costs rack up., LOL
my 997.1 ran fine, and was maintained along with the demands by PCNA as well. its not like they are BMW and paying for the service so they have no ulterior motive in saying to change oil at 20k... bmw on the other hand does it because they pay for all scheduled mait and dont wanna have the costs rack up., LOL
