Crown
Board: Porsche - 911 - 996
Language: English
Region: Worldwide
Close
CloseForum - Thread
Re: I called the dealer today about my low oil warning...
Quote:
aml161 said:
The Service Mgr said that it's normal for a 911 (mine's an 03) to "burn" through a quart of oil every 2000 miles or so.
What do you think about this? Is it true? I've owned several p-cars before and never experienced this.
Maybe he should have rephrased that to: "it's not abnormal for a 911 to burn a quart of oil every 2000 miles or so", which would be a little more true.
I've had cars which used so little oil I couldn't put a figure on it, and others where I preferred not to think about the subject of oil consumption, but even the "drinkers" seemed to lose their appetite for the stuff with increasing mileage.
Sep 9, 2005 5:20:33 PM
- TT Surgeon
- Senior
-
- Loc: Long Island, NY , United States
- Posts: 783, Gallery
- Registered on: Dec 28, 2004
- Reply to: aml161
Sep 9, 2005 7:53:48 PM
- Grant
- Rennteam VIP
-
- Loc: Denver, CO , United States
- Posts: 12588, Gallery
- Registered on: Aug 21, 2002
- Reply to: TT Surgeon
Re: I called the dealer today about my low oil warning...
Quote:
Grant said:
The factory max spec for oil consumption is 1qt/1000km or 620 miles. They won't say it's broken until it uses that much or more...
Grant, Fritz or anyone,
Is there any correlation (holding all else constant) between oil-burning rate and engine performance/longevity? Any difference between a NA and turbo 911? My 996TSCab used about a quart of oil in the first 1,000 miles, but, if the dashboard readout is to be believed, hasn't burned much since-now at about 2,400 miles. I followed my dealer's mechanic's advice and broke in the engine revving up to near (but below) redline-not more than 6,000rpm's-methodically (not rapidly), and have been driving rather spiritedly since then,
and the car seems VERY FAST! 
It's gotta be good for 0-60mph under 4 seconds, and, if the digital speedo readout is to be believed, I can get the car to 75-80mph in second gear at about 5,500-6,500rpm's. 
Of course, the speedo could be off by, what, 10% or more? 
Presumably, the more friction/heat generated increases the oil-burning rate, and I would think that an engine that operates with greater friction produces less HP and torque since energy is used to overcome that friction and to be released as heat. Or is there another factor in oil consumption (besides leaks
) that doesn't impact HP production?
Re: I called the dealer today about my low oil warning...
Quote:
Al Pettee said:Quote:
Grant said:
The factory max spec for oil consumption is 1qt/1000km or 620 miles. They won't say it's broken until it uses that much or more...
Grant, Fritz or anyone,
Is there any correlation (holding all else constant) between oil-burning rate and engine performance/longevity? Any difference between a NA and turbo 911? My 996TSCab used about a quart of oil in the first 1,000 miles, but, if the dashboard readout is to be believed, hasn't burned much since-now at about 2,400 miles. I followed my dealer's mechanic's advice and broke in the engine revving up to near (but below) redline-not more than 6,000rpm's-methodically (not rapidly), and have been driving rather spiritedly since then,
Presumably, the more friction/heat generated increases the oil-burning rate, and I would think that an engine that operates with greater friction produces less HP and torque since energy is used to overcome that friction and to be released as heat. Or is there another factor in oil consumption (besides leaks
Al, first a disclaimer: I make no claims to personal specialist knowledge or professional expertise in this subject, so anything I say is just my personal interpretation of basic engineering text-book learning, peripheral contact with people directly involved with such matters,general reading, hearsay, and personal observation of own cars!
Many factors can influence the rate of engine oil consumption: matching of piston and cylinder dimensions to each other; tolerances of bores, pistons, piston rings; design, material and heat-tratment of piston rings; surface finish of bores, pistons, rings; components broken-in or not broken-in; effectiveness of shaft sealing of intake/outlet valves; specific engine operating conditions - and any random combination of any of these and maybe a dozen other factors.
So a high oil consumption problem does not necessarily have a simple, obvious, reliably effective fix. Discounting very high mileage engines with bores so worn that large volumes of combustion gases blow by the piston rings, I don't think there are hard and fast rules saying that high oil consumption engines necessarily have less power than low consumption engines. Same applies to NA versus turbo engines. Same applies to engine longevity.
All internal combustion engines rely on "controlled leaks" of gases or oils through clearances to allow for relative displacement of moving parts. I suspect that these leaks play a larger part in the rate of oil consumption than does the additional heat generated by abnormally high friction.
Re: I called the dealer today about my low oil warning...
In addition to Fritz' analysis, I would also suspect that how one drives may have an impact
- Short trips where the engine doesn't properly warm up may cause slight differences in the metal expansion and clearances
- Lots of constant high speed driving, could also cause differences in clearance
- When an opposed cylinder, flat design engine sits a long time more oil collects at the bottom of the cylinder and then is burned up when started
Just some theories.....
- Short trips where the engine doesn't properly warm up may cause slight differences in the metal expansion and clearances
- Lots of constant high speed driving, could also cause differences in clearance
- When an opposed cylinder, flat design engine sits a long time more oil collects at the bottom of the cylinder and then is burned up when started
Just some theories.....
I bet it was all that Boxstoberfesting. 
Sep 19, 2005 2:13:03 PM
- C70Pete
- Newbie
-
- Loc: toronto, canada
- Posts: 3, Gallery
- Registered on: May 22, 2005
- Reply to: MattTheCarNut
Forum
About Rennteam | Help | Terms of use | Privacy Policy | Support | Contact | Imprint | Archive
Powered by
Community
and
