"Your valve guides are worn"
11-02-2006, 07:39 PM
#16
Race Director
Originally Posted by Edward
The Porsche rec on oil consumption (as Steve W. mentioned) is 1qt/800 miles. Any consumption that's better than that is just not worth worrying about --assuming the car is running well, of course. Edited by BW
Edward
Edward
Personally, I would start arranging a rebuild at 1 qt. per 800 - 1000 mi. myself.
11-02-2006, 07:58 PM
#17
Weathergirl
Rennlist Member
Rennlist Member
Porsche's official figures are "up to 1.5L per 1000 km"
11-02-2006, 07:59 PM
#18
Three Wheelin'
Thread Starter
Why not just go with say 1.58 qt. every 1000 mi before you schedule a re-build Bill? It seems to me that if the cars had differing tolerances when built you potentially would do a rebuild right out of the box although most people here aren't seeing very high consumption levels from what I gather. I suspect there are a number of cars burning a quart every 1000 to 1500 and it seems like its fairly normal.
I'm actually glad to see that info. because I thought the factory's low end of the range for mileage vs. consumption parameters was about 1qt. every 1000mi. That sure seems like alot of oil consumption for only 621 mi. Whats that, roughly 3/4 of a quart of oil for every tankfull of gas? Thats a scary thought!
I burn around 1 qt every 1000 mi on average and have one bank of cylinders reporting blockage. Its been that way since I've owned the car over 25,000 miles of use.
I just figured once my clutch fails me then it would be time to go to town and do guides and everything else at the same time.
Does my owner's manual show the oil consumption specs or does someone actually have a scanned copy, PDF etc.? Nothing like conflicting information or even worse, relying on incorrect information you get on a web-forum without actual evidence. (although I trust most of what is written here if enough people write the same thing!
)
I'm actually glad to see that info. because I thought the factory's low end of the range for mileage vs. consumption parameters was about 1qt. every 1000mi. That sure seems like alot of oil consumption for only 621 mi. Whats that, roughly 3/4 of a quart of oil for every tankfull of gas? Thats a scary thought!
I burn around 1 qt every 1000 mi on average and have one bank of cylinders reporting blockage. Its been that way since I've owned the car over 25,000 miles of use.
I just figured once my clutch fails me then it would be time to go to town and do guides and everything else at the same time.
Does my owner's manual show the oil consumption specs or does someone actually have a scanned copy, PDF etc.? Nothing like conflicting information or even worse, relying on incorrect information you get on a web-forum without actual evidence. (although I trust most of what is written here if enough people write the same thing!
)
11-02-2006, 08:16 PM
#19
Drifting
Join Date: Jul 2006
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Have 13K miles on a 97. No valve noise or smoke doing the 6k to 2k coast and then floor it. SAI ports are clear, no oil leaks.
But I burn 1 qt every 900 miles.
But I burn 1 qt every 900 miles.
11-02-2006, 09:40 PM
#20
Originally Posted by DaveM993
Have 13K miles on a 97. No valve noise or smoke doing the 6k to 2k coast and then floor it. SAI ports are clear, no oil leaks.
But I burn 1 qt every 900 miles.
But I burn 1 qt every 900 miles.
11-02-2006, 09:52 PM
#21
Race Director
Originally Posted by RallyJon
I'm curious, since I've seen so many different rates of consumption listed as official, is that number for 993s in particular? What's the source?
As for why I'd start looking to repair before 1.5L @ 621 mi. I just think that's far too much oil consumption for my taste, but I'm NOT a tech guru, I wouldn't even consider myself a mechanic, so don't take a lot of stock in my opinion on this subject.
On my '88 I changed oil at 2,500 mi. and went through much less than a qt. between changes. As for the 993, I just changed the oil so I don't have consumption figure on that yet but from what I've seen so far it too will be pretty low.
11-02-2006, 10:04 PM
#22
Race Director
Originally Posted by DaveM993
Have 13K miles on a 97. No valve noise or smoke doing the 6k to 2k coast and then floor it. SAI ports are clear, no oil leaks.
But I burn 1 qt every 900 miles.
But I burn 1 qt every 900 miles.
11-02-2006, 10:27 PM
#23
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Originally Posted by 993BillW
I'm curious, are you trying to keep the oil level at the top of the fill mark on the dipstick? My '88 would burn it down to the mid point on the stick and then stop. If I tried to keep it at the full mark I would be adding oil every gas fill up, but it stoped at about the halfway point on the stick. Being a semi-dry sump engine I don't quite understand it but that's the way my '88 was.
11-02-2006, 10:45 PM
#25
Originally Posted by 993BillW
If I tried to keep it at the full mark I would be adding oil every gas fill up, but it stoped at about the halfway point on the stick. Being a semi-dry sump engine I don't quite understand it but that's the way my '88 was.
11-03-2006, 09:11 AM
#27
Rennlist Member
I just figured once my clutch fails me then it would be time to go to town and do guides and everything else at the same time.
Yep...that's what I did. Had SAI problems on one side...but clutch was slipping bad. Did the top end rebuild while the motor was on the floor for the LW flywheel and new clutch. FYI...CEL only referenced one side of the SAI, which was very plugged, but other side was pretty bad too. Done at 49K with normal oil usage (whatever that is-can't determine from this thread) so left the guides alone.
Yep...that's what I did. Had SAI problems on one side...but clutch was slipping bad. Did the top end rebuild while the motor was on the floor for the LW flywheel and new clutch. FYI...CEL only referenced one side of the SAI, which was very plugged, but other side was pretty bad too. Done at 49K with normal oil usage (whatever that is-can't determine from this thread) so left the guides alone.
11-03-2006, 11:29 AM
#28
Race Director
Originally Posted by 993BillW
For the 993 it's in my copy of the (993) Workshop Manual, Vol. 1, Tech. Data Sect. 0 pg 4. I'm almost positive you'll also find it in the owners man. but I don't have that in front of me. I think that was the same figure on my '88 911 too, but again I'm not positive.
11-03-2006, 01:05 PM
#29
Three Wheelin'
Thread Starter
Thanks Bill, that is good information. Its curious why some cars that have oil consumption in the 1qt per 1000mi range don't experience SAI blockage or maybe they just haven't YET.
I've read how sometimes not using a car can cause moisture to get into the oil thereby making the level appear higher than it actually is when checked. But I also have heard the level would drop once the car was run a bit. I guess I wonder how often the garage queen owners here are checking the level and whether very limited use would be enough to burn off all the moisture in the system? (assuming this is not a myth)
I'm definately burning oil within spec and I definately have both worn guides and SAI blockage on one side. There's no doubt that this will have to be addressed at my first opportunity when the engine is dropped but at this point I'm not planning on messing with anything until clutch time unless I have a rapid drop off in miles per quart or I can't pass smog. I was very, very lucky and the Porsche service in my area passed my car even though I had a CEL for SAI. They said the car was burning clean and that because its a known problem with the SAI passages and not a real dirty car issue they give it the AOK and will deal with the referee for me if necessary. What they meant about that last part I have no idea but you can imagine my elation not having to drop tons of dollars on clearing the ports for the next two years. I figure it will be done the right way by the time the car needs to be smogged in 2 yrs instead of throwing good money away on what may only be a temporary fix.
So in the end its major oil consumption way below spec that could result in a problem and that would be the reason to go after the guides. Other than that I would say its not broken so no reason to fix it.
I've read how sometimes not using a car can cause moisture to get into the oil thereby making the level appear higher than it actually is when checked. But I also have heard the level would drop once the car was run a bit. I guess I wonder how often the garage queen owners here are checking the level and whether very limited use would be enough to burn off all the moisture in the system? (assuming this is not a myth)
I'm definately burning oil within spec and I definately have both worn guides and SAI blockage on one side. There's no doubt that this will have to be addressed at my first opportunity when the engine is dropped but at this point I'm not planning on messing with anything until clutch time unless I have a rapid drop off in miles per quart or I can't pass smog. I was very, very lucky and the Porsche service in my area passed my car even though I had a CEL for SAI. They said the car was burning clean and that because its a known problem with the SAI passages and not a real dirty car issue they give it the AOK and will deal with the referee for me if necessary. What they meant about that last part I have no idea but you can imagine my elation not having to drop tons of dollars on clearing the ports for the next two years. I figure it will be done the right way by the time the car needs to be smogged in 2 yrs instead of throwing good money away on what may only be a temporary fix.
So in the end its major oil consumption way below spec that could result in a problem and that would be the reason to go after the guides. Other than that I would say its not broken so no reason to fix it.
11-03-2006, 01:25 PM
#30
Race Director
Originally Posted by 2ndof2
edited..
I've read how sometimes not using a car can cause moisture to get into the oil thereby making the level appear higher than it actually is when checked. But I also have heard the level would drop once the car was run a bit. I guess I wonder how often the garage queen owners here are checking the level and whether very limited use would be enough to burn off all the moisture in the system? (assuming this is not a myth)
I've read how sometimes not using a car can cause moisture to get into the oil thereby making the level appear higher than it actually is when checked. But I also have heard the level would drop once the car was run a bit. I guess I wonder how often the garage queen owners here are checking the level and whether very limited use would be enough to burn off all the moisture in the system? (assuming this is not a myth)
Originally Posted by 2ndof2
edited.. I'm definately burning oil within spec and I definately have both worn guides and SAI blockage on one side. There's no doubt that this will have to be addressed at my first opportunity when the engine is dropped but at this point I'm not planning on messing with anything until clutch time unless I have a rapid drop off in miles per quart or I can't pass smog. I was very, very lucky and the Porsche service in my area passed my car even though I had a CEL for SAI. They said the car was burning clean and that because its a known problem with the SAI passages and not a real dirty car issue they give it the AOK and will deal with the referee for me if necessary. What they meant about that last part I have no idea but you can imagine my elation not having to drop tons of dollars on clearing the ports for the next two years. I figure it will be done the right way by the time the car needs to be smogged in 2 yrs instead of throwing good money away on what may only be a temporary fix.
So in the end its major oil consumption way below spec that could result in a problem and that would be the reason to go after the guides. Other than that I would say its not broken so no reason to fix it.
So in the end its major oil consumption way below spec that could result in a problem and that would be the reason to go after the guides. Other than that I would say its not broken so no reason to fix it.