DIY oil change; is it worth it?
Lab analysis involves many complex tests using sophisticated test equipment. There is no cost effective method that can be attached to your car to replicate these tests and accurately measure whether the oil is still doing it's job.
Don't waste your time unless you have a fleet of thousands of vehicles, in which case you can save hundreds of thousands of dollars per year by extending drain intervals through repetitive lab analysis of oil.
IMHO oil is so cheap that if you own ten cars or less use the following rule of thumb:.
Drain intervals twice per year, 5K miles or 250 approximate hours of engine operation - whichever comes first.
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Joined: Jan 2013
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From: atlanta
My Ride: 2005 545i Sport
It is amazing what an internal combusion engine can endure and still keep functioning:

That sludge built up over years and miles. Throughout its lifetime, it functioned at a level far below its spec's.
Have a shop use a borescope to check for sludge buildup in the cylinder head area if you're concerned about the possibility.

That sludge built up over years and miles. Throughout its lifetime, it functioned at a level far below its spec's.
Have a shop use a borescope to check for sludge buildup in the cylinder head area if you're concerned about the possibility.
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Joined: Dec 2012
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From: Montreal Quebec Canada
My Ride: 2005 545i, premium package, 6sp manual, cold package, navigation package.
Model Year: 2005
Engine: N62
Unfortunately there is none.
Lab analysis involves many complex tests using sophisticated test equipment. There is no cost effective method that can be attached to your car to replicate these tests and accurately measure whether the oil is still doing it's job.
Don't waste your time unless you have a fleet of thousands of vehicles, in which case you can save hundreds of thousands of dollars per year by extending drain intervals through repetitive lab analysis of oil.
IMHO oil is so cheap that if you own ten cars or less use the following rule of thumb:.
Drain intervals twice per year, 5K miles or 250 approximate hours of engine operation - whichever comes first.
Lab analysis involves many complex tests using sophisticated test equipment. There is no cost effective method that can be attached to your car to replicate these tests and accurately measure whether the oil is still doing it's job.
Don't waste your time unless you have a fleet of thousands of vehicles, in which case you can save hundreds of thousands of dollars per year by extending drain intervals through repetitive lab analysis of oil.
IMHO oil is so cheap that if you own ten cars or less use the following rule of thumb:.
Drain intervals twice per year, 5K miles or 250 approximate hours of engine operation - whichever comes first.
Your points on hours of running versus distance are right on. I did a quick calculation using your base of 250 hrs and I see that I have indeed fallen on about the same intervals as you, but I do manage to go about 20K kms in those 250 hrs.
Also your observation about the Cummins diesel is correct and is a technique we (industrial plants, in my case, petrochemical) use in running machinery continuously with now downtime to replace the lubricants. Our gas turbines which use synthetic lubricants exclusively, have a sidestream of oil removed continuously with a matching make up. Conductivity is one of the parameters we monitor, with, of course, periodic oil analysis.
Goos discussion.
Salut, Bob P.
New Members
Joined: Dec 2012
Posts: 571
Likes: 10
From: Montreal Quebec Canada
My Ride: 2005 545i, premium package, 6sp manual, cold package, navigation package.
Model Year: 2005
Engine: N62
Balbs, excellent information. I didn't know that the actual measurement used for 'condition' is capacitance, which is closely related to conductivity. It is quite common to use capacitance for fluid levels, however.
salut, Bob P.
salut, Bob P.
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Joined: Jan 2013
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From: atlanta
My Ride: 2005 545i Sport
You really need to get on top of checking that oil more often and probably changing it as well.
Put a date into your iphone to "check oil" each month. Do you know how to do this? If not, go to a full service station and have them check it for you.
Sounds like you're burning oil or going forever between oil changes.
Look at the photos of oil sludge buildup and then begin a program of changing that oil more often.
Let me suggest you purchase one of these and have your mechanic install it during the next oil change:
http://www.drainplugmagnets.com/ It can help to keep that oil cleaner for you between oil changes.
But it won't prevent carbon and varnish buildup which is probably occuring on your car.
BG has a professional cleaning flush that you might want to consider. Indy shops charge around $200 for it and you might be a prime candidate for it. First make sure that they run a borescope to see if you don't have large amounts of sludge built up. If so, sell the damn thing!
Last edited by paran; Feb 26, 2013 at 03:45 PM.
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Joined: Mar 2010
Posts: 3,099
Likes: 5
From: Los Angeles, CA
My Ride: BMW
Model Year: 2006
Ouch! Never good to see that "OIL" warning light. Never.
You really need to get on top of checking that oil more often and probably changing it as well.
Put a date into your iphone to "check oil" each month. Do you know how to do this? If not, go to a full service station and have them check it for you.
Sounds like you're burning oil or going forever between oil changes.
Look at the photos of oil sludge buildup and then begin a program of changing that oil more often.
Let me suggest you purchase one of these and have your mechanic install it during the next oil change:
MAGNETIC DRAIN PLUGS It can help to keep that oil cleaner for you between oil changes.
But it won't prevent carbon and varnish buildup which is probably occuring on your car.
BG has a professional cleaning flush that you might want to consider. Indy shops charge around $200 for it and you might be a prime candidate for it. First make sure that they run a borescope to see if you don't have large amounts of sludge built up. If so, sell the damn thing!
You really need to get on top of checking that oil more often and probably changing it as well.
Put a date into your iphone to "check oil" each month. Do you know how to do this? If not, go to a full service station and have them check it for you.
Sounds like you're burning oil or going forever between oil changes.
Look at the photos of oil sludge buildup and then begin a program of changing that oil more often.
Let me suggest you purchase one of these and have your mechanic install it during the next oil change:
MAGNETIC DRAIN PLUGS It can help to keep that oil cleaner for you between oil changes.
But it won't prevent carbon and varnish buildup which is probably occuring on your car.
BG has a professional cleaning flush that you might want to consider. Indy shops charge around $200 for it and you might be a prime candidate for it. First make sure that they run a borescope to see if you don't have large amounts of sludge built up. If so, sell the damn thing!
Just posted this on another thread...maybe not as bad as it seems...Maybe go for a long ride and then check the oil level again on the iDrive to see what the level is after the drive.
Ouch! Never good to see that "OIL" warning light. Never.
You really need to get on top of checking that oil more often and probably changing it as well.
Put a date into your iphone to "check oil" each month. Do you know how to do this? If not, go to a full service station and have them check it for you.
Sounds like you're burning oil or going forever between oil changes.
Look at the photos of oil sludge buildup and then begin a program of changing that oil more often.
Let me suggest you purchase one of these and have your mechanic install it during the next oil change:
MAGNETIC DRAIN PLUGS It can help to keep that oil cleaner for you between oil changes.
But it won't prevent carbon and varnish buildup which is probably occuring on your car.
BG has a professional cleaning flush that you might want to consider. Indy shops charge around $200 for it and you might be a prime candidate for it. First make sure that they run a borescope to see if you don't have large amounts of sludge built up. If so, sell the damn thing!
You really need to get on top of checking that oil more often and probably changing it as well.
Put a date into your iphone to "check oil" each month. Do you know how to do this? If not, go to a full service station and have them check it for you.
Sounds like you're burning oil or going forever between oil changes.
Look at the photos of oil sludge buildup and then begin a program of changing that oil more often.
Let me suggest you purchase one of these and have your mechanic install it during the next oil change:
MAGNETIC DRAIN PLUGS It can help to keep that oil cleaner for you between oil changes.
But it won't prevent carbon and varnish buildup which is probably occuring on your car.
BG has a professional cleaning flush that you might want to consider. Indy shops charge around $200 for it and you might be a prime candidate for it. First make sure that they run a borescope to see if you don't have large amounts of sludge built up. If so, sell the damn thing!
My typical oil changes will be more frequent now that I push the car harder. The problem is that my car goes from OK to "below minimum". I always have a spare qt in my trunk though so I just pull over and top it off.
Anyway, back to my original question. What exactly is minimum?


