Diesel Place banner

1 - 20 of 23 Posts

·
Registered
Joined
·
276 Posts
Discussion Starter #1
Hoot posted a link to this GM article on the "GM Oil Life" system:


http://service.gm.com/techlink/html_en/pdf/200111-en.pdf#dst07


IF this is GM's "official" position on oil life, then why do they tell you to change the oil on a regular basis in the owner's manual? According to this article, the oil life monitor can evaluate all driving conditions and accomodate accordingly, thus shortening or lengthening the time the time between changes.


It CLEARLY states in the article that the "myth" about changing your oil every 3000 miles is perpetrated by "oil changing" facilities. Well, I got news for GM, my dealer does all of my oil changes, and my DEALER recommended interval is always 3500 miles.


As a point of reference, my "CHANGE OIL" message has never come on in the DIC.


Is it overkill to change the oil every 3000 miles?


Does it void your warranty IF you only change it when the monitor says to? (which basically means that you would NOT be following what the owner's manual says)


I guess I'm confused why GM puts the "feature" in there, and then says change your oil every XXXX miles.


cadman_ks
 

·
Registered
Joined
·
612 Posts
"Is it overkill to change the oil every 3000 miles?"


Under most conditions I tend to believe it is, Years ago I had a good friend who was the owner of an old Gulf Oil (now BP) distribution plant. He told me that the 3,000 mile changes were nothing but a way to sale oil. I've always changed oil at 5,000 miles and do so for my convenience .... easy to look at odomoter and know when a change is needed ... Jim
 

·
Registered
Joined
·
444 Posts
I am using the "GM Oil Life" system for the very first time. I changed the oil the first time at 3000 miles just to clean out the initial wear in stuff. I now have 6,400 miles on the existing oil and no change message yet.

Driving History:

1. This oil use is through out the summer. I ride daily 15 highway miles each way to work. The coolant temp heats up to 200 degrees (It should be burning off the moisture and acids in the oil.)

2. Most local trips are long enough to heat up to the 200-degree coolant temp point.

3. I made several camping trips in the 100 to 500 mile each way range (Interstate high travel at 65 to 70 mph)

4. Had to add a quart of oil when I had 3000 and 6200 miles on the oil

5. Oil on dipstick is a medium to dark brownish in color at 6400 miles instead of clear.

I am going to change the oil in the next couple of weeks no matter what, just to put in 5W-40 oil for the winter. When I do change it, I am sending a sample out to Blackstone Labs for analysis. I'll share the results when I get it back.

BTW... I am using Chevron Delo 15W-40.
 

·
Registered
Joined
·
53 Posts
I agree with JEBar.


Years ago I was told of an article in Consumer Reports, where they took 2 vehicles and changed one at 3,000 and the other at the manual recommendation of 7,000. After 100k they evaluated both engines. Where was not any difference in internal wear on the parts. My Buick has the 'change oil' light and I have used it for over 100k miles. It still does not use oil between changes and it averages 6-7, between the light being activated.





Richard
 

·
Registered
Joined
·
315 Posts
I’m new to diesels so this may not apply, but the oil change interval for gassers has been 3,000 miles since before I was in short pants, and that’s a while. Now - on the gasser side again – oil performance over the last 20-30 years has improved dramatically, fuel injection systems have replaced carburetors/chokes that invariably washed the cylinders down with an overly rich mixture while the engine was warming up, etc. It’s easy to see oil change intervals being increased for gas engines.

What about diesels? Oil performance has improved for them as well. What about the engines themselves? Can one safely follow the recommended change interval calculated by the oil change system?

My truck is primarily used for my 100 mile a day commute, rarely used for towing. I’m juiced, but its not hot rodded. I don’t see my use as severe duty necessitating short change intervals. I change my oil every 5-6,000 miles. On my last change, the oil life system wasn’t reset, and it indicated an oil change was due at 8,060 miles.

For those who do oil analysis, what do your results show?
 

·
Registered
Joined
·
868 Posts
I have a 1980s era Mercedes diesel car with mechanical fuel injection. The oil turns black almost immediately. On the Duramax with electronic Bosch injection including pilot injection, the oil stays pretty much as clean as in a car.


I was a 3000 mile oil changer, and still am with the old Mercedes. But with the Duramax and my style driving with no heavy towing or city driving, I am moving up the confidence scale and going 6000 miles between oil and filter changes using Rotella T synthetic. Heck, the last change I even let it go 7500 miles, with the DIC saying I had 18% of oil life left.


Just remember to check the dipstick once in a while. You wouldn't want your dipstick to get dry!!
 

·
Registered
Joined
·
276 Posts
Discussion Starter #7
Iguess that my original question still remains.


..."IF this is GM's "official" position on oil life, then why do they tell you to change the oil on a regular basis in the owner's manual?"...


Why does it NOT say in the owner's manual, "Change the oil ONLY when the DIC says to change the oil. Changing the oil before this time is not needed and wasteful".


That's really in a nutshell what the GM article says, but that's not what they practice in the owner's manual...


cadman_ks
 

·
Registered
Joined
·
939 Posts
That's funny, I think my 03 owners manual specifically tells me to follow the DIC to change the oil. There is no set out 3,000, 5,000 or 7,500 mile oil change in my maintenance section. Just states to follow the OLM, but not to exceed 1 year between oil changes.


I'll have to crack open the manual again and verify though...


Bob
 

·
Registered
Joined
·
276 Posts
Discussion Starter #9
Now you got me to thinking.


I was going off of the schedule that they have in the manual, the one that you can use to write in all of the dates that you have scheduled work done.


I'll have to look to see what it specifically says about oil changing interval in regards to the DIC.


The other thing is that my dealer is the one that's ALWAYS telling me every 3500. Obviously my dealer hasn't read the article. Maybe I should print it off for the next time that I go in there.



cadman_ks
 

·
Registered
Joined
·
129 Posts
I've been changing mine every 3,000 but am about to go back to changing every 5,000 miles. My DIC didn't tell me to change my oil untill I got to about 15,000 miles
 

·
Registered
Joined
·
1,309 Posts
I am not a youngster anymore. I can remember changing oil before before the first 10-30 detergent came. We used 20 in the winter and 30 in the summer. The recommended change mileage was 3000 then. As someone said: Things have changed in the last 40 years. Later! Frank
 

·
Registered
Joined
·
939 Posts
Just checked it out... in my 03 diesel supplement manual on page 6-5 it states to use the oil system to change the engine oil and filter and that it is based on engine revolutions, and engine temperature, and on a maximum mileage of 10,000 miles (16 000 km). Not going to type the whole thing....


It also states not to drive the vehicle more than 10,000 miles or 12 months without an oil and filter change.


My maintenance schedule shows every 10,000 miles to check the OLM system, other than that, it doesn't show any type of severe driving or normal driving oil change schedule.....seems to me a $tealer could not void your warranty for doing 10k changes if the OLM says so...that's what GM says we can do on the 03's.


At this time, my oil life has me slated for 10k change based on my driving and the percent left showing on my DIC...question is, do I believe it is possible after all these years of "you must change your oil every xxx miles..."


Bob
 

·
Registered
Joined
·
276 Posts
Discussion Starter #13
I apologize. I just checked my manual, and it does say the same thing as what 4x4man stated. I had never really seen that in there, and I was confused thinking that my manual showed the schedule that you were supposed to use for oil changes. It just shows you to do things like rotating your tires, checking your axle fluids, change the Allison fluid, etc...


My schedule doesn't show the check the OLM every 10K. Maybe that's because the 2002 don't display the life left in the oil, or I don't know how to do that.


I don't really understand why my dealer is "pushing" me to do these 3500 mile changes. I guess that I should call them on the carpet on this one.


Like 4x4man also said, do I believe it is possible after all these years of "you must change your oil every xxx miles..." I guess that's really the $64 question. Does it ultimately hurt if you change at the DIC recommendation? I don't really see how GM can hold this against us if we do it at the recommended schedule...


cadman_ks
 

·
Registered
Joined
·
1,558 Posts
Well this is a tight situation. One on hand, GM gives a recomendation in their owners manual stating the oil change maximum life. On the other hand, while they have precise computer calculations estimating the oil life, they didn't add in a sensor to detect 'dirty oil'. So with all the possible variances in driving style and conditions, how to tell whether or not it's a reliable system?


Our 03 Trailblazer with the 4200 I6 says up to 12,000 miles. So what's the deal? Go to old school and change earlier? Rely on modern oil technologies and a computer program?


In my personal case, unless I do regular oil analysis, I feel more comfortable changing every 5-6000 miles on both vehicles(or if the light comes on sooner).
 

·
Registered
Joined
·
2,252 Posts
Wonder why they changed the temp to a higher point, wonder if this has anything to do with it
 

·
Registered
Joined
·
490 Posts
I have the "Cheap DIC" on my truck, no steering wheel buttons. By pushing the DIC stem, I can only access the main odometer, trip odometer, and engine hours. How do I access the OLM?
 

·
Registered
Joined
·
1,558 Posts
Except for the steering wheel additional controls I don't believe there is a way to read the oil life from our trucks. I know my Predator with it's onboard diagnostics does read the oil life. I would make AN ASSUMPTION ONLY that most OBDII readers would read this as well. Difficult to say since I've never used one, and was suprised to see it on there, than again it kind of makes sense.
 

·
Registered
Joined
·
444 Posts
Pick-
I have the same no button model like yours. According to the manual the display just above the steering column will flash "Change Oil Now" when it should be changed.

I cannot confirm that for sure, as mine has not flashed yet... I just hit 6,300 miles on this oil today.Edited by: JohnnyO
 

·
Registered
Joined
·
444 Posts
Just had a thought. The system is engineered to detect when to change the oil. How do we know the oil filter is still good and functioning after 6000 plus miles?
 

·
Registered
Joined
·
398 Posts
Mine seems to work just like a mileage indicator, it drops 1% for every 100 miles, has worked this way sense new. This will equal 10,000 mile oil changes.
I read the manual and I know it says it will monitor the engine temp and RPM to let you know when it's time for A change.
Mine has always been the same rather I run empty or tow my 11,000 LB 5th wheel.
 
1 - 20 of 23 Posts
Top