BUICK11 Posted July 1, 2010 Report Share Posted July 1, 2010 Just for the fun of it I had a Oil Analysis done on our 2008 STS V-6 with 11,500 mi on it. I was curious about the oil turning Black almost immediately after changing it with Mobil-1. Which has been used from the first day. The analysis was done by Blackstone Labs in Ft. Wayne In. The oil had 2891 Mi on it and was just about 1 year old. Car was purchased new and has been well serviced. I am dissapointed with the results. Here is what they reported. "Wear was generally above average,but nothing was in the problem range. Iron comes from steel parts like cylinders,while copper is from brass/bronze bushings and bearings.Universal averages for the 3.6L show normal wear after -5000 miles use of oil.Some fuel was present and this could explain some of the dark oil color you mentioned.Insolubles might also be considered high for oil run just 2891 miles. The TBN was strong at 3.8 so lots of aditive was left. 1.0 is low. At this point, we found no smoking gun for the dark oil. Check Back". I have not discussed this with the dealer and do not think it would be worthwhile. Any comments would be appreciated. Thanks Charlie Link to comment Share on other sites More sharing options...
Cadillac Jim Posted July 1, 2010 Report Share Posted July 1, 2010 Excessive fuel in the oil tells me that the PCV system might not be working as designed. It won't throw a code but is one of the most important mechanisms for long engine life because it keeps blowby from collecting in the oil. -- Click Here for CaddyInfo page on "How To" Read Your OBD Codes-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data -- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC Yes, I was Jims_97_ETC before I changed cars. Link to comment Share on other sites More sharing options...
BUICK11 Posted July 1, 2010 Author Report Share Posted July 1, 2010 Thanks for the tip! I am looking for ideas, it is a nice car and we would like to keep for a while. Link to comment Share on other sites More sharing options...
BodybyFisher Posted July 1, 2010 Report Share Posted July 1, 2010 I would run it a few times before I drew any conclusions. I was under the impression that oil turning black right away was not an issue Marika has done the oil testing through Blackstone also see this thread, and look at her history on the Blackstone report, she has done the testing 6 times now, Blackstone told her that the parameters would get better over time. Do a search under Marika, I dont know why her old threads are not available, BRUCE? http://caddyinfo.ipbhost.com/index.php?showtopic=20599&st=0&p=139981&hl=blackstone&fromsearch=1entry139981 Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
BUICK11 Posted July 1, 2010 Author Report Share Posted July 1, 2010 Under normal circumstances I would agree that Black may not be bad. But in this situation coupled with the oil Analysis I feel it has to be looked at. Already looked at PCV hoses and found all were OK Thanks Link to comment Share on other sites More sharing options...
JohnnyG Posted July 1, 2010 Report Share Posted July 1, 2010 Interpreting oil analysis reports can be tricky business, Blackstone would have flagged any parameters that indicated pending engine damage so I'd say you are OK. Oil color is absolutely no indication of its ability to lubricate your engine, and should not be too big of a concern. You can look at it from the standpoint that the oil is cleaning your engine as it turns black, and the dirt is better off in your oil than it is in the engine. Some things you should consider: 1) the cleanliness of the air filter, which (according to my Caddy dealer) can cause excessive oil burning. 2) Any driving style that can lead to overly rich mixtures in the engine (lots of cold starts, lots of full throttle acceleration, or just plain lots of stop and go driving) 3) Any engine condition which could lead to a rich fuel mixture such as a leaking injector or leaking fuel regulator. Since there was not excessive fuel in the oil, that means that Blackstone ruled these last items out for you. I drove an SRX for a little while with that same engine in it, the oil was MUCH blacker than I've ever seen it on my Northstar. I mean it was completely black on the dipstick, couldn't see throug it at all. Maybe this is just normal for that engine. Never underestimate the amount of a persons greed. Link to comment Share on other sites More sharing options...
BodybyFisher Posted July 1, 2010 Report Share Posted July 1, 2010 It would be interesting to see the emissions system in detail on this engine to see if that is a cause. Times like this is when I miss Bbobynski Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
BodybyFisher Posted July 1, 2010 Report Share Posted July 1, 2010 See this, I found the discussion interesting http://www.team-bhp.com/forum/technical-stuff/19700-why-does-engine-oil-go-black-immediately.html Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
BUICK11 Posted July 1, 2010 Author Report Share Posted July 1, 2010 Thanks to all. We really like this car, what concerns me is that such a nice low mileage car comes back with "Wear was generally above average" and that all the paramaters were on the high mark. May talk to a few cadillac tech's for their thoughts. I am thinking that the Direct Injection motor may have something to do with it. Will advise if I find anything conclusive. Charlie Link to comment Share on other sites More sharing options...
Cadillac Jim Posted July 1, 2010 Report Share Posted July 1, 2010 Check the PCV valve -- pull it out of the cam cover and see if it rattles easily and isn't stuck. Also, start the engine and see if you have vacuum at the PCV valve opening that goes into the cam cover. -- Click Here for CaddyInfo page on "How To" Read Your OBD Codes-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data -- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC Yes, I was Jims_97_ETC before I changed cars. Link to comment Share on other sites More sharing options...
KHE Posted July 1, 2010 Report Share Posted July 1, 2010 I think you're getting worked up over nothing. Drive and enjoy the car. Kevin '93 Fleetwood Brougham '05 Deville '04 Deville 2013 Silverado Z71 Link to comment Share on other sites More sharing options...
BodybyFisher Posted July 1, 2010 Report Share Posted July 1, 2010 I wrote to Blackstone for their opinion on this, lets see what they say, hopefully they will chime in here Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
Ranger Posted July 2, 2010 Report Share Posted July 2, 2010 I think you're getting worked up over nothing. Drive and enjoy the car. I couldn't agree more. Link to comment Share on other sites More sharing options...
Texas Jim Posted July 2, 2010 Report Share Posted July 2, 2010 This is what I noticed.... The oil had 2891 Mi on it and was just about 1 year old The oil is year old... It has less than 3000 miles on it... That indicates that the car doesn't get driven much and likely has a lot of start cycles where it never fully warms up. Personally... I would consider that "SEVERE DUTY"...and change the oil a lot more often. Just my opinion.... Link to comment Share on other sites More sharing options...
BUICK11 Posted July 2, 2010 Author Report Share Posted July 2, 2010 Thanks to all! The car is driven by my wife. I use the oil life monitor or ONCE a year for the Mobil 1 changes. This is what the manual recommends. As you can see she does not drive it a lot. We have 4 cars thus it does not get driven a lot, which could be part of the problem. If it is something simple like a PCV system not functioning properly I would like to get it repaired before it shortens the engine life. If it was "SEVERE DUTY" would the OLM not tell us to change the oil? Thanks Charlie Link to comment Share on other sites More sharing options...
BodybyFisher Posted July 2, 2010 Report Share Posted July 2, 2010 This came out of my manual, the oil life monitor description in the owners manual from your glove compartment, it does not track TIME, I dont believe based on this description Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
BUICK11 Posted July 2, 2010 Author Report Share Posted July 2, 2010 That is exactly what I do. It was one year so I changed it. The OLM indicated their was 85% left on the oil. I would think that in view of all the short trips the OLM would have advised to change earlier? Perhaps I may chnge it twice a year just for peace of mind! Thanks Link to comment Share on other sites More sharing options...
BodybyFisher Posted July 2, 2010 Report Share Posted July 2, 2010 Its interesting that you mention this, yes, I think that the short trips would drop the oil life more than that. Short trips are the worst for oil, its the long trips that boils out moisture, impurities and fuel. The oil life monitor is a very good indicator of oil life, but in this case, it does not seem to have done its job, could it have been accidently reset? I do not believe that disconnecting the battery resets the OLM, can someone confirm that? Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
Texas Jim Posted July 2, 2010 Report Share Posted July 2, 2010 Thanks to all! The car is driven by my wife. I use the oil life monitor or ONCE a year for the Mobil 1 changes. This is what the manual recommends. As you can see she does not drive it a lot. We have 4 cars thus it does not get driven a lot, which could be part of the problem. If it is something simple like a PCV system not functioning properly I would like to get it repaired before it shortens the engine life. If it was "SEVERE DUTY" would the OLM not tell us to change the oil? Thanks Charlie Charlie, I doubt that it would tell you that. There is a section over in the back of the manual that gives some guidelines for severe service. The statement I made was just my opinion only. I was just thinking... Not driven much... Engine doesn't run long enough at a time, at full operating temp, to burn off the condensation and contaminants from each cold start... The rest of the time the oil is just soaking it all up... Heck...mine is run a "LOT"...and mostly freeway and Interstate driving. I still change the oil at about 40 percent remaining. It is almost as clean when I change it as it was when I put it in the car. Oil is cheap Engines are expensive. I would rather change oil than engines... I am not criticizing you for using the OLM... I think the OLM is great, but "SOMETIMES"it should be used as a guideline and you need to take your individual driving habits into consideration when thinking about the oil changes. Again...this is just my personal opinions and what "I"do. Link to comment Share on other sites More sharing options...
BUICK11 Posted July 2, 2010 Author Report Share Posted July 2, 2010 The OLM was not reset by accident. I changed the oil on the one year anniversary. I have always been a fanatic on oil changes but have read so much about the GM OLM I decided to use it or the one year mark. I think I will change it twice a year and do a couple more Oil analysis on the car just to check it out. Charlie Link to comment Share on other sites More sharing options...
BodybyFisher Posted July 2, 2010 Report Share Posted July 2, 2010 The OLM is very very good, I do not understand its performance in this instance, it is possible that the low mileage is not enough to trigger a decrease and that is the reason why they recommend a change at 1 year. NOW, I understand the questionable state of the oil by Blackstone. I still can't help but wonder why the short trips didnt trigger a greater drop than 85%. How often is this car driven, daily, weekly? Pre-1995 - DTC codes OBD1 >> 1996 and newer - DTC codes OBD2 >> https://www.obd-codes.com/trouble_codes/gm/obd_codes.htm How to check for codes Caddyinfo How To Technical Archive >> http://www.caddyinfo.com/wordpress/cadillac-how-to-faq/ Cadillac History & Specifications Year by Year http://www.motorera.com/cadillac/index.htm Link to comment Share on other sites More sharing options...
Cadillac Jim Posted July 2, 2010 Report Share Posted July 2, 2010 I noticed the low mileage and the age of a year but didn't focus on it as the likely cause of the problem, as did Texas Jim. If the PCV valve rattles and you can get vacuum on it when you start the car, it's OK and you can leave it alone. Sometimes the best thing for a car is an oil change, a fresh tank of gas, and a 500-mile road trip. You might try that. -- Click Here for CaddyInfo page on "How To" Read Your OBD Codes-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data -- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC Yes, I was Jims_97_ETC before I changed cars. Link to comment Share on other sites More sharing options...
BUICK11 Posted July 2, 2010 Author Report Share Posted July 2, 2010 Once again Thanks to all for your input. The car is my wife's around town car. It is driven daily. On occasion I get to drive it and I run it hard. We have a DTS we use for the road. I spoke to a GM Tech today and he indicated that GM is starting to have some sluge problems with the 3.6 motor in addition to cam problems. He feels that twice a year would be best for us. So much for the OLM. As I said I will retest the oill again in November when I change it. By the way I have a 1989 Riviera that I have faithfully changed the oil and filter every 3 months. over 300K on motor Charlie Link to comment Share on other sites More sharing options...
Ranger Posted July 3, 2010 Report Share Posted July 3, 2010 I noticed the low mileage and the age of a year but didn't focus on it as the likely cause of the problem, as did Texas Jim. If the PCV valve rattles and you can get vacuum on it when you start the car, it's OK and you can leave it alone. Sometimes the best thing for a car is an oil change, a fresh tank of gas, and a 500-mile road trip. You might try that. Jim, the 2000+ Northstars do not have a rattle can PCV valve. They just have a fixed orifice. Link to comment Share on other sites More sharing options...
Cadillac Jim Posted July 3, 2010 Report Share Posted July 3, 2010 Ranger -- thanks; I'll watch for the 2000+ cars. So, if it gets a vacuum with the engine at idle, it's probably good. -- Click Here for CaddyInfo page on "How To" Read Your OBD Codes-- Click Here for my personal page to download my OBD code list as an Excel file, plus other Cadillac data -- See my CaddyInfo car blogs: 2011 CTS-V, 1997 ETC Yes, I was Jims_97_ETC before I changed cars. Link to comment Share on other sites More sharing options...
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