Is Your Gmt-900 Truck Or Suv Using Oil

[Jsdirt]

If they had just built the engines correctly right from the get, we wouldn't be commenting in this 45 page thread - Dexos, or no Dexos.

 

As far as I'm concerned, GM can take their Dexos and shove it where the sun don't shine ...

[Podor]

If they had just built the engines correctly right from the get, we wouldn't be commenting in this 45 page thread - Dexos, or no Dexos.

 

As far as I'm concerned, GM can take their Dexos and shove it where the sun don't shine ...

I'm right there with ya.

[lawn_star]

My GMT900 4,3L uses more oil than my GMT800 with 300,000+ miles

[GreenGreen]

2004 silverado Z71 5.3L iron block [215,650 miles] I run royal purple and go 3,500 miles between changes, my engine burns about 1 quart between changes. Dosent leak oil and no misfires. I do get lifter tick on startup

[Triki_Dick]

140,000 miles. Quart of oil every 1000 miles. Dealer did a top engine re-build at 60k and it's back.

 

Stuck piston rings is there excuse now, told me to pour marvels mystery oil in spark plug hole to help eat away carbon.

 

Just keep adding oil and driving.

[Cowpie]

It is a sad testament to GM quality. My factory remanned 12.7L Detroit, 704,000 miles into its second life, only uses about 1 qt per 10,000 miles. Just did oil change on it at 21,580 miles on the oil and it only used 2 qt.

Edited June 19, 2017 by Cowpie

[robroy]

A couple of notes for the thread; for the "privilege" of living here in California I had to get my truck smogged and the smog check up does not like what ever the Range AFM disabler does to the system. If you are due for a smog check and running a programer, disable the programer 60-100 miles before your smog test. After I pulled the plug on my range, and drove for a week, she passed just fine.

I am done with synthetic oil. Two changes ago I switched to delo400 (15W-40) and the difference, while the sample size is small and the observations empirical, are positive. I hear less valve slap, I hold more consistent oil pressure on the gauge, and burn less oil, though I am changing it 4,000 miles instead of approximately 10,000 when the computer told me to change it, so theres less time to burn oil between changes.

[Cowpie]

As long as the HDEO also meets gasoline API SN, shouldn't be an issue. I have used HDEO oils in gas engines.

[Northman]

A couple of notes for the thread; for the "privilege" of living here in California I had to get my truck smogged and the smog check up does not like what ever the Range AFM disabler does to the system. If you are due for a smog check and running a programer, disable the programer 60-100 miles before your smog test. After I pulled the plug on my range, and drove for a week, she passed just fine.

I am done with synthetic oil. Two changes ago I switched to delo400 (15W-40) and the difference, while the sample size is small and the observations empirical, are positive. I hear less valve slap, I hold more consistent oil pressure on the gauge, and burn less oil, though I am changing it 4,000 miles instead of approximately 10,000 when the computer told me to change it, so theres less time to burn oil between changes.

I'm going to try using a synthetic 5w-40 diesel oil this time hoping the high detergent oil will help clean the rings. I have tried the Marvin's Mystery oil in the oil approximately 65 miles before I changed it. It seemed to help for awhile. I had better oil pressure and less smoke afterwards. We'll see how the 5W-40 works. If it helps I'll let you know.

[Cowpie]

Use a synthetic or semi syn 10w30. Get the same HDEO package as with a 5w40.

[Northman]

I'm going to try using a synthetic 5w-40 diesel oil this time hoping the high detergent oil will help clean the rings. I have tried the Marvin's Mystery oil in the oil approximately 65 miles before I changed it. It seemed to help for awhile. I had better oil pressure and less smoke afterwards. We'll see how the 5W-40 works. If it helps I'll let you know.

We'll using 5w40 seems to be helping a lot. I have about 75% less smoke at start up and so far after about 700 miles the oil is still full. Oil pressure is holding about 40 as well. Used to drop to under 30 at highway speeds with 5w30 conventional.

[Cowpie]

I had an oil burning issue with my 2006 Cadillac CTS 3.6L. Put on a catch can and changed to Pennzoil 10w30 conventional and it cleaned things up pretty good. Plan of keeping the car for a lot longer. According to the Petroleum Quality Institute of America testing, the PYB 10w30 has a very stout additive package with a great level of detergents. There are many good options. If I hadn't done what I did and gotten good results, I would have been inclined to go the similar route you did, Northman.

[eddiefromcali]

minimal/no loss with my 05 LM7, 206k miles running Amsoil since 100k. My catch can MIGHT have a few ounces, 1-3oz in 5-6k miles.

[Northman]

We'll using 5w40 seems to be helping a lot. I have about 75% less smoke at start up and so far after about 700 miles the oil is still full. Oil pressure is holding about 40 as well. Used to drop to under 30 at highway speeds with 5w30 conventional.

1200 miles. Checked oil this am and it was just a little under the full mark. Oil pressure still strong. Looks like its working. My wife is taking it to MN this weekend to bring my grandson back to his mama. Its about 600 miles round trip. I'll check it when she gets back and let you know what it says.

[need-for-speed]

Well I figured I was imune, but I'm not LOL. My wife's 2008 Tahoe with 130K miles had no oil showing on the dipstick!! It was 1.5 quart low at 30% OLM. I read the first 100 posts of this thread and then skipped to,the end. Was there ever a discussion of cause? Do the inactivated cylinders suck in oil due to closed valves (high vacuum) and then the rings carbo up and then don't seal well? That's the only thing I can think of. Or is there some other mechanism leading. To,the oil consumption?

 

If I install the Range, will the engine clean up on its own?