What do you do about oil usage?

Cowpie · August 5, 2016

This is what the situation was with a 2006 Cadillac CTS 3.6L I bought a couple of months ago with 52,000 miles on it. Learned real quick it was a serious oil eater. About 1 qt to 1000 miles. Other than that, a immaculate car that was worth every bit of $9K I paid for it.

Dealer changed oil when I purchased it. Realized right away oil level was dropping pretty quickly. I did an engine flush on it and changed oil a couple weeks after purchase. Used a 5w30 synthetic. Also installed a Elite engineering E2 catch can on the PCV to see how much oil was going thru there. A lot. About 1.5 oz per 100 miles.

Let it go for 2000 miles, then did another engine flush and oil change and put in a 10w30 synthetic. 2 weeks and about 400 miles and oil level hasn't changed on stick, and catch can captured, maybe, about 1.5 oz of oil. A massive change in consumption. Almost non existent compared to earlier. At the time on this oil, I would have had been almost 1/2 qt low on stick previously.

Had to be a lot of blowby to cause so much oil to be going thru the PCV line. A couple of engine flush treatments with oil changes over a 2000 mile interval must have gotten rings cleaned up and sealing better. Might be an approach to take by anyone with a oil burner on their hands.

markpa · August 6, 2016

Can you leave a range device plugged in all the time? Even if you do not drive it daily or will it kill the battery?

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flyboyron · August 6, 2016

I ordered the new valve cover and should have it on Monday. It comes with the seals for the bolts and the valve cover gasket. I have the Range coming and should have that on Tuesday. I have scheduled the truck for a local shop to change the oil and install the valve cover on Wednesday.

I think between these two fixes, I should have this problem licked. I am hoping that it hasn't ruined the rings yet.

What gets me is that GM knew about this valve cover problem and they notify the dealers, but most dealers don't go and tell their customers who bought cars from them about any TSB's.

It is just like the TSB about the drive shaft. When I bought my truck, when I came to a stop and released the brakes, the truck would make a thump noise, felt like I had just been hit by the car behind me. When I talked to the service dept about it, they said I had to grease the U-joints every 10,000 miles. I never heard of that.

Then, reading on this board, someone mentioned a TSB about that problem and I went down and asked about it and got the U-joints replaced and the problem was solved.

Looks like this board is really helping me out.

Thanks guys.

arcasey · August 7, 2016

This is what the situation was with a 2006 Cadillac CTS 3.6L I bought a couple of months ago with 52,000 miles on it. Learned real quick it was a serious oil eater. About 1 qt to 1000 miles. Other than that, a immaculate car that was worth every bit of $9K I paid for it.

Dealer changed oil when I purchased it. Realized right away oil level was dropping pretty quickly. I did an engine flush on it and changed oil a couple weeks after purchase. Used a 5w30 synthetic. Also installed a Elite engineering E2 catch can on the PCV to see how much oil was going thru there. A lot. About 1.5 oz per 100 miles.

Let it go for 2000 miles, then did another engine flush and oil change and put in a 10w30 synthetic. 2 weeks and about 400 miles and oil level hasn't changed on stick, and catch can captured, maybe, about 1.5 oz of oil. A massive change in consumption. Almost non existent compared to earlier. At the time on this oil, I would have had been almost 1/2 qt low on stick previously.

Had to be a lot of blowby to cause so much oil to be going thru the PCV line. A couple of engine flush treatments with oil changes over a 2000 mile interval must have gotten rings cleaned up and sealing better. Might be an approach to take by anyone with a oil burner on their hands.

I think blowby was probably the issue but what has most likely fixed or suppressed your issue is the heavier weight oil that you used. It would be harder for the heavy/thicker oil to finds its way into small spaces to form the blowby. One thing to be mindful of (Although in all honesty it won't hurt a thing in the world) but vehicles are designed to run a certain weight oil for adequate lubrication. The oil pumps are also made for whatever the design weight was intended to be. Just as a disclaimer it is never a good idea to use a different weight oil than the vehicle was designed to run with to ensure adequate lubrication, but as I mentioned above it probably won't hurt it.

Cowpie · August 7, 2016

True, engines are designed with a certain weight oil in mind, but your assertion that I used a different weight oil is incorrect. I didn't use a heavier, different weight, different viscosity oil. A 0w30, a 5w30, or a 10w30 are all 30w oils and have the same kinematic viscosity at operating temperature. That's ok, a common misconception by many folks that they are different weights. The only thing different between these oils I mention is the cold flow rate. The "w" doesn't stand for weight, it stands for winter. Check with the API website, it says so. The 10w30 does have a much lower NOACK (burn off vaporization rate) than the others, simply because it is more base oil with less viscosity improvers (VI can shear and break down under many conditions) because it doesn't need as much. Take a look at this chart, especially the 0w30, 5w30, and 10w30. The kinematic viscosity at 100c in virtually identical. They are a same weight oil, with a kinematic viscosity of around 10.4 to 10.5. Also, viscosity is not thickness. It is resistance to flow. Ask Isaac Newton in the next life and he'll explain it to you. So, contrary to your assertion, I did use a viscosity of oil recommended by GM (30w). I just used one that has a slightly higher winter flow rate. The oil pump will have the same work to do with a 0w30, 5w30, or 10w30 at operating temperature. And bearings, cams, rings, etc will not notice a difference either at operating temperature. Only at cold start up would the pump notice anything different, and then, with a 10w30, only if I was in extreme cold.

The only reason GM recommends a 5w30 many times is to cover the broad range of users from the Rio Grande to Canada. Someone is south Texas would never see the need for the cold flow rate of a 5w30, but it would work. While someone in Duluth, MN in the winter would definitely benefit from a 5w30. So GM just blanket proclaims that they recommend a 5w30. They realize that many folks make the same mistake you did and they just account for that. And using the same mindset, that is why they never allow a 10w30 on the approved dexos1 oil list, even though in many cases, a 10w30 will outperform (because of being more shear stable and other factors) a 5w30 or 0w30.

I know this is new to a lot of folks, but relax, there won't be a test next Friday on it!

flyboyron · August 7, 2016

Can you leave a range device plugged in all the time? Even if you do not drive it daily or will it kill the battery?

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I plan on leaving mine in except when I am not driving it more than 2 or 3 days. I found this on their website....

The Range Device does NOT draw much on the vehicle battery during normal operation. If you drive your vehicle daily (or almost daily), then this will not be a concern. However, if you drive your vehicle infrequently (i.e., only on weekends), please remove the device. It is best practice to remove the device if your vehicle will sit for anything longer than 3-4 days.

To add some more detail:

The device will go to a VERY low "sleep" state after the engine is off (within 3-10 seconds of the engine shutting off)
In this state all the LEDs are OFF and it hibernates at about 1-3mA
Every 7-15 seconds it will wake up to a "light sleep" state to check to see if the vehicle is running. In this mode, there will still be NO LEDS lit but current draw will spike for < 0.1 sec to about 7-10mA.
If the vehicle is NOT running (i.e. RPM < 500) then it'll go back to deep sleep. Rinse and repeat until the vehicle is running, at which time it'll fire up completely and you'll start seeing LEDs light again.

Given this and the normal draw from other modules (a modern vehicle will always have a small draw for the security systems, BCM, remote start/locks, OnStar, etc. .. sometimes as much a 50mA), it is recommended to reduce the risk of battery depletion by unplugging the module when the vehicle is going to be sitting for an extended period. Cold weather, weak charge state, age, etc. can all contribute to less battery capacity.

A healthy battery with decent capacity should be able to go much longer than the recommended length of time but it worth it not to come out from a 2 week vacation and find the battery dead in the airport parking lot!

WilliamBos · August 7, 2016

A superchips flaspaq or a Diablo I2 is another way to tune the afm off.

Cowpie · August 11, 2016

When I had a previous 1500 with 5.3L, I used the first edition of the Range device to shut down AFM. I just left it in the OBD port and didn't pay any attention to it. Sometimes pickup sat for over a week, and I never had any battery issues. I suppose with a battery that is about to conk out anyway, it could be a problem.

markpa · August 11, 2016

Got the range on Monday and plugged her in. Seems to do what it says shuts down AFM. Will have to monitor gas mileage and oil use. I did not have much of an oil usage issue. 3/4 qt in 5000 miles. I just like the idea of always having a V8. Has to be better for stresses on the engine and smoothness. Don't really care if I lose 1 mpg. I'm usually pulling something 50% of the time anyway.

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Cowpie · August 11, 2016

That was one of my reasonings when I had a 1500 5.3L.... I am an old Army Cavalry Sergeant who thinks everyone should pack the gear. No slackers. I didn't want some of the cylinders taking union and government sponsored rest breaks while the other cylinders did all the heavy lifting. And even from a amateurish mechanical view, I could visualize oil getting by rings on shut down cylinders and being a problem over time. Of all the ways to improve fuel economy, it seems like a very lame way to go about it. Just glad the 6.0L in my 2500 doesn't have this nonsense. Scotty on Star Trek was right.... the more complicated one makes the plumbing, the easier it is to stop up the drain.

Dnt · September 28, 2016

Traded my 2009 5.3 sierra oil burner at around 85000 miles I had to keep a 5quart jug of 5w30 in the truck. The dealership finally did some work on it new valve cover/deflector in oil pan etc after I went through their oil consumption test thing a couple of times. The last straw for me was when it started fouling spark plugs out due to oil consumption and smoked like a coal train when starting. I have no idea if what they did to it fixed the oil consumption problem or not since as soon as they were done I traded it on a 2014 sierra. I never had to add a drop of oil between oil changes on the 2014 5.3 and drove it right to the oil change monitor 8 t0 10000 miles between changes I had 62000 on it when I traded the 14 for this 2016 6.2. Here is a pic of one of the fouled plugs from the 2009 5.3

wehowardjr · September 28, 2016

I bought a Range AFM disabler nearly 3000 miles ago and have had zero oil consumption. I use 5W-30 Mobile 1 full synthetic. Before the Range I was using 1/2 quart every 2500 miles. Leave it plugged in 24/7 and haven't had any battery issues. The end of this week or first of next I am buying a Diablo inTune with a custom tune from Lew. I will be posting my Range AFM for sale when I get my Diablo.