Home Forums Hunting & Shooting Hunter's Campfire GM truck owners 2019-present 5.3,6.2

Have this in the truck forum, but thought it might get more mileage here.



Thought I would share some real world info.

My truck 2021 Sierra 5.3 (bought March 2021 before everything went hay wire with the chips)
Mileage: 13,450
Best highway mileage:22.8 (Cruise set at 75)
Combined mileage: around 14.8 (most of my driving is around town)

I found that on a couple trips in the 800 mile range, I used around a quart of oil. Normal driving, wouldn't use a drop.

I knew about the lifter issues going in, but maybe not that it was so prevalent. So I decided to put the Pulsar LT on my truck. Can't get rid of the lifters, but decided I would turn off the DFM. This will in also disable the start/stop. Unit also allows throttle response changes, and speedometer limit changes. I set the throttle response to level 3, and the speedometer to 140 mph. (it does several other things with tire size, TPMS changes, etc that I didn't fool with). The difference in drivability is crazy good. Throttle response on the highway is so much better with all 8 pulling all the time. Before, the truck was a dog when trying to accelerate at highway speeds. Seemed to be a delay with coming back on to 8 cylinders and trying to drop down the the right gear. Not so anymore.

So, took it on anther 600 mile jaunt last week with the new set up.

Highway mileage there: 21.9 (cruise set at 75)
Highway mileage back: 19.2 (running 80-82 cruise used only occasionally)

Pulled the dipstick....dead on full. Oil has right at 3500 miles on it. This obviously shows the DFM is responsible for the burning oil, which I suspected all along.

So, I got 1mpg less running on all 8 all the time, better throttle response to overtake on the interstate, and no oil consumption. WIN,WIN,WIN
Not saying it will prevent a lifter issue, but if the lifter solenoids aren't being activated 80 times a second......Well it's peace of mind for me.

Pulsar LT will run you about $500. It takes 10 minutes to install, and 20 minutes or so to program to your liking. According to the website, it does not void warranty. It doesn't upload a program, just interrupts inputs so to speak. However, I can say, if it needs warranty work for any reason, I can pull it off and it will go back to factory settings.

By the way, I hand calculated the mileage, and found the computer to be spot on. I have no part of Pulsar, but just wanted to pass on my experience with their product.
https://www.rangetechnology.com/products/pulsar_lt/parts/22451



Clyde

P.S. I know there will be the gnashing of teeth, Ford, Toyota, Dodge blah,blah,blah. But it was my money. Fire away

Sounds good. I've got an older Silverado 5.3 and have thought about getting a "tune" on it.

I hear ya . I have a 2015 chevy 5.3 and I am running a ( range -300 ) to keep it in all 8 $230 on ebay just plug it in the diognostic port and go . it cost me about 1 mile per gal but after reading about the 5.3 dropping valves it is worth it

I had a 15 Chevy with a 5.3 usually around 20 mpg. it ran 4 cylinder 8 cylinder. Mine used a qt per oil change..Traded at150 K for a 22 GMC. 5.3
It is 8 cyl. all the time and is getting better mileage.

So that's what is burning the oil. I have a 20 Silverado with the 2.7 and even though it is just a 4 banger it has the cylinder deactivation. I'm adding oil every month

Obligatory "not a Chevy disclaimer"......


It seems to me that in the last 10 years, aftermarket tunes solve an awful lot of problems that should be corrected by the factory and/dealership. For example, Ram Ecodiesels tend to grenade if they stay factory. Tune solves that issue, much like your fix solves your oil burning. Sure would be nice if they came correct from the factory, that's across the board for a the money we spend.

Well said

First thing I did when I bought my 2017 5.3 was put a Range on it. It hasn't been out of V-8 since I drove it home from the dealer.

Long time known problem since AFM got started with 2007 models.

This.

I am a lucky one. 70k and no oil burned with 10k change intervals.

I will eventually do an AFM/DOD delete and do a cam swap and probably a set of GM performance heads.

I have a '21 with a 6.3 and I also installed a Pulsar. Also added an oil-catch can and an air intake. V-8s are supposed to run on all 8 all the time. If I wanted a 4 cyl, I would have bought a 4 cyl. Seems like the DFM is an over engineered complicated system of no real benefit except repair revenue to GM.

Take a look at a you tube video of the replacement. I was convincingly unimpressed with the engineering. Take something that moves thousands of times a minute, and make it a weak link. Brilliant.

How many miles/length of time with your Pulsar?

Clyde

How do these aftermarket tunes/software affect the factory warranty?

I wouldn’t own a modern vehicle that used oil, been driving EcoBoost F150’s since 2012 and never had any problems with oil consumption.

The Pulsar is removable and the vehicle resets back to factory settings. Doesn't effect the warranty.

Had the truck almost a year,but only 4000 miles on it. You're spot on with the weak link.

With all the vehicle electronics they’re not able to tell that something aftermarket has ever been on there?

No

FWIW - they likely can tell. Lots depends on GM - I know CAT used to require an ECM download for every warranty repair, regardless of reason. I don't know if GM does. I'd think the ECM would keep track of how often or hours/duration the truck ran on less than 8 cylinders. You show up with 28,000 miles on the truck and it shows it was less than 8 cyl 3 total times - GM will know something was up but probably not exactly what was up.

Now PROVING that is the cause of your failure is something else entirely as would be required by the Magnuson Moss act.

That said - I know of only one situation where the tune can void a powertrain warranty without it causing an issue - Harley Davidson a while back got in trouble with EPA because dealers would load/set up tunes that weren't EPA compliant. Air cooled engine had to be run rather lean to meet emissions. Common tune was to fatten them up to cool things a bit and provide power. Hard to do in an EPA tune. So if you have a HD and do a tune on the bike that is outside of EPA (almost all are except the Screaming Eagle tuner) - HD is forced to terminate the warranty (powertrain) on your bike - regardless of issue or cause. Bikes are essentially flagged at the vin level in the warranty software at the MoCo. Deal Harley cut with the EPA back in the day. May be void now with SCOTUS - don't know.

Now - given the warranty is short on a bike - not really a huge deal and Harley's are relatively easy to repair yourself (no, seriously, the hardware on a HD is pretty basic, just need to think about it a little) most guys aren't too wound up about it. And even if you have an extended warranty that gets voided - it's powertrain, not electronics so you're likely still pretty ok - if your dealer is decent. Mine's decent - they get it and will do what they can to help you/protect you.

Jack, the Pulsar isn't really a program. You are not required to download the factory tune, and install the upgraded tune to the vehicles computer. That would be a sure sign a GM tech would see. This is a pigtail that installs directly to the main harness, and sort of interrupts, for lack of a better term, the commands to turn on the DFM. But as Teal said above, there is probably a way for them to know length of time the truck runs in 8 cyl mode as apposed to the DFM working. But, the unit can be removed, and the truck will go back to factory settings. Pulsar is insistent that it will NOT void the warranty.


Clyde

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