EcoTec3 5.3 L84 DFM oil consumption

[Aggie06]

Thought I would start a thread on this as it’s something I am dealing with. The L84 5.3 with dynamic fuel management (DFM) is the engine in question. It’s in a 2019 Chevy 1500.

Similar to older 5.3s, Chevrolet considers burning less than a quart in 2k miles within spec. The dealer oil consumption test tracks usage over 2k miles after an oil change. If it burns over a quart during that interval, no further action is warranted.

Much like the AFM trucks, the DFM equipped trucks like to consume oil and have been having issues with lifters failing.

The DFM engines have something like 17 different cylinder patterns that it can operate in vs. AFM either operating in 4 or 8 cylinder modes.

My truck currently has around 41k on it. Really saw an uptick in consumption after 30k. At 36K, It was over 2 qts low which would have been around 5K on the oil change. My plan it to catch and more accurately measure the oil level when I change the oil again.

There is also concern of carbon buildup in the intake ports due to the engine being direct injected. With oil being lost somewhere, I added a catch can to the truck to capture some of the oil vapor that was being fed back to the intake through the pcv system.

I checked its level at 1k after install (~40500 miles). The can held around 9 mls of oily liquid at that point.

Edit: Will add more to this post when I have free time later.

 

[Aggie06]

Checked the catch can today at 41684 miles and had collected 12 mls of oily liquid. That makes 21 mls in ~2k miles. Using the short average of 10 mls per 1k miles would add 52.5 mls of that liquid into the intake over 5K miles.

 

[gmcxt]

Run a cleaner kit like BG at every oil change.
EPR, MOA, and 44k

If there is any carbon build up causing a ring sealing issues this WILL help. If it doesn't help carbon deposits is NOT your problem.

To turn off the cylinders they keep the valves closed. To keep the valves closed, the lifters collapse inside them selves rather than push the push rods up to move the rocker arms which push open the valves. When both valves are closed and the piston accelerates down a small volume of space is "stretched" there by creating a large chamber with high vacuum. This draws oil up past the rings into the cylinder and causes the consumption.

There is no way around it with this design. Buy an OBD 2 plug in disabler for $300.

 

[gmcxt]

 

[Aggie06]

gmcxt Thanks.

I have thought about buying a pulsar lt to turn of the DFM and auto start/stop. From what I can find, changing the lifters is more expensive on DFM trucks vs. the older AFM. Also, programming is expensive if you go down that route.

 

[gmcxt]

If we can find some really smart guy on here who is familiar with the big picture program called Unified Diagnostic Services that can hack and code things through a secured gateway, we could make these expensive to repair problems go aways. Simply telling the ECM to not to turn them on or change some enabling criteria threshold to some outlandish value would probably keep it off yet pass an inspection.

 

[Aggie06]

My concern is will the lifters fail or make it for the life of the truck. The 2021s have had a run of and lifters, but failures have been early on. The 2019s seem to be hit or miss. Some people are getting on 100k without issues, and some had early failures. If they eat it out of warranty, I’m all for hard deleting stuff.

 

[Aggie06]

Slight update and cross post from chit chat. I collected 40 mls in the catch can on my 2019 in the 3783 miles it has been installed. That’s around 0.5% of the total volume of the oil change going through the PCV system.

I used BG kit recommended above when changing the oil yesterday. Will see how things go during the next cycle.

 

[Grendel]

I turn it off in HPTuners.

In customer cars, I go with LS7 lifters and a different cam, mainly for power, but also to get rid of it.

 

[Aggie06]

I turn it off in HPTuners.

In customer cars, I go with LS7 lifters and a different cam, mainly for power, but also to get rid of it.

Is that for the current Gen with dfm? I haven’t found any reliable information on it. Other than programming might be expensive.

 

[JohnnyJ]

it won't help the intake, but if you run a tank of e85 thru it here and there on long road trips, that will clean out the cylinders. Letting a truck sit around with e85 can cause issues, but I've seen pics of how clean the combustion chamber is after running e85.

I've run it on road trips with the intention of doing a tune up in a tank full.

 

[Grendel]

Is that for the current Gen with dfm? I haven’t found any reliable information on it. Other than programming might be expensive.

Is that for the current Gen with dfm? I haven’t found any reliable information on it. Other than programming might be expensive.

Done it in an L83. <-- tuning only.

Cam and lifters, plus tuning in an LT1

Tuning is expensive, especially if the ECM/TCM is encrypted.

 

[Hubbler]

it won't help the intake, but if you run a tank of e85 thru it here and there on long road trips, that will clean out the cylinders. Letting a truck sit around with e85 can cause issues, but I've seen pics of how clean the combustion chamber is after running e85.

I've run it on road trips with the intention of doing a tune up in a tank full.

You've done this in the current t1xx, l84/l87 engines? These weren't cal'd nor cert'd for e85 use is why I ask.

 

[Aggie06]

Latest update. Haven’t driven much which is the norm this time of year.

The catch can collected 13 mls over 804 mile since last checked mid-January. Contents were a little milkier this time. I suspect it’s from water vapor due to wild swings in temp and humidity.

Oil level looked a quart low yesterday. Need to park on level ground and verify.

 

[gmcxt]

I have seen quite a few stuck collapsed and non locking lifters in the past few months. One poor customer needed a transmission. I put in a rebuilt unit on Friday and he had a lifter die on Saturday. $8000 in repairs between the two jobs.

I've been looking into this companies products. At this point I have worked on so many of these I will not buy a new Chevy and I'm a Chevy guys!

AFM/DFM Disabler - Range Technology

AFM Disabler and DFM Disabler for GM car, truck and suv

www.rangetechnology.com

 

[Aggie06]

Yeah, that sucks. What year and was his transmission an 8 spd? A guy in a Facebook group shared a video of his 5.3 with a lifter dying. It sounded like a old Diesel engine running.


I’m not going to be shocked if mine eats a lifter, but it’s not necessarily guaranteed. I have a slight tick, but that’s been since new.

 

[gmcxt]

Was a 6L80E TCC shudder and slipped in 5th.

 

[Aggie06]

Mine has the 8L90. It’s prone to shudder on cold mornings. Anecdotally, I’ve seen people claim the auto start/stop leads to an early death.

 

[gmcxt]

And this is the issue. ... The intake lifter is collapsed on this truck I'm working on today. So when the intake valve cannot open you create a negative pressure in the combustion chamber when the poison moves downwards on the intake stroke. When is should be taking a large breath in is instead confronted with a choking type scenario. Just put your hands over your mouth and nose and take a HARD breath. That volume change, as the piston goes down, creates vacuum in r cylinder drawing oil past the oil rings. This pressure happens everytime the cylinder is deactivated. Both the intake and exhaust valves stay closed by way of a collapsible lifter. There is no way to get around this. If the valves stay open like normal and do not stay closed and then you simply turn off the injector(s) the engine "feels like" it has misfires.
The flat line between the two vertical lines is zero pressure (absolute atmospheric pressure in the exhaust). If you have used pressure transducers this picture says Soo much. The curved line to the right of the flat area is about 20inhg in the the bottom The one to the l dt is also about 20i hg but that is because it would be the power stroke but there is no spark plug as my transducer is installed instead. TOP picture of both lifters disabled that better shows every time the piston goes down (twice/720* or 4 strokes) there is about 20inhg in the cylinder.
Just look at all the oil on the plug and in the cylinder from having a misfire for a few miles!
Cliff notes: buy the disabler that 1MPG is not worth the cost!

 

[gmcxt]

if you didn't know the head has to come off to do lifters on GEN 3+ SBCs.

 

[Aggie06]

Was that a 5.3 or 6.2?

 

[gmcxt]

2015 5.3L GDI

 

[Aggie06]

Stolen from Facebook. It was a 2019 5.3 with DFM.

 

[Aggie06]

Changed the oil today. It was around 5904 miles on the duration. Capacity at change is 8 qts with the filter. I collected just shy of 7 qts after draining the old filter. So, it’s burning around a qt at 6k miles. During that duration I collected around 80 mls in the catch can.

Did the MOA treatment again today. Will continue to track this.

 

[Aggie06]

Sitting at 56k miles now. Did an oil change yesterday and ended up catching around 6.5 qts, so it burned about 1.5 qts over 6900 miles. The catch can caught 83 mls during that period, so it’s pretty similar to the last oil change.

 

[SwordfishZ71]

As a data point to add to this.

I’m at 72k miles on my 5.3 l84 DFM 19 Silverado. I would burn about 1 quart between oil changes to at 5k intervals
Since new if I recall correctly. I tuned OFF DFM with superchips tuner about 2 oil changes ago. (10k ishh miles ago) I haven’t Burned a drop that I can notice since then after Tuning off DFM. It was the best investment.

As a reference I used this

Superchips 2847-S Superchips Flashpaq ECM MOD

The much-anticipated Flashpaq tuning with ECM Mod for 2019-2022 Silverado and Sierra is finally here! Available for 5.3L and 6.2L applications Flashpaq tuning offers up to an additional 45-horsepower!* The all-new GM Flashpaq performance programmer (PN 2847-S) comes pre-loaded with tunes...

www.holley.com

 

[Aggie06]

Bumping this. I changed my oil around 67500 miles today. I’m still burning around 2 qts every 6k miles. I was around 20% on the oil life monitor.
I haven’t done anything about turning off the DFM.

The catch can had 67 mls of oil in it over that period.

 

[Mattygwheeler]

What is your gas milage like?

 

[Aggie06]

What is your gas milage like?

That’s the lifetime average. My truck also has 285/70R17 10 ply tires, so that kills it some. As does the stop and go driving I do all summer. Highway, I can get close to 20 if I keep it below 75.

 

[gmcxt]

2qts in 6000 miles in the realm of normal.

AFM exists to give you a little fuel mileage increase and reduces tail pipe emissions. Let's say a lifter fails, it doesn't spin and eat your cam, it just gets locked collapsed. It's $3000-$4000 to replace all the lifter. Since the system is mostly for fuel mileage gains, you could rationalize that your fuel cost that you're tracking will suddenly rise from $11403 to $15403 because of ana associated maintenance issue. Suddenly the real world economics of the system falls into a trap. These parts will fail. Better get a tuner before its too late...