2022 3500 HO - P2459 Dealer Replacing Rocker Arms

[Diller]

No modifications to the drivetrain. I use HSS EDT in every fill up since new. I get fuel from 2 or 3 different places. All at the "big rig" pumps.

I have a scan tool that I can get some data logs on however I am trying to avoid driving the truck until the work is complete.

Hopefully I'll have some more answers for what test was done and what was found in the next day or so from the technician.

 

[Scottly]

Something is strange here. The code was set because the ECU is detecting frequent DPF regenerations. This typically happens because the vehicle is lacking longer cruises to effectively run a regeneration cycle. Based on your reported typical drive cycles, this isn't the issue.

What else can cause this issue? I'm not seeing a connection between rocker arms and the high frequency of regens.

For the regen to occur, the exhaust has to develop a lot of heat. To do that, the injectors are fired an additional time so that raw fuel blows out into the exhaust. If the exhaust vales don't open enough, not enough of that fuel goes out. It explains the high aluminum content as the fuel remains in the cylinder and washes the oil off the cylinders and causes higher wear on the pistons.

This is all theory...YMMV

 

[BossHogg]

For the regen to occur, the exhaust has to develop a lot of heat. To do that, the injectors are fired an additional time so that raw fuel blows out into the exhaust. If the exhaust vales don't open enough, not enough of that fuel goes out. It explains the high aluminum content as the fuel remains in the cylinder and washes the oil off the cylinders and causes higher wear on the pistons.

This is all theory...YMMV

I'm anxious to hear the end cause. It seems to me if the rockers were the root cause, then wouldn't this issue be widespread?

I did some internet searches and it seems this issue is discussed a few times over several model years, but only on the HO version.

 

[crash68]

My understanding is the pressure is an actual sensor. It’s the temperature that is a calculation.

Unless something has changed on the Cummins within the last model year or two, both the oil temperature and pressure are calculated values. There is just a low oil pressure switch.
The EcoDiesel has the actual oil temperature but pressure is calculated.

 

[Diller]

Unless something has changed on the Cummins within the last model year or two, both the oil temperature and pressure are calculated values. There is just a low oil pressure switch.
The EcoDiesel has the actual oil temperature but pressure is calculated.

Learn something new every day.

I thought I would finally have a truck where I didn't need a set of analog gauges on the A pillar but I guess it may be on the way lol.

 

[Dusty]

That's strange, I have never not been given paperwork of some kind when I've had any of my vehicles worked on at an FCA dealership in the past 15 years including warranty work and I've always had to sign paperwork when I was given the keys...

You won't get a copy of the work order when the repair is continued for parts on order. The work order is given to the owner after the all work has been completed and closed out.

I believe the OP said they rescheduled it for awaiting parts.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33-gallon fuel tank, factory dual exhaust, 18” wheels. Build Date: 3 June 2018. Now at 87707 miles.

 

[bigblock_doc]

There are only two rockers per cyl. with a bridge connecting two valves to one rocker.

 

[jacob302]

The truck is generating too much soot from the valves not opening properly and letting in enough air for the fuel (too rich).

The DPF can only process a certain amount of soot after that it needs to regen. Too much soot is what causes too frequent regen which causes a code to be set even if driven mostly on the highway. The rich air : fuel mix could be due to the rocker arm wearing a hole where the push rods touch it and as a result the rocker arms not pushing on the valve sufficiently to open it as long or wide as it should. That is why your Iron is too high in the oil (rocker arm wear out). Your AL is high because the Iron shavings are circulating in the engine before it reaches the filter and causing abrasive wear of the softer AL components. The PCM update could be to modulate the EGR to be less aggressive and add less EGR into the oil.

I hope the rocker arm change out corrects this issue permanently. There are no good options for a diesel motor in a 3/4 ton+ truck than a Cummins ISB 6.7. This is my humble engineering opinion. I may be wrong.

 

[Diller]

The truck is generating too much soot from the valves not opening properly and letting in enough air for the fuel (too rich).

The DPF can only process a certain amount of soot after that it needs to regen. Too much soot is what causes too frequent regen which causes a code to be set even if driven mostly on the highway. The rich air : fuel mix could be due to the rocker arm wearing a hole where the push rods touch it and as a result the rocker arms not pushing on the valve sufficiently to open it as long or wide as it should. That is why your Iron is too high in the oil (rocker arm wear out). Your AL is high because the Iron shavings are circulating in the engine before it reaches the filter and causing abrasive wear of the softer AL components. The PCM update could be to modulate the EGR to be less aggressive and add less EGR into the oil.

I hope the rocker arm change out corrects this issue permanently. There are no good options for a diesel motor in a 3/4 ton+ truck than a Cummins ISB 6.7. This is my humble engineering opinion. I may be wrong.

Makes as much sense as any theory I have. The next question I will have is what would cause the rockers to wear so quickly in 20K miles? Is there an update to the rockers that would prevent the wear or is there another defective component that lead to this (plugged oil passage)?

Looks like the parts are scheduled to be in Monday at this point so hopefully the truck will get in the shop early next week.

 

[jacob302]

What is the actual build date of the truck ? You mentioned it was delivered in May 22, build must be a few months prior.