The 2019+ 6.7L Cummins Lifter & Cam Issue: Causes, Symptoms, What Fails, and How Owners Are Preventing Catastrophic Damage

If you own a 2019+ Ram 2500/3500 with the 6.7L Cummins, you’ve probably heard the stories: a faint tick at startup… then it gets louder… then the oil is contaminated with metal… and suddenly you’re staring at a cam/lifter job—or, in worst-case scenarios, an engine replacement bill that can land in the $25,000+ range.

This post breaks down what changed in 2019, what actually fails, what the warning signs look like, what Stellantis has said about oil viscosity, and what owners (and the aftermarket) are doing to reduce risk.

What Changed in 2019: Why 5th-Gen Cummins Valvetrain Is Different

From 1989–2018, Ram Cummins engines used a tappet-style valvetrain that required periodic valve lash adjustment but had a long reputation for durability. In 2019, Ram’s 6.7L Cummins valvetrain moved to self-adjusting hydraulic roller lifters to reduce noise and eliminate lash adjustment.

That “quiet + maintenance-free” win came with a new failure mode: when the roller/lifter assembly doesn’t get the lubrication and cooling it needs (especially early in the oil’s life at cold start, and later in the oil’s life after extended intervals), wear can accelerate at the roller-to-cam-lobe interface—and it only takes one failing lifter to contaminate the oil with metal.

What Typically Fails (and Why It Can Spiral)

1) Roller lifter design vulnerabilities

A common explanation in diesel technical media is that the hydraulic roller lifter design used in 2019+ Rams has multiple red flags—most notably roller construction and lubrication details—compared to other heavy-duty diesel lifter designs.

2) When the roller stops rolling

When a roller lifter begins to fail, the roller can seize (or effectively stop rolling smoothly). At that point, the cam lobe isn’t driving a roller anymore—it’s rubbing a sliding contact that generates friction, heat, and wear rapidly. That can gouge the cam and lifter, and the shrapnel goes straight into the oil.

3) Metal contamination is the “multiplier”

Once metal is circulating, the risk expands beyond the lifter/cam into other lubricated components. This is why owners often treat the noise as urgent: a lifter/cam event can become an “engine event” if the contamination isn’t caught early.

Save Your Rollers Now Before It's Too Late!

The Early Warning Signs Owners Report Most Often

The most common “first symptom” described across diesel media is:

Ticking/tapping at startup, often more noticeable when cold
A “typewriter” sound from the top end that may fade somewhat when warm
In some cases: misfire, rough running, codes, smoke, or power loss as damage progresses

If you have consistent ticking that’s growing louder, don’t drive it for weeks hoping it “goes away.” The earlier you diagnose, the better the odds you avoid collateral contamination.

Stellantis Oil Guidance Matters (and It’s in Writing)

One of the most concrete, “hard” pieces of supporting documentation in this whole topic is a Stellantis technical service bulletin that states:

15W-40 cannot be used in 2019+ 6.7L-equipped vehicles due to the new valvetrain design.
Using 15W-40 can cause deposits in the hydraulic valve lash adjusters, leading to undesirable noise and/or engine damage.

That bulletin also points owners back to the owner’s manual for exact recommendations and references using oils meeting specific standards.

Why this matters: even if oil viscosity is not the sole “root cause” of every failure, Stellantis is explicitly warning that viscosity choice can contribute to lifter/HLA problems via deposit formation and oil flow behavior.

Why Cold Starts and Long Intervals Get Mentioned So Often

Two themes show up repeatedly in technical explanations:

Cold-start flow: thicker oil flows more slowly at startup, and hydraulic systems rely on quick oil delivery to maintain proper function.
Deposit sensitivity: tight clearances + small passages can be more sensitive to deposits, especially if intervals are stretched or oil quality/spec is mismatched.

That doesn’t mean “short intervals guarantee safety.” But it does explain why many owners emphasize:

correct viscosity/spec
sane intervals
and paying attention to early noise

How People Diagnose It (and What Shops Look For)

A proper diagnosis can include:

Listening location and pattern (top-end tick vs exhaust leak vs injector noise)
Pulling the valve cover and inspecting valvetrain condition
Checking for abnormal lift/rocker motion (a worn cam lobe/lifter often shows reduced lift)
Oil filter inspection and/or used oil analysis (to detect abnormal wear metals early)

Many owners document the “starts as a tick” progression in forums and long threads, which is useful context but still anecdotal—treat it as pattern recognition, not lab data.

Prevention and Mitigation: What Owners Actually Do

1) Follow the 2019+ oil viscosity guidance

If your truck is 2019+, take the 15W-40 warning seriously. That’s not internet lore—it’s in a Stellantis bulletin.

2) Keep intervals realistic (especially for tow/idle duty)

Long drain intervals can increase deposit risk and reduce margin for error if a failure starts. This is why many owners of tow rigs choose more conservative intervals.

3) Consider early detection tools

Used oil analysis to track wear metals trend
Cutting filters open periodically
Addressing new or worsening tick quickly

4) Mechanical “bulletproofing” options exist (aftermarket)

A major reason the topic is so prominent is that multiple aftermarket solutions exist aimed at removing the hydraulic roller failure mode, including flat tappet conversion kits.

For example, Hamilton Cams markets a 2019+ flat tappet conversion kit specifically aimed at improving valvetrain durability.

DrivingLine also outlines two solution categories—solid-lifter conversions and flat tappet swaps—as paths owners choose to improve reliability (generally not cheap, and not a beginner DIY job).

What About Additives?

Some owners and shops use cleaning/friction-modifying additives when chasing ticking/noise associated with hydraulic components. In general, keep expectations grounded:

Additives can’t “un-wear” a damaged cam lobe or seized roller.
They’re best framed as preventive support or deposit-control help, not a repair for mechanical damage.

If an engine is already shedding metal, the priority is diagnosis—not pouring in a product and hoping for the best.

Save Your Roller Bearings Now Before It's Too Late!

FAQ

“Is every 2019+ Cummins guaranteed to fail?”

No. Failures are widely discussed, but not every truck experiences it. The risk conversation exists because the failure mode can be expensive and because many owners report early ticking patterns.

“What’s the first sign I should take seriously?”

A new, persistent top-end tick—especially one that’s growing or appearing more frequently—should be investigated sooner rather than later.

“Can wrong oil really matter?”

Stellantis explicitly warns against 15W-40 in 2019+ 6.7L Rams due to deposit formation in hydraulic lash adjusters leading to noise and/or engine damage.

“What’s the ‘permanent’ fix?”

Mechanical conversions (solid/flat tappet style) aim to remove the hydraulic roller lifter failure mode, but they’re costly and require serious labor.

Sources and Further Reading

DrivingLine: overview of the 2019+ hydraulic lifter issue, failure symptoms, and repair/solution paths
Stellantis TSB (NHTSA-hosted PDF): 15W-40 warning and deposit/HLA risk
Hamilton Cams: 2019+ flat tappet conversion kit (aftermarket mitigation approach)
Owner forum threads with firsthand stories (useful context, anecdotal)

The 6.7 Cummins Lifter Issues Revealed