How To Prevent A Costly $25,000 Cummins Engine Failure In Your 2019+ Ram HD Truck

It wasn’t long before the hydraulic lifters became problematic—issues that could lead to camshaft failure or even complete engine damage if overlooked. The core of the problem lies not in the use of hydraulic lifters per se, but in their specific design. In this article, we’ll explore the design flaws associated with the hydraulic lifters found in the 2019 and newer 6.7L Cummins, identify symptoms of failure, and highlight two aftermarket solutions to prevent severe engine issues.

Why The Switch? Reduced Noise And Maintenance

The transition to self-adjusting hydraulic lifters for the 6.7L Cummins aimed to eliminate the need for valve lash adjustments and reduce noise from the valvetrain. Since the introduction of the 5.9L engine in 1989, Cummins utilized tappets, recognized for their reliability. Initially, the change to hydraulic lifters didn’t raise significant concerns; Ford had been successfully using hydraulic lifters in its Power Stroke engines since the mid-90s. However, for the 2019 and newer Rams, the design shortcomings of these hydraulic lifters have raised eyebrows.

Why They Fail

The design of the hydraulic lifters in the 2019 and newer 6.7L Cummins has several red flags. Firstly, they lack needle bearings in the roller, a component included in the Power Stroke models. Secondly, the tight tolerances in the roller assembly restrict proper lubrication and cooling from engine oil, compounded by inadequate oil passage sizes. Moreover, using thicker viscosity oils can hinder cold-start pressurization, leading to Ram’s Technical Service Bulletin that advises against using 15W-40 in the newer engines. Though using the proper oil may delay potential failures, it does not guarantee prevention.

An Added Point Of Potential Failure

If the absence of needle bearings and poor oiling don’t lead to lifter failure, there’s yet another lurking danger: the steel alignment dowel pin in the lower part of the lifter body. Analogous to the notorious dowel pin in the 12-valve 5.9L engines, this pin may loosen over time. If this happens, serious engine damage could follow. While this pin is essential to prevent lifter rotation, it also poses a risk of becoming a costly problem.

Symptoms Of Lifter Failure

Early indicators of hydraulic lifter failure are often noticed during initial start-up when the oil is still cool and not flowing optimally. This manifests as a ticking or tapping noise originating from the top of the engine. In certain 2019 and newer models, lifter tapping can occur within the first 10,000 miles. Remarkably, making it beyond 100,000 miles without lifter noise is seen as an achievement, a stark contrast to the consistent reliability of previous Cummins generations found in Ram trucks.

What Happens?

When lifters do not receive enough lubrication, they can collapse, causing the roller to overheat, blacken, and ultimately seize. Once the roller becomes stuck, it can no longer travel along the corresponding camshaft lobe, resulting in increased friction that damages both the roller and the camshaft. Additionally, the debris generated by the contact between the roller and cam contaminates the engine oil. If the engine sustains significant damage as a result of this failure and is outside of the manufacturer’s warranty, replacing the 6.7L Cummins engine can cost between $25,000 and $27,000 at a typical Ram dealership. It is important to note that using 15W-40 engine oil may void your warranty.

When you dddress it you find yourself with a new truck, with either the cab lifted and the engine removed or the front end disassembled for engine access. Although an in-frame repair is possible, it requires magnets to hold the lifters at the top of their bores while the camshaft is taken out of the block, and a trough must be inserted into the cam tunnel to catch the factory lifters. In-frame lifter repairs are not advisable for novice DIYers attempting this in their garage; if a lifter drops, the oil pan will also need to be removed.

Solution 1: Solid Lifter Conversion

To restore the reliability associated with Cummins, one can replace the hydraulic components of the factory lifters in favor of solid lifters. The Wagler Competition Products solid lifter conversion kit includes upgraded, appropriately sized Manton pushrods, OE adjustable rockers, and lifter spacers, with solid spacers replacing the hydraulic portions of the stock lifters. For those looking for an upgrade, Wagler also provides a Jesel lifter option if you prefer not to reuse the original lifter bodies, are seeking four-digit horsepower figures, or desire a higher-end choice. Additionally, one can incorporate a Wagler Stage 1 Cummins cam (minus the cam gear) for improved lift and duration.

Solution 2: Flat Tappet Swap

The flat tappet conversion kit from Hamilton Cams presents an alternative method for enhancing the valvetrain reliability in 2019 and later 6.7L Cummins engines, reverting back to a well-established design that has proven effective for 30 years. This comprehensive kit includes DLC coated tappets, Hamilton’s efficient 178/208 cam paired with the tappets, upgraded pushrods, and adjustable rocker arms. The rocker arms also feature DLC coated trunnions and enhanced oiling capabilities, leading to lower friction and improved hardness of crucial components while ensuring better lubrication and cooling for longevity.