In 2019–2020 Ram 2500 & 3500 trucks, the 6.7L Cummins received major updates for higher horsepower and torque. Unfortunately, these model years are some of the most problematic due to two major issues:
1. The switch from the Bosch CP3 fuel pump to the Bosch CP4.2 pump, which is known for catastrophic failure.
2. An increasing number of camshaft & lifter failures, leading to ticking noises, misfires, and in severe cases, full engine rebuilds.
Along with ongoing emissions and turbo actuator issues, this generation has developed a reputation for being costly to maintain without preventive action.
At DK Auto & Diesel Service in Magnolia, TX, we diagnose, repair, and upgrade 2019–2020 Cummins trucks for long-term reliability.
Common 2019–2020 6.7 Cummins Problems & Symptoms
1. CP4 Fuel Pump Failure
• Symptoms: sudden stalling, no start, metal shavings in fuel system, check engine light
• Causes: CP4 design flaw — poor lubrication and internal wear cause pump destruction
• Fixes: CP4 replacement, CP3 conversion (recall or aftermarket), full fuel system replacement if pump fails
2. Fuel System Contamination After Pump Failure
• Symptoms: misfires, no start, black smoke, injector failure after CP4 failure
• Causes: metal debris from pump failure spreads to injectors, fuel rail, and lines
• Fixes: full fuel system replacement (injectors, rails, lines, tank flush)
3. Camshaft & Lifter Failures
• Symptoms: ticking noise at idle, misfires under load, power loss, metal shavings in oil
• Causes: lifter roller seizure → wipes cam lobes; extended idling, high-load towing, and oiling limitations worsen the issue
• Fixes: camshaft and lifter replacement, upgraded components where available, strict oil maintenance with high-quality filters
4. Turbo Actuator & VGT Problems
• Symptoms: reduced boost, actuator-related codes, poor towing performance
• Causes: actuator motor failures or carbon sticking in turbo vanes
• Fixes: turbo actuator replacement, turbo rebuild, or upgrade
5. Emissions System Failures (DPF/DEF/EGR)
• Symptoms: check engine lights, frequent regen cycles, limp mode, poor mileage
• Causes: DEF heater and pump failures, NOx sensor failures, EGR valve clogging
• Fixes: DEF/EGR service and replacement, updated NOx sensors, full system diagnostics
6. Transmission Limitations (68RFE & Aisin AS69RC)
• Symptoms: slipping, harsh shifts, overheating, failure under heavy towing or high horsepower
• Causes: torque output exceeds stock transmission design
• Fixes: heavy-duty rebuilds, upgraded torque converters, valve body enhancements
How DK Auto & Diesel Fixes the 2019–2020 6.7 Cummins
- CP4 → CP3 conversions (recall or aftermarket kits)
- Full fuel system replacement after pump failure
- Camshaft & lifter replacements for ticking and valvetrain failure
- Turbo actuator repairs & turbo upgrades
- DEF/EGR/NOx sensor service and repairs
- Transmission rebuilds & upgrades for towing & power builds
- Preventive maintenance packages for fleet and owner-operator trucks
Schedule Your 2019–2020 Cummins Diagnostic in Magnolia, TX
If your 2019–2020 Ram 6.7 Cummins has fuel system issues, ticking from the valvetrain, or turbo/emissions warnings, bring it to DK Auto & Diesel Service for expert repair.
Serving Magnolia, Montgomery, Conroe, The Woodlands, Tomball, Willis, and Spring.
Book a Cummins Diagnostic Today
FAQ About the 2019–2020 Cummins
What’s the biggest problem with these years?
- The CP4 fuel pump — when it fails, it can destroy the entire fuel system. The camshaft & lifter failures are also becoming a well-known weak point.
Did Ram recall the CP4 pump?
- Yes — a recall offered a CP3 conversion on affected trucks.
Can the cam & lifter issue be prevented?
- Regular oil changes with high-quality filters help, but if ticking starts, a cam & lifter inspection is critical to avoid major damage.
