From the legendary Cummins inline-6 engines in Ram HD trucks to the 3.0L EcoDiesel V6 in Ram 1500s and Jeeps, Dodge, Ram, and Jeep have built some of the most popular diesel trucks and SUVs in America.
These engines are known for power, towing capability, and durability — but they also have common problems, from VP44 pump failures in 24V Cummins to EcoDiesel oil cooler and emissions issues.
At DK Auto & Diesel Service in Magnolia, TX, we specialize in Cummins and EcoDiesel repairs, upgrades, and performance builds.
Dodge / Ram Cummins Diesel Engines
5.9L 12-Valve Cummins (1989–1998)
• Problems: KDP (killer dowel pin), weak transmissions (47RE), fuel leaks
• Fixes: KDP tab kit, HD transmission rebuilds, injection pump upgrades
5.9L 24-Valve Cummins (1998.5–2002, VP44 pump)
• Problems: VP44 injection pump failures, lift pump failures, electrical issues
• Fixes: lift pump upgrade (FASS/AirDog), VP44 replacement, ECM checks
5.9L Common Rail Cummins (2003–2007)
• Problems: injector failures (leaking/stuck open), weak lift pumps, turbo wear
• Fixes: injector replacement, CP3 pump upgrades, turbo rebuilds
6.7L Cummins (2007.5–present)
• Problems: DPF/EGR/DEF system failures, turbo actuator failures, head gasket issues, fuel pump failures (CP4 2019–2020)
• Fixes: updated emissions components, turbo actuator repairs, head studs, CP4 → CP3 conversion
Jeep / Ram EcoDiesel Engines
3.0L EcoDiesel V6 (2014–present, Ram 1500 / Jeep Grand Cherokee / Jeep Wrangler)
• Problems:
◦ Oil cooler failures → coolant/oil mixing
◦ Timing chain tensioner failures → catastrophic engine failure risk
◦ EGR cooler cracks → coolant loss, fire recalls
◦ Emissions system clogging → limp mode
• Fixes:
◦ Oil cooler replacement with updated design
◦ Timing chain service (preventive at high mileage)
◦ EGR cooler replacement (recall updates available)
◦ Emissions cleaning & updated calibration
How DK Auto & Diesel Fixes Dodge, Ram & Jeep Diesels
- VP44 pump & lift pump repairs (24V Cummins)
- Injector replacement & fuel system service (5.9 CR & 6.7 Cummins)
- CP4 → CP3 conversions (6.7 Cummins & EcoDiesel)
- KDP tab kits & reliability upgrades (12V Cummins)
- EcoDiesel oil cooler & timing chain repairs
- Emissions system service & cleaning (EGR/DPF/DEF)
- Turbo rebuilds & upgrades
Schedule Your Dodge, Ram, or Jeep Diesel Diagnostic in Magnolia, TX
If your Cummins or EcoDiesel-powered Ram/Jeep is suffering from fuel system problems, turbo issues, or emissions failures, trust DK Auto & Diesel Service for expert repair and upgrades.
Serving Magnolia, Montgomery, Conroe, The Woodlands, Tomball, Willis, and Spring.
Book a Diesel Diagnostic Today
FAQ About Dodge, Ram & Jeep Diesels
Is the 5.9 Cummins the best engine Dodge made?
- Many say yes — the 12V and early common-rail 5.9s are legendary for simplicity and reliability.
Is the EcoDiesel reliable?
- Newer versions are improved, but early EcoDiesels had major issues with oil coolers, EGR coolers, and timing chains.
What’s the biggest problem with the 6.7 Cummins?
- Emissions components (DPF/EGR) and the CP4 pump in some years. A CP3 conversion is the most popular fix.
