2018 RAM 1500

3.6L V6 Pentastar4WDAUTOMATICgas
5-Year Cost of Ownership
$15,716 maintenance + known platform issues
~$3,143/yr · 260¢/mile equivalent · $6,012 maintenance + $9,004 expected platform issues
Compare this engine
vs
3.0L V6 EcoDiesel
vs
3.6L V6 Pentastar eTorque
vs
5.7L V8 Hemi eTorque
Common Problems & Known Issues

The 2018 Ram 1500 is the last year of the DS/DJ platform before the redesign. The 3.6L Pentastar is generally solid, but the 3.0L EcoDiesel and 5.7L Hemi both have documented catastrophic failures. Transmission issues span all engine options, with cooler and mount failures being signature problems.

3.0L EcoDiesel Catastrophic Engine Failure (EGR Cooler Clog Leading to Piston/Bearing Damage)

Occasional · high severity
Typical onset: 80,000-140,000 mi
Symptoms: Excessive oil consumption (quart per 1,000 mi or worse), White smoke on cold start, Check engine light with DPF/EGR codes, Sudden loss of power, knocking, complete failure
Fix: EGR cooler clogs with soot, then cracks and dumps coolant into cylinders, washing cylinder walls and scoring pistons. By the time it's diagnosed, you're looking at engine rebuild or replacement: pistons, rings, bearings, machine work, or short block. 25-35 hours labor for in-chassis rebuild, more for R&R if block needs to come out fully.
Estimated cost: $8,000-15,000

5.7L Hemi Lifter and Cam Failure (MDS-Related)

Common · high severity
Typical onset: 60,000-120,000 mi
Symptoms: Ticking or tapping noise on cold start that doesn't go away, Check engine light with multiple misfire codes, Loss of power, rough idle, Metal shavings in oil
Fix: The Multi-Displacement System (cylinder deactivation) causes lifter needle bearings to fail, which can wipe the camshaft. Once the cam is damaged, you're replacing cam, all lifters, possibly pushrods, and sometimes rocker arms. If caught early (just lifters), 8-12 hours. If cam is gone, 15-20 hours plus head work.
Estimated cost: $3,500-7,500

Transmission Oil Cooler Failure (Internal Contamination)

Common · high severity
Typical onset: 70,000-110,000 mi
Symptoms: Transmission slipping or harsh shifts, Milky or glittery transmission fluid, Overheating transmission temp warning, Complete transmission failure
Fix: The external cooler (integrated with radiator on some models or standalone) corrodes internally, allowing coolant and ATF to mix, which destroys clutches and valve body. If caught immediately, cooler replacement plus triple fluid flush is 4-6 hours. If driven after contamination, full transmission rebuild or replacement required: 10-15 hours.
Estimated cost: $800-1,200 (cooler only), $3,500-5,500 (full rebuild)

Transmission Mount Collapse (Rear Mount)

Common · medium severity
Typical onset: 50,000-90,000 mi
Symptoms: Clunk or bang when shifting from park to drive or reverse, Vibration at idle in gear, Visible sag or torn rubber on mount inspection
Fix: The rear transmission crossmember mount fails from heat and load cycles. Rubber separates or crushes. Replacement is straightforward: support transmission, unbolt mount, install new. 1.5-2.5 hours depending on exhaust routing and access.
Estimated cost: $250-450

Fuel System Issues (3.0L EcoDiesel - Filter Housing and Pump)

Occasional · medium severity
Typical onset: 60,000-100,000 mi
Symptoms: Hard starting, especially in cold weather, Loss of power under load, Check engine light with low fuel pressure codes, Fuel in oil (severe cases)
Fix: Diesel fuel filter housing cracks or seals fail, allowing air intrusion or fuel leakage. High-pressure fuel pump can also fail, contaminating oil with diesel. Filter housing replacement is 2-3 hours. Fuel pump replacement is 6-9 hours and requires fuel system priming and extensive diagnostic time.
Estimated cost: $400-800 (filter housing), $2,500-4,000 (fuel pump)

EVAP System and Fuel Tank Vent Valve Failures

Occasional · low severity
Symptoms: Check engine light with EVAP leak codes (P0456, P0457), Difficulty fueling (pump clicks off repeatedly), Fuel smell near tank or under vehicle
Fix: EVAP canister vent valve sticks or purge valve fails. Sometimes the tank vent valve itself needs replacement, which requires dropping the fuel tank. Vent valve alone: 1.5-2 hours. Tank drop for internal valve: 4-6 hours.
Estimated cost: $300-600 (vent valve), $800-1,400 (tank drop work)

Rear Differential Pinion Seal Leak

Occasional · low severity
Typical onset: 70,000-120,000 mi
Symptoms: Gear oil dripping from front of rear differential, Low diff fluid on inspection, Whining noise from rear axle if run low
Fix: Pinion seal hardens and leaks. Common on trucks that tow. Driveshaft removal, seal replacement, fresh fluid. 2-3 hours labor.
Estimated cost: $350-550
Owner tips
  • If buying a 3.0L EcoDiesel, have a pre-purchase borescope inspection done and verify EGR cooler recall (if applicable) was completed. Run full synthetic 5W-40 and monitor oil consumption religiously.
  • On 5.7L Hemis, switch to 0W-40 synthetic and do 5,000-mile oil changes max. Consider disabling MDS with a tuner if you keep it long-term—it's the root cause of lifter failures.
  • Flush transmission fluid every 50,000 miles and inspect cooler lines annually for corrosion. Catch cooler failure early and you save the transmission.
  • Check transmission mount on every oil change after 50k miles—it's a $200 part that prevents a $5,000 transmission replacement if ignored.
I'd buy a 3.6L V6 version used without hesitation, but walk away from high-mileage EcoDiesels and inspect any Hemi carefully for lifter tick—these engines can grenade expensively.
AI-assisted summary drawn from NHTSA recall data, our labor-times database, and platform knowledge. Not a substitute for a pre-purchase inspection on a specific vehicle.
520 jobs across 15 categories
Building an app?
Free API access to all this data — 50 requests/day, no card required.
Get an API key →
Run a shop?
Manage repairs, estimates, and customers with ShopBase — $249/mo, all features included. Built by the same team.
Try ShopBase →