Ram 5.7L HEMI: 10 Common Issues & Real Fixes

A complete owner’s guide for the 5.7L HEMI (2011–today): how the engine behaves, the most common problems you’ll actually see, how to confirm root causes, and the practical fixes. We also cover transmission health on heavy-duty models and when a BD 66RFE upgrade makes sense.

Jump to: #1 MDS Lifter/Cam • #2 Exhaust Manifold Studs • #3 Timing Chain/Tensioner • #4 Oil Consumption/PCV • #5 Plugs & Coils • #6 Intake/Runner Leaks • #7 Cooling System • #8 Oil Cooler Housing • #9 EVAP/Purge Valve • #10 Transmission Health

1) “HEMI Tick”: MDS Lifter & Cam Lobe Wear

A rhythmic tick (often warm) with misfire under load can point to a collapsing MDS lifter or a wiped cam lobe. The tick may begin subtle and grow with mileage. Confirm: borescope through lifter valley (where possible), misfire counters, and metal in oil/filter. Fix: replace affected lifters and cam as a set, refresh trays, use correct oil viscosity/spec, and avoid extended low-RPM lugging that keeps MDS active for long periods.

2) Broken Exhaust Manifold Studs & Warped Manifolds

Cold-start tick that fades warm, exhaust odor in the bay, slower spool on grades—classic signs. Heat cycling and thin flanges lead to stud breakage. Confirm: feel for leaks at the head, soot tracks, broken rear studs (common). Fix: manifold replacement or machine/plane, new gaskets, longer high-temp studs, and proper torque sequence with re-torque after a heat cycle.

3) Timing Chain, Guide & Tensioner Wear

Start-up rattle, cam/correlation codes, lazy low-end torque can point to chain stretch or a tensioner that bleeds down. Confirm: scan data (cam/crank variance), mechanical inspection. Fix: full timing set (chain, guides, tensioner), fresh seals; use approved oil and reasonable change intervals—dirty or thin oil accelerates wear.

4) Oil Consumption & PCV/Inlet Oiling

Blue smoke on start or high consumption between changes? PCV plumbing and ring condition matter. Confirm: PCV function test, borescope for carbon, leakdown if severe. Fix: renew PCV valve/hoses, ensure correct oil spec, address ring/cylinder issues if confirmed; keep the intake tract and throttle body clean to stabilize trims.

5) Spark Plug & Coil Maintenance (16 Plugs on Early Years)

Random high-load misfires or a rough idle are often simple: plugs gapped wide, aged coils, or moisture intrusion. Early 5.7Ls use 16 plugs—maintenance matters. Fix: replace with correct heat range/gap, inspect coil boots, and clear adaptives after repair.

6) Intake Manifold Runner & Air Leaks

Hesitation, whistling, or idle wander can trace to runner flap faults or gasket leaks. Confirm: smoke test the intake, monitor short/long-term trims, and check runner control faults. Fix: replace runner assemblies or gaskets, verify throttle body cleanliness and relearn idle if required.

7) Cooling System: Water Pump, Thermostat & Hoses

Weeping at the pump, creeping temps when towing, or heater performance swings point to cooling wear. Fix: quality pump/thermostat, cap, and hose refresh; ensure air is purged after service. Keep external radiator/trans cooler fins clean.

8) Oil Cooler / Filter Housing Leaks

Oil in the V of the block or on top of the transmission bellhousing? The filter/cooler housing can seep at seals or crack. Fix: upgraded housing or new seals, careful torque, and fresh O-rings. Clean the area and re-inspect after a few heat cycles.

9) EVAP Purge Valve & Rough Idle / Hard Start

A stuck purge can flood the intake with fuel vapors, causing hard warm starts and idle stumble. Confirm: purge duty cycle/command vs. flow, smoke test for leaks. Fix: replace purge valve, inspect lines and gas cap seal; clear trims and re-road test.

10) Transmission Heat & Shift Quality (545RFE / 66RFE / 8HP)

Hunting, shudder, or delayed lockup often trace to fluid age, cooler flow, or strategy—not just “engine problems.” Heavy-use 2500/3500 HEMI trucks with the 66RFE especially benefit from hardware updates that protect the OD clutches and valve body.

Why BD for Ram Gas Trucks

We focus on fixes that solve repeat failures in real-world use—towing, heat, and time. BD’s growing gas lineup (like the 66RFE RoadMaster) adds line pressure where it counts, improves cooling capacity, and pairs with a matched converter to keep lockup stable and shifts clean.

Always verify fitment, torque specs, and service procedures in the vehicle service manual and the product’s installation instructions. Keep emissions equipment intact and compliant. If in doubt, consult a qualified technician.