The 6.4L Hemi (392) is the big brother to the 5.7 Hemi. Introduced in 2011, it powers the Ram 2500/3500 HD trucks, Dodge Charger & Challenger Scat Pack, Jeep Grand Cherokee SRT, and Dodge Durango SRT.
The 6.4 is strong and reliable, but like other Hemis, it suffers from lifter/camshaft failures (“Hemi tick”), exhaust manifold bolt issues, and MDS cylinder deactivation problems.
At DK Auto & Diesel Service in Magnolia, TX, we repair and upgrade 6.4 Hemis for work trucks, muscle cars, and Jeeps.
Common 6.4 Hemi Problems & Symptoms
1. Lifter & Camshaft Failure (“Hemi Tick”)
• Symptoms: ticking noise at idle, worsening over time, misfires under load
• Causes: lifter roller seizure → wipes cam lobes
• Fixes: lifter & camshaft replacement with updated parts, MDS delete for longevity
2. MDS (Multi-Displacement System) Issues
• Symptoms: misfires, poor fuel economy, lifter collapse on deactivated cylinders
• Causes: MDS solenoid or lifter problems
• Fixes: disable MDS via tuning, replace faulty lifters/solenoids
3. Exhaust Manifold Bolt Failures
• Symptoms: ticking noise at cold start, exhaust leak odor, loss of power
• Causes: warped manifold → bolt breakage
• Fixes: replace bolts/studs, resurface or replace manifolds
4. Oil Consumption
• Symptoms: frequent low-oil warnings, blue smoke under load
• Causes: ring wear, PCV issues, high-mileage valve guide wear
• Fixes: piston ring service, PCV replacement, oil catch can install
5. Cooling System & Heat Soak Issues
• Symptoms: high engine temps under heavy load, heat soak after shutdown
• Causes: tight engine bay packaging in cars, heavy towing in trucks
• Fixes: upgraded radiators, thermostats, and oil coolers
How DK Auto & Diesel Fixes the 6.4 Hemi
- Lifter & camshaft replacements (Hemi tick repair)
- MDS deletes & tuning
- Exhaust manifold stud repairs
- Oil consumption diagnosis & repairs
- Cooling upgrades for heavy-duty towing & performance builds
- Preventive maintenance packages
Schedule Your 6.4L Hemi Diagnostic in Magnolia, TX
If your 6.4 Hemi is ticking, leaking, or burning oil, bring it to DK Auto & Diesel Service for expert repair and upgrades.
Serving Magnolia, Montgomery, Conroe, The Woodlands, Tomball, Willis, and Spring.
Book a Hemi Diagnostic Today
FAQ About the 6.4 Hemi
Is the 6.4 Hemi reliable?
Yes, it’s more durable than the 5.7, but lifter & camshaft failures are still a known weak point.
How long will the 6.4 last?
Many last 200k+ miles with proper maintenance. Fleet Ram HD trucks often push past 300k.
Should I disable MDS?
For longevity, many owners do — especially in Ram trucks. It helps prevent lifter collapse.
