1985 Autocar — we work on any truck
If it runs diesel and needs help, we'll show up. Age is not a barrier — classic, vintage, or modern.
Mobile Ram HD Truck & Cummins Service
Ram & Cummins Truck Repair in Charleston, SC — 2500–5500, We Come to You.
On-site diagnostics and repair for Ram heavy-duty work trucks — 2500, 3500, 4500, and 5500 — with the 6.7L Cummins diesel or the 6.4L HEMI gas engine. We test fuel, emissions, front end, brakes, and driveability right where the truck is parked, so you get the real cause before an expensive part gets thrown at it.
- 6.7L Cummins diesel and 6.4L HEMI gas — 2500, 3500, 4500, 5500
- Commercial, work-truck, and fleet Rams — plus daily-driver HD trucks
- Charleston, North Charleston, Summerville, Goose Creek, Mount Pleasant
6.7L Cummins Diesel — Known Failure Points
The Cummins problems we chase down
CP4, lift pump & injectors
CP4.2 failure and fuel contamination, weak lift pump supply pressure, and injector wear confirmed with supply, rail, return, and leak-off testing before a full fuel job.
DPF, DEF & EGR derate
Failed regens, DEF quality and dosing codes, EGR cooler and valve faults, NOx sensors, and speed derates diagnosed to clear limp mode and keep the truck moving.
VGT turbo actuator
Holset variable-geometry turbo actuator faults, sticking vanes, and boost or overboost codes traced before you replace the turbo.
Grid heater & hard start
Grid heater and intake heater faults, cold-start trouble, hard start, and crank/no-start complaints tested with live data before condemning parts.
6.4L HEMI Gas & HD Front End
Gas 2500/3500 and solid-axle chassis work
Exhaust manifold bolts
The 6.4L HEMI is known for broken exhaust manifold bolts and the tick that follows. We confirm it and lay out the fix on your 2500 or 3500 gas Ram.
MDS lifter tick & misfires
MDS lifter noise, collapsed lifters, and cylinder misfires diagnosed with live data and cylinder testing before tearing into the top end.
General driveability
Rough idle, stalling, check-engine lights, and power complaints on the 6.4L HEMI worked systematically so you fix the actual fault.
Death wobble & front end
Ram HD runs a solid front axle. We diagnose death wobble and steering complaints at the source — track bar, ball joints, tie rods, and steering damper — instead of guessing.
Ram Work-Truck Services
General repair and maintenance we do on Ram 2500 and up
Diagnostics & scan
Full-system scan, live data, and targeted circuit testing to pin down check-engine, ABS, and driveability faults on Cummins and HEMI Rams.
Front end, ball joints & track bar
Solid-axle front-end work — ball joints, track bar, tie rods, and death-wobble diagnosis on Ram HD trucks.
Steering & alignment-related
Steering gear, damper, linkage, and wander complaints diagnosed and corrected so the truck tracks straight.
Wheel bearings & hubs
Front and rear wheel bearings, unit hubs, and noise or play checked and replaced on HD Rams.
Brakes
Pads, rotors, calipers, hydraulics, and brake complaints handled on 2500 through 5500 work trucks.
Oil changes & scheduled PM
Cummins and HEMI oil changes, filters, fluids, and scheduled preventive maintenance — single trucks or full fleet PM programs.
Suspension
Shocks, springs, bushings, control arms, and load-related suspension issues on heavy-duty Rams.
Electrical & charging
Batteries, alternators, starters, grounds, wiring, and parasitic-draw or no-start electrical faults tested at the truck.
A/C, heat & cooling
A/C and heat performance plus cooling-system diagnosis — thermostats, water pumps, fans, and overheating on Cummins and HEMI Rams.
Test Before You Replace
Ram fuel, emissions, and front-end parts are expensive — verify first
A CP4 job, a set of injectors, or a turbo actuator on a 6.7L Cummins is real money, and a CP4 failure that contaminates the whole fuel system is worse. Broken HEMI manifold bolts and a solid-axle death wobble both get "fixed" over and over when the real cause was never confirmed. Replacing parts on a code alone is how people spend twice.
Lowcountry Diagnostics brings the diagnostics to your Ram and works the fault in order — fuel pressure and injector balance, emissions and turbo data, or steering and front-end play — so you know exactly what failed and what it takes to put it right. We focus on three-quarter-ton and up commercial and work trucks, gas and diesel.
Why fleets & owners call us
- Mobile service where the truck is sitting
- Testing before parts replacement
- Gas and diesel Ram HD, 2500 and up
- Clear written findings and next steps
- 24/7 Charleston-area availability
Need a Ram or Cummins tech in the Charleston area?
Call or text Lowcountry Diagnostics and we will come to the truck.
Common Ram & Cummins repair questions
Do you work on both the Cummins diesel and the 6.4L HEMI gas Ram HD trucks?
Yes. We cover Ram 2500 through 5500 with either the 6.7L Cummins diesel or the 6.4L HEMI gas engine — from work trucks and fleet units to daily drivers — on-site across the Charleston area. We focus on three-quarter-ton and up commercial and work trucks, gas and diesel.
Can you diagnose Ram death wobble and front-end problems?
Yes. Ram HD trucks use a solid front axle, and we diagnose death wobble and steering complaints at the source — track bar, ball joints, tie rods, wheel bearings, and the steering damper — instead of throwing parts at it.
Can you clear a Cummins DPF or DEF derate on-site?
Usually. We diagnose DPF, DEF, and EGR faults, failed regens, NOx and dosing codes, and speed derates where the truck sits so you can get the Cummins out of limp mode and back to work.
Do you come to my location and handle fleet PM on Ram trucks?
Yes. We are mobile and come to your yard, jobsite, terminal, home, or roadside across Charleston, North Charleston, Summerville, Goose Creek, and Mount Pleasant. We also run scheduled oil changes and preventive maintenance for Ram work trucks and mixed fleets. Call or text (843) 310-0995.
Request Ram & Cummins Service
Tell us your Ram model, engine, the symptom, and where the truck is. For urgent truck-down calls, calling or texting is fastest.
Truck in derate or down? Call or text (843) 310-0995 now.
Recent Repair Photos
A look at the repairs we make
Real field photos from Lowcountry Diagnostics — from engine diagnostics and electrical to hydraulic, HVAC, and heavy-duty truck service, handled on-site across the Charleston area.
Reviews