2020 Mercedes-Benz OH 1621

The 2020 Mercedes-Benz OH 1621 is a bus chassis known for its robust build and suitability for various public transportation applications. While specific horsepower and torque figures may vary depending on regional configurations and factory settings, these chassis are generally equipped with a Mercedes-Benz diesel engine designed for commercial use. Available engine options often include variants of the OM 900 series diesel engines. People generally appreciate the chassis’s reliability and durability, but may find parts availability and repair costs to be higher compared to more common bus chassis. This report outlines common issues and complaints specific to the 2020 OH 1621 chassis, categorized by major components.

Engine

OM 924 LA (likely Engine option)

• Fuel Injector Failure
  • Description/Symptoms: Engine misfires, rough idling, reduced power, increased fuel consumption, and black smoke from the exhaust. Diagnostic Trouble Codes (DTCs) related to fuel injector circuit malfunctions.
  • Solution: Diagnose the faulty injector(s) using diagnostic tools. Replace the faulty injector(s) with new or remanufactured units. Ensure proper calibration of the new injectors.
  • Estimated Cost to Fix: $200 - $800+ per injector depending on new/remanufactured and labor costs.
  • Recalls: None Found
• Turbocharger Failure
  • Description/Symptoms: Loss of power, excessive black smoke, whining noise from the turbocharger, and potentially oil leaks. DTCs related to turbocharger boost pressure.
  • Solution: Inspect the turbocharger for damage to the compressor or turbine wheels, as well as bearing wear. Replace the turbocharger assembly.
  • Estimated Cost to Fix: $1500 - $3500+ including labor.
  • Recalls: None Found
• Cooling System Leaks (Radiator/Hoses)
  • Description/Symptoms: Overheating, coolant loss, visible leaks around the radiator or hoses, and low coolant warning lights.
  • Solution: Pressure test the cooling system to locate leaks. Replace damaged hoses, radiator, or other leaking components. Ensure proper coolant mixture and bleed the system.
  • Estimated Cost to Fix: $100 - $1500+ depending on the component needing replacement.
  • Recalls: None Found

Transmission

ZF 6S 1000 BO (likely Transmission option)

• Gear Slippage
  • Description/Symptoms: Transmission slipping between gears, difficulty shifting, erratic shifting behavior, and associated DTCs.
  • Solution: Diagnose the root cause, which may involve worn clutch packs, malfunctioning valve body, or sensor issues. Overhaul or replace the transmission with a remanufactured unit.
  • Estimated Cost to Fix: $2500 - $6000+ depending on the severity of the damage and whether it is a repair or replacement.
  • Recalls: None Found
• Hard Shifting/Jerking
  • Description/Symptoms: Abrupt and harsh shifts between gears, jerking during acceleration or deceleration, and potential noises during shifting.
  • Solution: Inspect the transmission mounts, driveline components, and U-joints. Check and adjust the transmission control module (TCM) programming. May require valve body repair or replacement.
  • Estimated Cost to Fix: $200 - $2000+ depending on the components that need replacing.
  • Recalls: None Found
• Fluid Leaks
  • Description/Symptoms: Transmission fluid leaks from the seals, gaskets, or housing, leading to low fluid levels and potential damage.
  • Solution: Locate the source of the leak and replace the affected seals or gaskets. Inspect the transmission housing for cracks or damage. Ensure proper fluid level and type.
  • Estimated Cost to Fix: $100 - $800+ depending on the location and severity of the leak.
  • Recalls: None Found

Suspension

• Air Suspension System Leaks
  • Description/Symptoms: The vehicle sits unevenly, the air compressor runs constantly, hissing sounds from air leaks, and the suspension doesn’t maintain proper ride height.
  • Solution: Inspect air lines, air bags, and leveling valves for leaks or damage. Replace any leaking components and ensure proper system pressure.
  • Estimated Cost to Fix: $200 - $1000+ per air bag or leveling valve.
  • Recalls: None Found
• Worn Shocks/Struts
  • Description/Symptoms: Excessive bouncing, poor ride quality, reduced handling stability, and uneven tire wear.
  • Solution: Replace worn shocks and struts with new units. Consider upgrading to heavy-duty shocks for improved durability.
  • Estimated Cost to Fix: $200 - $800+ per axle.
  • Recalls: None Found

Electrical

• Faulty Instrument Cluster
  • Description/Symptoms: Inaccurate or non-functional gauges, warning lights that illuminate intermittently or constantly, and display issues.
  • Solution: Diagnose the instrument cluster using diagnostic tools. Repair or replace the faulty instrument cluster.
  • Estimated Cost to Fix: $300 - $1200+ for repair or replacement.
  • Recalls: None Found
• Sensor Failures (ABS, Speed, etc.)
  • Description/Symptoms: Malfunctioning ABS system, speedometer issues, engine performance problems, and related DTCs.
  • Solution: Identify the faulty sensor using diagnostic tools. Replace the defective sensor and clear the DTCs.
  • Estimated Cost to Fix: $100 - $500+ per sensor.
  • Recalls: None Found
• Wiring Harness Issues
  • Description/Symptoms: Intermittent electrical problems, short circuits, corrosion, and damaged wiring insulation.
  • Solution: Inspect the wiring harness for damage and repair or replace sections as needed. Ensure proper grounding and connections.
  • Estimated Cost to Fix: $100 - $1000+ depending on the extent of the damage.
  • Recalls: None Found

Exterior

• Door Issues (Hinges, Latches)
  • Description/Symptoms: Doors that are difficult to open or close, sagging doors, and malfunctioning latches or locking mechanisms.
  • Solution: Adjust or replace door hinges, latches, and locking mechanisms. Lubricate moving parts.
  • Estimated Cost to Fix: $50 - $500+ per door depending on the parts needing replacement.
  • Recalls: None Found
• Lighting Issues (Headlights, Taillights)
  • Description/Symptoms: Dim or non-functional headlights or taillights, flickering lights, and damaged lenses.
  • Solution: Replace bulbs, lenses, or entire light assemblies as needed. Check wiring and connections.
  • Estimated Cost to Fix: $20 - $300+ per light depending on the complexity of the system.
  • Recalls: None Found

Interior

• HVAC System Malfunctions
  • Description/Symptoms: Inadequate heating or cooling, strange odors, noisy blower motor, and malfunctioning controls.
  • Solution: Diagnose the HVAC system for leaks, blockages, or component failures. Repair or replace the faulty components, such as the compressor, condenser, evaporator, or blower motor.
  • Estimated Cost to Fix: $100 - $1500+ depending on the failing component.
  • Recalls: None Found
• Seat Damage
  • Description/Symptoms: Broken seat frames, worn seat belts, malfunctioning adjustment mechanisms.
  • Solution: Repair or replace damaged seat components. Ensure proper functioning of seat belts and adjustment mechanisms.
  • Estimated Cost to Fix: $50 - $500+ per seat.
  • Recalls: None Found

Summary

The 2020 Mercedes-Benz OH 1621 bus chassis, while known for its robust construction, can experience a range of issues. Engine issues such as fuel injector and turbocharger failures can lead to significant performance problems and repair costs. Transmission issues, particularly with the ZF 6S 1000 BO, can cause shifting problems and necessitate costly repairs. Suspension and electrical problems also contribute to the overall maintenance burden. While some issues may be minor and relatively inexpensive to fix, others, such as major transmission or engine repairs, can be quite costly. These vehicles can be costly to maintain, especially when they are a bus or coach that drives for many hours a day. Potential buyers should carefully inspect the chassis and consider its maintenance history before purchase.