The 2021 Honda Ridgeline with its J35 V6 is generally reliable, but suffers from a surprising number of transmission-related issues and some premature engine failures—unusual for modern Honda products but documented across the Gen 3 platform.
Transmission Oil Cooler Failure
Occasional · high severityTypical onset: 40,000-80,000 mi
Symptoms: Transmission fluid mixing with coolant (strawberry milkshake fluid), Overheating transmission or engine, Harsh shifting or slipping, Check engine light with P0710 or P0868 codes
Fix: Replace transmission oil cooler, flush both cooling system and transmission completely, sometimes requires transmission rebuild if contamination occurred. 8-12 hours labor if caught early, 20+ if transmission damaged.
Estimated cost: $1,200-$5,500
Premature Engine Bearing Failure / VCM-Related Damage
Rare · high severityTypical onset: 30,000-70,000 mi
Symptoms: Knocking or ticking from lower engine, Metal shavings in oil, Loss of oil pressure, Engine misfire or rough idle before catastrophic failure
Fix: Variable Cylinder Management (VCM) system can cause oil starvation to cylinder 1 and 4. Requires full engine rebuild or short block replacement. 18-25 hours labor for short block swap.
Estimated cost: $6,000-$9,500
Transmission Mount Failure
Common · medium severityTypical onset: 50,000-90,000 mi
Symptoms: Clunking when shifting from Park to Drive, Excessive vibration at idle, Visible sagging or torn rubber on mount, Harsh engagement into gear
Fix: Replace failed transmission mount, sometimes requires upper engine mount as well due to stress transfer. 2-3 hours labor.
Estimated cost: $350-$650
Fuel Injector Clogging / Fuel System Issues
Occasional · medium severityTypical onset: 60,000-100,000 mi
Symptoms: Rough idle or hesitation on acceleration, Misfires on multiple cylinders, Poor fuel economy, P0300 series misfire codes
Fix: Direct injection system prone to carbon buildup and injector fouling. Requires injector cleaning or replacement, sometimes walnut blasting intake valves. 4-6 hours labor for full service.
Estimated cost: $800-$1,800
Backup Camera Failure
Occasional · low severitySymptoms: Intermittent or complete loss of backup camera display, Distorted or grainy image, Guidelines not displaying correctly, System takes long time to engage when shifting to reverse
Fix: Often caused by moisture intrusion in tailgate camera assembly or display unit failure. Camera replacement is 1.5 hours, display unit is 2-3 hours. Honda issued recall for some units.
Estimated cost: $400-$1,200
9-Speed Automatic Transmission Harsh Shifting
Common · medium severityTypical onset: 20,000-60,000 mi
Symptoms: Harsh downshifts especially 3rd to 2nd, Hesitation or delay when accelerating from stop, Shuddering during light acceleration, Occasional flaring between gears
Fix: Software updates address some cases, but many require clutch pack replacement or valve body work. 6-10 hours labor for internal transmission work.
Estimated cost: $400-$3,500
Buy a 2021 if you find one with documented frequent transmission services and ideally with VCM disabled by previous owner—otherwise the engine risk is too high for a truck this new.
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.