Service Bulletin - Under certain circumstances, after coming to a stop and engaging idle stop, the vehicle may not restart automatically due to excessive cylinder pressure and/or low cranking torque. Typically, the customer can immediately restart the vehicle by selecting Park and pressing the ENGINE START/STOP button.
full bulletin at NHTSA ↗2021 Honda Ridgeline engine problems
moderate 16 complaints filed with NHTSA · avg repair $3,100 · see engine across all vehicles →
Complaints
16
Recalls
0
Avg fix
$3,100
When does it fail?
Of the 16 engine complaints filed for the 2021 Honda Ridgeline, here's the actual mileage breakdown — failures cluster heaviest at 100,000-125,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
Is there a fix? Manufacturer service bulletins
The manufacturer has issued service bulletins covering engine on this vehicle — documented repair instructions, service campaigns, or warranty extensions sent to dealers. A TSB isn't a recall (it's not a free safety remedy), but it's the manufacturer acknowledging the issue and how to fix it.
Service Bulletin - MIL flashes and vehicle will not accelerate, low power. After cycling the ignition, the symptom does not return with no stored DTCs. This issue is more common in regions with cold weather (specifically near or below freezing temperatures). Usually after a long drive (around 2 hours) and accelerating while cornering.
full bulletin at NHTSA ↗Service Bulletin - The MIL flashes and vehicle will not accelerate, low power. After cycling the ignition, the symptom does not return with no stored DTCs. This issue is more common in regions with cold weather (specifically near or below freezing temperatures). Usually after a long drive (around 2 hours) and accelerating while cornering. Moisture accumulation in the intake manifold during long drives gets drawn into the combustion chamber while cornering, causing misfires.
full bulletin at NHTSA ↗Service Bulletin - Due to variations in the purge control solenoid valve spring, the valve wears unevenly and intermittently sticks. This may result in setting DTC P0441 (Evaporative Emission (EVAP) System Purge Flow Malfunction).
full bulletin at NHTSA ↗Service Bulletin - Under certain circumstances, after coming to a stop and the idle stop feature engages, the vehicle may not automatically restart. Typically, the customer can immediately restart the vehicle by selecting Park and pushing the ENGINE START/STOP button.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners describe two primary engine failure patterns in the 2021 Ridgeline. The first is a repeatable cold-weather limp-mode event: after 1–3+ hours of highway driving at 60–80 mph in temperatures below 32°F, the truck shakes, loses power to 2–3 cylinders, and the check engine light blinks when the driver decelerates then accelerates (typically at highway exits or merge ramps). The engine codes P0300, P0302, and P0303 appear briefly, then vanish after shutdown and restart—dealers find nothing and blame bad fuel or dismiss it as unfixable. Multiple owners across forums report identical conditions.
The second pattern is catastrophic: connecting rod bearing failure causing engine knock and eventual internal seizure. This occurs between 52,000 and 102,000 miles. One owner heard bottom-end knock at 2,500–3,500 rpm and had warranty replacement; another paid $11,000 for a new engine; a third had Honda deny coverage citing low oil levels detected during the failure itself. One owner also experienced complete freeway power loss in traffic—a serious safety event—with repair responsibility unclear.
Auto start/stop malfunctions round out the complaints: the engine fails to restart at idle after the system engages, requiring manual intervention. Dealer repairs for these have ranged from $800 starter replacement to unresolved cases where service bulletins apparently triggered the problem.
Same Honda Ridgeline engine reports on nearby years: 2018 · 2019 · 2020 · 2022 · 2023
Failure modes owners describe
Cold-weather limp mode after extended highway driving
Vehicle enters limp mode with blinking check engine light, rough idle, and severe loss of power (operating on 2-3 cylinders) after 1-3+ hours of highway driving followed by deceleration and acceleration in cold conditions (typically below 32°F). Condition clears after shutdown and restart. No stored codes found by dealers.
When: After 1-3+ hours highway driving at 60-80 mph, then exiting/decelerating followed by acceleration; outside temperatures near or below 32°F (one case at 10°F, one at 20°F). Mileage range: 1,800–10,100 miles.
Symptoms owners cite: Blinking check engine light; Vehicle shaking or sputtering; Severe loss of power, unresponsive to throttle; Limp mode activation; Engine running rough
Codes mentioned: P0300 (Random/multiple cylinder misfire), P0302 (Cylinder 2 misfire), P0303 (Cylinder 3 misfire)
Repairs/costs cited: Dealers initially blamed bad fuel; no permanent repair identified. One owner paid $1,700 without resolution described.
Connecting rod bearing failure
Lower bearing or connecting rod bearing failure causing severe engine knock, often progressing to catastrophic engine damage requiring full engine replacement. Occurs at varying mileages from 52,000 to 102,000 miles.
When: Mileage range 52,000–102,000 miles; one case at 2,500–3,500 rpm, another at 55 mph.
Symptoms owners cite: Loud knocking sound from engine compartment, especially at lower rpms; Engine sputtering; Loss of power (limp mode in one case); Check engine light illumination; Low oil level warning light (in at least one case)
Codes mentioned: P0300 (implied from misfire codes reported in related cases)
Repairs/costs cited: Requires engine replacement. Costs reported: $11,000 for new engine or $8,000 for used engine with 46k miles. One owner's repair was covered under warranty; another had warranty denied due to low oil level; some cases had Honda goodwill declining coverage.
Recalls/TSBs owners mention: One case involved Honda opening a case (EA25004); warranty extension campaign bulletin 1103A8 valve adjustment mentioned in one case. One owner reported recall 23-008 (Idle stop/start switch and PGM-FI update) prior to subsequent failure.
Auto start/stop system malfunction
Engine fails to automatically restart after auto stop/start feature engages at idle (e.g., at stoplight). Vehicle requires manual shift to park and restart button press to recover. Intermittent; may occur multiple times over weeks.
When: At stoplights or traffic lights; mileage range 50,500–60,000 miles.
Symptoms owners cite: Engine fails to restart automatically when releasing brake; Vehicle requires manual intervention (shift to park, press start button) to restart; Dashboard lights may go off briefly; Intermittent occurrence over repeated trips
Repairs/costs cited: One case: starter replaced for $800 after diagnostics identified bad starter. Another case: after dealer performed bulletin 23-008 and 1103A8, intermittent dashboard message 'Auto Engine Idle Stop Unavailable' persists; dealer unable to duplicate issue or identify root cause.
Recalls/TSBs owners mention: Recall 23-008 involves Idle stop/start switch update and PGM-FI update (Bulletin 23-008); Bulletin 1103A8 covers valve adjustment warranty extension campaign. Owner in one case suspects these bulletins introduced the problem.
Sudden complete engine loss of power on freeway
Engine suddenly loses all power while driving in traffic on freeway, forcing vehicle to coast to stop. Vehicle becomes unresponsive and coasts across multiple lanes.
When: While actively driving on freeway in heavy traffic; mileage context unclear but vehicle properly maintained.
Symptoms owners cite: Complete loss of engine power; Vehicle coasts to stop; No acceleration response
Repairs/costs cited: Vehicle towed to dealership; repair status and details not specified.
Recalls/TSBs owners mention: Case filed with Honda regarding safety concern; owner disputes that failure is due to lack of oil.
Acceleration failure without check engine light (low-mileage)
Vehicle fails to accelerate as intended when throttle depressed at low speeds; no warning lights present. Issue resolves after shutdown and restart.
When: At 22,000 miles; occurred while driving at 35 mph.
Symptoms owners cite: Vehicle fails to accelerate when throttle depressed; No warning lights illuminated; Issue resolves after shutdown and restart
Repairs/costs cited: Dealer suggested disengaging 'Econ Mode'; no root cause found. Failure persisted despite dealer visit.
Recalls/TSBs owners mention: Manufacturer made aware and filed claim; no recall or service bulletin mentioned.
Rod bearing damage at lower rpms
Knocking noise originating from engine bottom-end at 2,500–3,500 rpm indicates rod bearing damage. Detected early enough in one case for warranty coverage.
When: Detected at 53,000 miles in one case; another case began at 2,500–3,500 rpm with no mileage specified.
Symptoms owners cite: Knocking noise from bottom end / lower engine compartment; Noise audible at 2,500–3,500 rpm
Repairs/costs cited: Engine replacement required. One owner received warranty coverage; another noted his VIN excluded from recall for the same defect in nearby model years.
Recalls/TSBs owners mention: One case covered under warranty engine replacement; owner suggests recall may need expansion to wider range of VINs.
Synthesized from 16 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 4 most recent
I took my vehicle in to the dealer on 1/31/2023 to address recall 23-008 (Idle stop/start switch update). I had not had any problems with it , but I had them inspect it. They performed Bulletin 23-008, PGM-FI update. On 2/16/2023, after stopping at a stoplight, the engine shut down but it didn’t start back up when I tried to proceed. A message came up on the dash saying to put the vehicle in park…
The contact's husband owns a 2021 Honda Ridgeline. The contact stated that while her husband was driving 55 MPH, the vehicle went into LIMP Mode and made an abnormal knocking sound. The check engine warning light was illuminated. The driver was able to pull over to the side of the road. The vehicle was towed to the dealer, where the timing belt, the water pump, and the tensioner pulley were…
I have a 2021 Honda Ridgeline. It had a 3.5 liter V-6 with a 9 speed transmission. I was driving from Cincinnati to Cleveland on [XXX] Sunday [XXX]. It was about 25 degrees Fahrenheit outside and partly cloudy. After driving about 3 1/2 hours I exited the [XXX] and turned on to [XXX]. The on- ramp is a sharp right turn so you have to slow to around 25 mph or slower. When I gave my Honda gas to…
I began to hear a knocking noise at 2500 to 3500 rpms and I immediately took my vehicle to the dealer who confirmed rod bearing damage.
Had engine trouble with your 2021 Honda Ridgeline?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the engine problem on the 2021 Honda Ridgeline?
It's a documented issue but not catastrophic. 16 complaints have been filed. Repairs average $3,100 and most owners catch it before it causes a breakdown.
At what mileage does the engine typically fail?
Based on the 16 complaints filed, engine issues most often appear around 45,560 miles. Some report problems earlier; some make it well past 150,000 with no symptoms. Maintenance habits matter — vehicles that received timely fluid services and were not regularly overworked tend to last longer.
What does it cost to fix?
Independent shops typically charge around $3,100 for engine repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to engine?
No active recalls currently cover engine issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2021/Honda/Ridgeline.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.