Certain vehicles listed above, may have a condition that could cause the engine coolant thermostat to open at a lower temperature than intended. If this condition were to occur, the Malfunction Indicator Lamp (Check Engine Light) will illuminate and a diagnostic trouble code will set. Additionally in some cases, the engine cooling fans may run after the engine is switched off. This special coverage covers the condition described above for a period of 15 years or 150,000 miles (240,000 km), whichever occurs first, from the date the vehicle was originally placed in service, regardless of ownership. For vehicles covered by Vehicle Service Contracts, all eligible claims with repair orders on or
full bulletin at NHTSA ↗2021 Chevrolet Blazer 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 Chevrolet Blazer, here's the actual mileage breakdown — failures cluster heaviest at 25,000-50,000 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.
What stands out
Among the 6 model years of Chevrolet Blazer in our records for engine problems, this one ranks #2 by owner-complaint volume.
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.
This service bulletin provides information on replacing the intake manifold when the engine is replaced after severe internal engine damage.
full bulletin at NHTSA ↗The service bulletin advises the tech of a normal transmission shift condition and the delay in throttle response when the throttle plate is opened rapidly and advises the customer that it is normal for the delay.
full bulletin at NHTSA ↗This service bulletin provides information to dealership personnel for new vehicles with less than 1,000 miles that may not pass California smog inspection or smog inspection in other states.
full bulletin at NHTSA ↗This service bulletin provides diagnostic repair information to correct an oil leak in the engine.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
Owners of 2021 Chevrolet Blazers report recurring radiator failures starting as early as 16,000 miles. Cracks develop in the radiator core, causing coolant leaks that are hard to spot because plastic catch pans underneath contain the fluid. Multiple owners have replaced the radiator twice or three times within 50,000 miles, with replacement costs ranging from $235 to $2,000 depending on warranty coverage. Dealers acknowledge seeing this problem frequently.
Fuel pump module failures occur early in ownership, with one owner experiencing three failures within three months of purchase. The vehicle stalls without warning and either won't restart or cranks excessively before starting. One failure was diagnosed via code P023F.
Camshaft carrier oil leaks stem from improper sealant application during manufacturing, per NHTSA bulletins. These leaks are difficult to detect and dealers have repaired them; one repair exceeded $7,500. A thermostat stuck open caused overheating and an abnormal fan condition. One purge pump failure disabled electrical features and triggered the check engine light.
Owners stress that coolant leaks and overheating can disable critical safety systems like power steering and ADAS, and pose fire risk if undetected.
Same Chevrolet Blazer engine reports on nearby years: 2020
Failure modes owners describe
Radiator cracking and coolant leaks
Radiators develop cracks in the core, typically in the upper front area, causing coolant to leak. Owners report multiple radiator replacements within short intervals (sometimes two or three within 50,000 miles). The plastic catch pan underneath makes leaks difficult to notice until significant damage occurs.
When: 16,000 to 95,000 miles; recurring within months of replacement
Symptoms owners cite: Coolant smell when parked with engine running; Visible coolant leaks; Engine overheating; Low coolant warning (if equipped); Power steering assist loss; Insufficient vehicle heat
Repairs/costs cited: Radiator replacement; one owner cited $235 out-of-warranty cost after first replacement was covered; another reported $2,000 estimate for out-of-warranty repair
Recalls/TSBs owners mention: Warranty coverage for early failures; GM partially reimbursed one owner for second replacement; dealers note this is a recurring issue
Fuel pump module failure
Fuel pump module fails, causing engine cranking and starting difficulty. Vehicle displays P023F diagnostic code. Dealer diagnosis and replacement performed under warranty.
When: 18,388 miles
Symptoms owners cite: Check engine light illumination; Engine cranks but does not start consistently; Vehicle stalls shortly after starting; Fuel gauge reading empty when tank is not
Codes mentioned: P023F
Repairs/costs cited: Fuel pump module replacement
Recalls/TSBs owners mention: Replaced under warranty; owner notes fuel pump module failure is a known issue with GM vehicles
Camshaft carrier oil leaks
Both camshaft carriers leak oil due to improper sealant application during manufacturing, per NHTSA bulletins 21-NA-240 and PIP5755. Leaks are difficult to detect visually and can worsen to create fire hazard.
When: 63,000 miles and unspecified mileages
Symptoms owners cite: Oil leaking from vehicle; Low-oil warning light (appears as condition worsens); Small oil droplets on ground
Repairs/costs cited: Camshaft carrier replacement; one owner cited repair cost over $7,500; one owner's repair failed and independent mechanic found additional separation in transmission, oil cooler line, valve, and hoses
Recalls/TSBs owners mention: NHTSA bulletins 21-NA-240 and PIP5755 acknowledge improper sealant application; dealers confirmed and repaired defect
Thermostat stuck open
Thermostat becomes stuck, causing coolant circulation issues and engine overheating. Diagnosed at dealership but repair was not completed.
When: 95,000 miles
Symptoms owners cite: Coolant leak onto vehicle floor; Engine overheating; Abnormal engine noise; A/C system intermittently inoperable; Fan remains engaged approximately 10 minutes after engine shutdown
Repairs/costs cited: Thermostat replacement recommended but not performed by owner
Purge pump electrical failure
Purge pump fails, illuminating check engine light and disabling electrical features in the vehicle.
When: 36,000 miles
Symptoms owners cite: Check engine warning light illuminated; Electrical features inoperable
Repairs/costs cited: Purge pump replacement recommended
Recalls/TSBs owners mention: Manufacturer opened a case; repair not completed per narrative
Fuel pump module recurring failure
Fuel pump module fails repeatedly within short intervals. Vehicle stalls without warning and cannot be restarted reliably. Owner reports three failures within three months of initial purchase.
When: Shortly after December 9, 2021 purchase (failures on December 16, 2021; January 26, 2022; February 19, 2022)
Symptoms owners cite: Vehicle comes to complete stop without warning; Fuel tank gauge reads empty; Engine will not start or starts intermittently
Repairs/costs cited: Fuel pump replacement
Synthesized from 16 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 3 most recent
Radiator failure caused power steering assist to not function properly and insufficient vehicle heat function. Engine electric fan would run continuously after vehicle shutdown.
On [XXX], I was driving my Blazer up to our local Museum to grab some information. The Museum is about a mile and a half from my house. When I had left my house, the car was driving like normal. I pulled into a parking spot at the Museum, and I went to shut the vehicle off, and I thought maybe the check engine light had come on but wasn't completely paying attention to the dash. About 10 minutes…
The contact owns a 2021 Chevrolet Blazer. The contact stated that the check engine warning light was illuminated. The contact was unable to use the electrical features in the vehicle. The vehicle was taken to the local dealer, where it was diagnosed that the purge pump needed to be replaced. The vehicle was not repaired. The manufacturer was contacted and opened a case. The approximate failure…
Had engine trouble with your 2021 Chevrolet Blazer?
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 Chevrolet Blazer?
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 64,667 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/Chevrolet/Blazer.
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.