This service bulletin provides information for maintenance cleaning of the fuel injectors and gasoline detergent additive.
full bulletin at NHTSA ↗2007 Chevrolet Trailblazer engine problems
severe 24 complaints filed with NHTSA · avg repair $3,100 · see engine across all vehicles →
Failure mileage
Complaints
24
Recalls
0
Avg fix
$3,100
2fires
When does it fail?
Of the 24 engine complaints filed for the 2007 Chevrolet Trailblazer, here's the actual mileage breakdown — failures cluster heaviest at 50,000-75,000 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
No new NHTSA engine complaint has been filed on this vehicle in over 12 years — the issue may be aging out of the active population.
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 bulletin provides information on identifying Non-GM Engine Calibrations for Gasoline Engines using the Tech 2 or GDS 2.
full bulletin at NHTSA ↗This service bulletin provides guidelines and diagnostic/repair information to technicians regarding vehicle engine oil consumption.
full bulletin at NHTSA ↗This service bulletin advises of a new fuel injection cleaner kit used for decarbonizing the intake valves to correct conditions of rough idle, Crank no start, extended crank or misfire, MIL with DTCs, and explains how Top Tier fuels should be used to reduce carbon build-up.
full bulletin at NHTSA ↗This service bulletin provides technicians with information to help identify the differences between what is considered a fluid leak, and what is considered fluid seepage.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
The failure pattern owners describe
The 2007 Chevrolet Trailblazer engine cluster shows persistent, widespread defects. Owners of the 5.3L V8 report excessive oil consumption—1 quart per 770–2000 miles—starting at low mileage, which GM dealerships initially dismissed as normal. Numerous owners describe secondary air injection system failures with melted relay connectors, creating fire hazards and battery drain problems.
Stalling without warning is the most frequent complaint, occurring at speeds ranging from idle to 50 mph, sometimes repeatedly, with multiple dealer attempts at diagnosis and repair failing to resolve it. Fuel gauge malfunctions affect vehicles from 27,000 miles onward, with gauges jumping from full to empty or displaying wildly inaccurate levels despite owner tracking. Some owners spent $600+ on repairs with no lasting fix.
Throttle body freezing causes unexpected acceleration; one replaced throttle body failed again. Engine fires are documented, with flames shooting from hoods and vehicles exploding with little warning. Additional issues include rough idle with heavy vibration despite component replacement, exhaust manifold leaks introducing carbon monoxide into cabins, and overheating caused by failed temperature sensors.
Most troubling: dealers and GM repeatedly deny problems or offer no resolution, leaving owners with safety hazards and mounting repair costs. Owner research reveals hundreds of similar complaints across forums with no confirmed factory fixes.
Same Chevrolet Trailblazer engine reports on nearby years: 2005 · 2006 · 2008
Failure modes owners describe
Excessive Oil Consumption
Engine burns oil at an abnormal rate, with owners reporting 1 quart per 770–2000 miles on a 5.3L V8 engine. Affected vehicles run in 4-cylinder mode during light load, causing piston rings and valve guides to leak oil into the cylinder. GM dealerships initially denied the issue as normal consumption; owners note this is widespread among 5.3L engines in half-tons and larger SUVs.
When: Low mileage (41,000 miles reported); develops within the first year of ownership despite regular maintenance
Symptoms owners cite: Oil level drops rapidly between service intervals; Oil burns off causing buildup; Damaged engine sensors and catalytic converter over time
Repairs/costs cited: Owners suggest piston ring and valve guide replacement or short-block engine swap; not addressed under warranty due to age
Recalls/TSBs owners mention: GM dealerships stated excessive consumption was normal; owner found no factory recall or TSB addressing the issue
Secondary Air Injection (SAI) System Failure
Air pump relay connector melts and shorts, causing the secondary air injection pump to fail. The fault creates a large current draw on the battery and poses both electrical drain and fire hazard risks.
When: Reported as very common issue with Trailblazer; timing not specified in narrative
Symptoms owners cite: Check engine light illumination; Abnormal fan/vacuum noise from engine area, especially after vehicle shut-off; Lights dimming and flickering while driving; Battery drains completely overnight; Vehicle fails to start; Melted relay connector
Codes mentioned: P2431
Repairs/costs cited: Air pump relay and secondary air injection pump replacement required; parts availability may delay repair
Recalls/TSBs owners mention: No recall or warranty coverage mentioned; repair shop identified it as very common issue warranting potential recall
Stalling Without Warning
Engine shuts down without warning while driving at various speeds (25–50 mph) or at complete stops. Many stalls are intermittent and undiagnosable; some occur after PCM replacement and transfer case calibration updates, suggesting a persistent electronic control issue.
When: Reported from 21,000 miles through 126,000 miles; intermittent occurrence makes prediction difficult
Symptoms owners cite: Engine dies with no warning lights or indication beforehand; Vehicle difficult to control after stall; Stall during vehicle operation at various speeds or at stops; Check engine light may illuminate after restart; Loss of power steering and braking assist while stalled
Repairs/costs cited: PCM replacement, transfer case calibration updates, and engine replacement attempted; stalling persists in multiple cases
Recalls/TSBs owners mention: GM and dealerships instructed owners to keep driving to allow fault code to set; dealership held vehicle 42 days unable to diagnose; no resolution provided
Fuel Gauge and Sender Malfunction
Fuel gauge rapidly drops from full to empty or vice versa, or displays inaccurate fuel levels. Gauge may rise and fall erratically on startup. Gas cap warning message appears intermittently. Affects vehicles as early as 27,000 miles; persists for months without resolution.
When: Starts around 27,000–31,000 miles; persists indefinitely despite owner tracking and maintenance
Symptoms owners cite: Gauge jumps from full to empty rapidly; Inaccurate fuel level display; Erratic gauge movement on startup; False gas cap warning messages
Repairs/costs cited: GM suggests wire harness replacement on top of gas tank, requiring 5-hour service; owners report $600+ spent with issue recurring
Recalls/TSBs owners mention: GM suggested wire harness replacement but owner expected to pay half cost; no recall issued despite owner finding 70+ complaints about same issue
Throttle Body Freezing and Unintended Acceleration
Throttle body becomes unresponsive or freezes, causing low initial power response followed by unexpected acceleration. Traction warning indicator illuminates. Replaced throttle body fails again; issue also manifests as engine continuing to accelerate after throttle is released.
When: Failure mileage 21,000 miles; recurrence at 35,950 miles
Symptoms owners cite: Low power response initially, then unexpected acceleration; Traction warning indicator illuminates and persists; Engine continues accelerating after throttle release
Repairs/costs cited: Throttle body replaced twice with recurrence
Engine Fire
Engine compartment fires occur with little warning, destroying vehicles. In one case, flames shot from hood approximately 10 minutes after hearing a loud pop. In another, smoke from under hood preceded complete vehicle explosion.
When: At 68,065 miles (one case) and at age 3 years (another case)
Symptoms owners cite: Loud pop from engine followed by flames in hood area; Smoke coming from under hood; Rapid fire spread resulting in vehicle destruction
Repairs/costs cited: Vehicles destroyed; one fire report filed
Recalls/TSBs owners mention: Manufacturer stated would take complaint but provided no further assistance
Engine Stall Due to Water Intrusion
Engine stalls without warning at highway speed due to water inside the engine.
When: 94,000 miles
Symptoms owners cite: Vehicle stalled at 30 mph without warning; Complete loss of power
Repairs/costs cited: Vehicle repaired after diagnosis of water in engine
Engine Overheating
Engine overheats due to temperature sensor failure. Dealer offered no assistance.
When: 96,000 miles with failure occurring between 96,000 and current 100,000 miles
Symptoms owners cite: Engine overheating
Repairs/costs cited: Issue not repaired
Recalls/TSBs owners mention: Dealer offered no assistance; manufacturer not notified
Exhaust Manifold Leak
Bolts on exhaust manifold break, causing exhaust gas to leak into the vehicle cabin. Creates carbon monoxide poisoning risk.
When: Not specified; mileage and timing unknown
Symptoms owners cite: Exhaust gas entering vehicle interior; Broken manifold bolts on left front and both rear sides of head
Rough Idle and Vibration
Vehicle vibrates heavily while idling and acts as if it is about to stall. After replacing engine mounts, spark plugs, coils, boots and performing intake flush and routine maintenance, issue persists. Owner reports numerous Trailblazers with same unresolved issue.
When: Not specified; ongoing condition
Symptoms owners cite: Heavy vibration while idling; Vehicle feels like it is about to stall while stopped in drive; Stalling hazard with children in vehicle
Repairs/costs cited: Engine mounts, spark plugs, coils, boots replaced; intake flush performed; issue unresolved
Synthesized from 24 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 2 most recent
While taking my kids to school this morning, the engine shutoff shut off with no indication at all. We were starting to slow down to turn the corner to head to the school when this incident occurred. We have had several components (battery, ignition switch, alternator, starter relay) changed out the fixed the engine light, but the engine continues to stall. I have seen over 500 other people with…
Tl* the contact owns a 2007 Chevrolet trailblazer. The contact stated that while driving at various speeds, the transmission would not shift gears properly and the vehicle jerked. The vehicle was taken to a dealer, who diagnosed that the throttle position sensor needed to be replaced. The vehicle was repaired. The manufacturer was notified of the failure. The approximate failure mileage was…
Had engine trouble with your 2007 Chevrolet Trailblazer?
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 2007 Chevrolet Trailblazer?
It's a meaningful issue. 24 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $3,100.
At what mileage does the engine typically fail?
Across the 20 complaints that reported odometer mileage, most engine failures cluster between 41,000 and 102,000 miles, with the median around 80,000. A quarter of owners report trouble before 41,000; a quarter make it past 102,000. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
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/2007/Chevrolet/Trailblazer.
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.