The Powertrain Control/Emissions Diagnosis (PC/ED) manual has been revised for diagnosing electronic throttle bodies (ETBs). The ETC_ACT and ETC_DSD PIDs should not used to diagnose possible ETB concerns. The IDS has a limited refresh rate when reading these PIDs and cannot display quickly enough to validate a concern. The PCM automatically monitors these inputs more accurately and will set diagnostic trouble codes (DTCs) when appropriate. Using these PIDs for diagnostics will lead to inaccurate results and improper ETB replacements. If a concern is intermittent and no DTCs are present, refer to historical DTCs and the PC/ED, Section 3 No DTCs Present Index chart for further information.
full bulletin at NHTSA ↗2006 Mercury Mariner engine problems
moderate 4 complaints filed with NHTSA · avg repair $3,100 · see engine across all vehicles →
Complaints
4
Recalls
0
Avg fix
$3,100
When does it fail?
Of the 4 engine complaints filed for the 2006 Mercury Mariner, here's the actual mileage breakdown — failures cluster heaviest at 75,000-100,000 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
Of the 7 model years of Mercury Mariner we track for engine problems, this one has the fewest owner complaints on file (4).
No new NHTSA engine complaint has been filed on this vehicle in over 14 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.
FORD/MERCURY: MIL ON WITH DTC P0351-P0356; MULTIPLE COIL PRIMARY CIRCUIT. BUILT ON OR BEFORE 10/03/05. SOME VEHICLES EQUIPPED WITH A 3.0L ENGINE MAY EXHIBIT A MULFUNCTION INDICATOR LAMP (MIL) ON WITH TWO OR MORE DIAGNOSTIC TROUBLE CODES (DTCS) FOR COIL ON PLUG (COP) PRIMARY CIRCUIT FAULTS.
full bulletin at NHTSA ↗CAMSHAFT TICK NOISE - 3.0L 4V ENGINE ONLY.
full bulletin at NHTSA ↗POSSIBLE ENGINE DAMAGE - INSTALL SPECIAL SERVICE TOOLS PRIOR TO REMOVING CRANKSHAFT PULLEY BOLT - SERVICE TIP.
full bulletin at NHTSA ↗WDS COP KIT DIAGNOSTIC TIP - COIL ON PLUG (COP) IGNITION SYSTEMS - ENGINE MISFIRE OR ROUGH RUNNING.
full bulletin at NHTSA ↗Source: NHTSA manufacturer communications. Bring the bulletin number to your dealer or shop.
What owners are reporting 1 most recent
Tl* the contact owns a 2006 mercury mariner. While driving approximately 45 MPH, the vehicle stalled without warning. After restarting the vehicle, the instrument panel and gauge failed to operate. The failure occurred three times. On one occasion the vehicle would not start until several attempts were made. The vehicle was taken to an authorized dealer twice for the identical failure and they…
Had engine trouble with your 2006 Mercury Mariner?
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 2006 Mercury Mariner?
It's a documented issue but not catastrophic. 4 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 4 complaints filed, engine issues most often appear around 97,500 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/2006/Mercury/Mariner.
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.