Various vehicles equipped with a 4.6L, 5.4L, 6.8L modular 3 valve engine built on or before 8-Jan-2016 may exhibit symptoms that may include upper end engine noise, rough running, misfire and/or engine damage. If diagnosis leads to only camshaft/camshaft roller follower(s) requiring replacement, replace all of the camshaft roller followers on both banks/cylinder heads with part number 3L3Z-6564-A, not just the faulty roller follower(s). When replacing the camshaft roller followers, refer to Workshop Manual (WSM), Section 303-01.
full bulletin at NHTSA ↗2008 Mercury Mountaineer 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
What stands out
Of the 4 model years of Mercury Mountaineer 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 15 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.
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 ↗FORD/MERCURY: SOME VEHICLES MAY EXHIBIT A NO CRANK, CRANK NO START, DRIVEABILITY SYMPTOM, OR IDLE CONCERN WITH OR WITHOUT MIL ILLUMINATION/DTC'S DUE TO THE PCM ENGINE HARNESS CHAFFING AGAINST THE PCM MOUNTING BRACKET.
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 2008 mercury mountaineer. The contact stated that while driving approximately 75 MPH, the vehicle would stall and the wrench warning light would illuminate. The vehicle was able to be restarted after a several attempts. The failure would occur on an intermittent basis. The vehicle was inspected by a dealer and they were unable to diagnose the failure. The vehicle was not…
Had engine trouble with your 2008 Mercury Mountaineer?
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 2008 Mercury Mountaineer?
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 143,200 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/2008/Mercury/Mountaineer.
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.