# Ford Explorer 2006–2010 Problems, Reliability & Costs

Canonical: https://carcasefile.com/vehicles/ford-explorer-2006-2010/

> Ford Explorer 2006–2010: the 5R55S transmission and timing chain issues to check, real repair costs, why the V8 is the smart buy, and the best years.

Case file · FORD-EXPLORER-2006-2010 · 4th gen (U251)

# Ford Explorer 2006–2010 Common problems, reliability & repair costs

The 4th-gen Explorer is the last of the body-on-frame, truck-based Explorers. It has genuinely tough bones and two expensive weak points. The 4.0L V6's timing chain cassettes and the 5R55S automatic behind it generate most of the horror stories, and 2006 in particular racked up a complaint spike CarComplaints flagged as the worst Explorer year. The 4.6L V8 with its 6-speed sidesteps both problems, and 2009–2010 cars of either engine are dramatically cleaner.

[Shop Ford Explorer parts on Amazon →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DFord%2BExplorer%2Bparts) Verified part numbers below Affiliate link to Amazon. We may earn a commission if you buy. Your price is the same, and a commission never changes a verdict.

Case data plate FORD-EXPLORER-2006-2010

Case score
4/10

Best years

2009, 2010

Avoid

2006 (CarComplaints' worst Explorer year: transmission and r +1 more

Status
Reviewed
Amended 2026-09-23

[How we score →](https://carcasefile.com/methodology/)

Exhibit A · Ford Explorer IFCAR · Public domain · [Wikimedia](https://commons.wikimedia.org/wiki/File:2006-2010_Ford_Explorer_--_01-07-2012.jpg)

Case verdict At a glance

Case score
4/10

Best years

2009, 2010

Years to avoid

2006 (CarComplaints' worst Explorer year: transmission and r +1 more

Worst system

engine

#1 problem

**4.0L SOHC timing chain cassette / tensioner failure** · $2,000–$5,000 at an independent shop · typically around 75k–150k mi

Companion pages for this car generation:

📄 Dossier Overview Active Page [📋 Inspection Checklist Field Guide ->](https://carcasefile.com/vehicles/ford-explorer-2006-2010/checklist/) [💰 Maintenance Costs 5-Year Ledger ->](https://carcasefile.com/vehicles/ford-explorer-2006-2010/cost-to-maintain/) [🩺 Audit a Quote Estimate Case File ->](https://carcasefile.com/estimate-doctor/?vehicle=Ford%20Explorer)

## Engines

- **4.0L SOHC (Cologne)** · 4.0L gasoline, 210 hp
- **4.6L 3V (Modular)** · 4.6L gasoline, 292 hp

## Transmissions

- **5R55S**· automatic, 5-speed
- **6R60**· automatic, 6-speed
- **6R80**· automatic, 6-speed

## Drivetrain

RWD / 4WD / AWD

## Body

SUV (4-door)

## Trims

XLS, XLT, Eddie Bauer, Limited

Parts desk

## Ford Explorer part-number cross-reference

Start from the OEM number, then pick the brand you trust. Verified equivalents for the Ford Explorer (2006–2010).

Part links go to Amazon, and to eBay where Amazon does not stock the part.
Affiliate links, so we may earn a commission if you buy. Your price is
unchanged, and a commission never changes a verdict.

### Oil filter

Both engines: 4.0L SOHC V6 and 4.6L 3V V8 (shared filter)
swipe →

OEM part
Motorcraft

Ford F1AZ-6731-BD; the common Ford spin-on, same filter for the V6 and V8
[Find Motorcraft oil filter on Amazon](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000AS3D3S)

Cross-ref Verified fit · 07.26

Wix

57502 = XP synthetic-media upgrade
[Look up Wix oil filter](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000C9Y14A)

Cross-ref Verified fit · 07.26

Fram

Tough Guard TG2 / Ultra XG2 share the base number
[Check Fram oil filter](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DFram%2BPH2)

Cross-ref Verified fit · 07.26

ACDelco
[See ACDelco oil filter](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000C9TVCC)

Cross-ref Verified fit · 07.26

Bosch

Premium; 72212 is the Distance Plus version
[Compare Bosch oil filter](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB002EBSLP4)

Cross-ref Verified fit · 07.26

Mobil 1
[Find Mobil 1 oil filter](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DMobil%2B1%2BM1-210)

Verified via: [oilfilter-crossreference.com - Motorcraft FL-820S equivalents (Wix 51372, Fram PH2, ACDelco PF1250)](https://www.oilfilter-crossreference.com/convert/MOTORCRAFT/FL-820S), [K&N - 2008 Explorer 4.0L V6 oil filter (FL820S application)](https://www.knfilters.com/oil-filters/ford/explorer/4.0l-v6-gas/2008), [eBay - Genuine Motorcraft oil-change kit, 2008 Explorer Sport Trac 4.6L V8, FL820S (V8 fitment)](https://www.ebay.com/itm/186388561815)

### Engine air filter

4.0L SOHC V6
swipe →

OEM part
Motorcraft

Ford 1L2Z-9601-AA. The V6 uses a DIFFERENT air filter than the V8 - do not cross them
[Look up Motorcraft engine air filter on Amazon](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DMotorcraft%2BFA-1695)

Cross-ref Verified fit · 07.26

Wix
[Check Wix engine air filter](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000C9TBQ8)

Cross-ref Verified fit · 07.26

Fram
[See Fram engine air filter](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB0009H520W)

Cross-ref Verified fit · 07.26

Purolator
[Compare Purolator engine air filter](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DPurolator%2BA25418)

Cross-ref Verified fit · 07.26

K&N

washable
[Find K&N engine air filter](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB00062ZVDI)

Cross-ref Verified fit · 07.26

Baldwin
[Look up Baldwin engine air filter](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000CAYRCU)

Verified via: [airfilter-crossreference.com - Motorcraft FA1695 equivalents (Wix 42484, Fram CA9332, K&N 33-2207)](https://www.airfilter-crossreference.com/convert/MOTORCRAFT/FA1695), [CarParts - Motorcraft FA1695 fits 2006 Explorer 4.0L V6](https://www.carparts.com/details/Ford/Explorer/Motorcraft/Air_Filter/2006/MIFA1695.html)

### Engine air filter

4.6L 3V V8
swipe →

OEM part
Motorcraft

Ford 6L2Z-9601-AA (FA-1780-A). The V8 filter is a different part from the V6's FA-1695
[Check Motorcraft engine air filter on Amazon](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DMotorcraft%2BFA-1780)

Cross-ref Verified fit · 07.26

Wix
[See Wix engine air filter](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000IYH5KQ)

Cross-ref Verified fit · 07.26

Fram
[Compare Fram engine air filter](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB0010E3ITU)

Cross-ref Verified fit · 07.26

Purolator
[Find Purolator engine air filter](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DPurolator%2BA35633)

Cross-ref Verified fit · 07.26

Mann
[Look up Mann engine air filter](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB001DRLPW6)

Verified via: [airfilter-crossreference.com - Motorcraft FA-1780 equivalents (Wix 49145, Fram CA10173, Purolator A35633)](https://www.airfilter-crossreference.com/convert/MOTORCRAFT/FA-1780), [Walmart - Motorcraft FA-1780 fits select 2006-2010 Explorer / 4.6L V8](https://www.walmart.com/ip/Motorcraft-Air-Filter-FA-1780-Fits-select-2006-2010-FORD-EXPLORER-2007-2010-FORD-EXPLORER-SPORT-TRAC/33678805)

### Cabin air filter

2006-2010 Explorer: NOT EQUIPPED from the factory. The 4th-gen HVAC box has no filter slot and no OEM cabin filter is cataloged for these years; air enters unfiltered. Adding one means cutting the case behind the glovebox (owner retrofit). Nothing to buy or replace on a stock truck.
swipe →

Verified via: [Ford Explorer Forums - Does the 2010 Explorer have a cabin air filter? (consensus: no factory filter)](https://www.explorerforum.com/forums/threads/does-the-2010-explorer-have-a-cabin-air-filter.364553/), [Ford Explorer Forums - fitting a cabin filter requires cutting the HVAC housing (no factory provision)](https://www.explorerforum.com/forums/threads/how-to-install-cabin-air-filter-pictures.328559/)

### Spark plugs

4.0L SOHC V6
swipe →

OEM part
Motorcraft

plug marking AGSF-24N (SP-412X is the same plug), nickel. Gap 0.052-0.056 in (Ford)
[Check Motorcraft spark plugs on Amazon](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DMotorcraft%2BSP-412)

Cross-ref Verified fit · 07.26

Autolite

iridium XP; platinum equivalent is AP5143
[See Autolite spark plugs](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DAutolite%2BXP5143)

Cross-ref Verified fit · 07.26

NGK

platinum (G-Power); copper V-Power #2683 ships gapped 0.060 - re-gap to ~0.054
[Compare NGK spark plugs](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DNGK%2B7159)

Cross-ref Verified fit · 07.26

Denso

platinum
[Find Denso spark plugs](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DDenso%2B4512)

Cross-ref Verified fit · 07.26

Champion

iridium; copper #403 also fits
[Look up Champion spark plugs](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DChampion%2B9200)

Cross-ref Verified fit · 07.26

Bosch

platinum
[Check Bosch spark plugs](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB007BLMXCE)

Verified via: [Ford 2009 Explorer owner guide, engine specifications, plug gap (p394)](https://www.fordservicecontent.com/Ford_Content/catalog/owner_guides/09expog3e.pdf), [RockAuto - 2008 Explorer 4.0L V6 spark plug fitment (Motorcraft SP412X, Autolite XP5143, NGK, Denso, Champion, Bosch)](https://www.rockauto.com/en/catalog/ford,2008,explorer,4.0l+v6,1441674,ignition,spark+plug,7212), [sparkplug-crossreference.com - Motorcraft SP-412 / AGSF-24N equivalents](https://www.sparkplug-crossreference.com/convert/MTRCRFT_PN/SP-412)

### Spark plugs

4.6L 3V V8 - engines built BEFORE 11/30/2007 (the two-piece-plug design)
swipe →

OEM part
Motorcraft

original two-piece plug (marking PZH1F; supersedes SP-462). THIS is the plug that carbon-seizes and snaps off in the head on removal - Ford TSB 08-7-6. Gap 0.045 in
[See Motorcraft spark plugs on Amazon](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB004A2BGAW)

Cross-ref Verified fit · 07.26

Motorcraft

updated one-piece finewire-platinum replacement - install these instead of the two-piece SP-514 so it never happens again
[Compare Motorcraft spark plugs](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB074LJG2HX)

Cross-ref Verified fit · 07.26

Champion

double platinum; RockAuto lists it for cam-cover build date BEFORE 11/30/2007
[Find Champion spark plugs](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DChampion%2B7989)

Verified via: [RockAuto - 2008 Explorer 4.6L V8 spark plug fitment (Motorcraft SP514/SP547; Champion 7989 tagged 'before 11/30/2007')](https://www.rockauto.com/en/catalog/ford,2008,explorer,4.6l+v8,1441671,ignition,spark+plug,7212), [Walmart - OEM Motorcraft SP514/SP547 set, Ford updated one-piece design PZH1F](https://www.walmart.com/ip/New-OEM-Motorcraft-SP514-SP547-Set-of-8-Spark-Plugs-Finewire-Platinum-Ford-Updated-Design-PZH1F/734460360)

### Spark plugs

4.6L 3V V8 - engines built ON/AFTER 11/30/2007 (revised head, conventional one-piece plug)
swipe →

OEM part
Motorcraft

plug marking HJFS-24FP (SP-509X is the same plug); platinum; gap ~0.041 in. Do NOT use the pre-11/30/2007 SP-514/SP-547 - different design
[Look up Motorcraft spark plugs on Amazon](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DMotorcraft%2BSP-509)

Cross-ref Verified fit · 07.26

Champion

double platinum; RockAuto lists it for cam-cover build date AFTER 11/30/2007
[Check Champion spark plugs](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DChampion%2B7406)

Verified via: [RockAuto - 2008 Explorer 4.6L V8 spark plug fitment (Motorcraft SP509X; Champion 7406 tagged 'after 11/30/2007')](https://www.rockauto.com/en/catalog/ford,2008,explorer,4.6l+v8,1441671,ignition,spark+plug,7212), [AutoZone - Motorcraft SP-509-X double platinum (2008-2010 Explorer 4.6L V8)](https://www.autozone.com/p/motorcraft-spark-plug-sp-509-x/10306)

### Front brake pads

Front axle, both engines (2006-2010 Explorer / 2007-2010 Sport Trac)
swipe →

OEM part
Motorcraft

Ford 6L2Z-2001-A (also sold as BRF-1158); FMSI D1158
[See Motorcraft front brake pads on Amazon](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DMotorcraft%2BBR-1158-C)

Cross-ref Verified fit · 07.26

Wagner

QuickStop ceramic; ThermoQuiet is QC1158
[Compare Wagner front brake pads](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB001DRBYAY)

Cross-ref Verified fit · 07.26

Raybestos

R-Line ceramic
[Find Raybestos front brake pads](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB01MSTFSNA)

Cross-ref Verified fit · 07.26

Bosch

Blue ceramic
[Look up Bosch front brake pads](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB082WD655C)

Cross-ref Verified fit · 07.26

Power Stop

Z17 low-dust ceramic
[Check Power Stop front brake pads](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DPower%2BStop%2B17-1158)

Cross-ref Verified fit · 07.26

Centric

C-TEK ceramic
[See Centric front brake pads](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DCentric%2B103.11580)

Verified via: [RockAuto - 2008 Explorer front disc brake pad fitment (Motorcraft BR1158C, Wagner ZD1158, Raybestos MGD1158CH, Bosch, Power Stop)](https://www.rockauto.com/en/catalog/ford,2008,explorer,4.0l+v6,1441674,brake+&+wheel+hub,disc+brake+pad,1684), [Ford OEM parts - Motorcraft BR-1158-C disc brake pad set, 2006-2010 Explorer](https://ford.oempartsonline.com/oem-parts/ford-motorcraft-disc-brake-pad-set-br1158c)

### Wiper blades

Front pair 20 in / 20 in; rear 13 in (consistent 2006-2010)
swipe →

OEM part
Ford (factory sizes)
[Compare Ford wiper blades on Amazon](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DFord%2B%2528factory%2Bsizes%2529%2B20%2Bin%2Bdriver%252C%2B20%2Bin%2Bpassenger%252C%2B13%2Bin%2Brear)

Cross-ref Verified fit · 07.26

Bosch ICON

beam blades in factory front sizes
[Find Bosch ICON wiper blades](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DBosch%2BICON%2B20A%2Bdriver%2B%252B%2B20A%2Bpassenger)

Cross-ref Verified fit · 07.26

Trico / Rain-X

select by length
[Look up Trico / Rain-X wiper blades](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DTrico%2B%252F%2BRain-X%2B20%2Bin%2Bfront%2Bpair%252C%2B13%2Bin%2Brear)

Verified via: [MyWiperSize - Ford Explorer wiper sizes (20/20 front)](https://www.mywipersize.com/make/ford/explorer.php), [WiperSizeChart - 2006 Explorer (20 in / 20 in + 13 in rear)](https://www.wipersizechart.com/make/ford/explorer/2006)

### Serpentine belt

4.0L SOHC V6 (with A/C; drives ALT/PS/AC/WP, 6-rib)
swipe →

OEM part
Motorcraft

Ford 9L2Z-8620-A; 6-rib, ~86 in - shorter than the V8 belt
[Check Motorcraft serpentine belt on Amazon](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DMotorcraft%2BJK6-865-B)

Cross-ref Verified fit · 07.26

Gates

Micro-V, 6-rib
[See Gates serpentine belt](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000C2SII2)

Cross-ref Verified fit · 07.26

Dayco
[Compare Dayco serpentine belt](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DDayco%2B5060860)

Cross-ref Verified fit · 07.26

Continental

also Bando 6PK2185
[Find Continental serpentine belt](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DContinental%2B4060860)

Cross-ref Verified fit · 07.26

ACDelco
[Look up ACDelco serpentine belt](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000C9RNOK)

Verified via: [RockAuto - 2008 Explorer 4.0L V6 drive belt (Motorcraft JK6865B, Gates K060860, Dayco 5060860, ACDelco 6K860)](https://www.rockauto.com/en/catalog/ford,2008,explorer,4.0l+v6,1441674,belt+drive,belt,8900), [Lakeland Ford - 2008 Explorer 4.0L V6 serpentine belt 9L2Z-8620-A](https://parts.lakelandford.com/p/Ford_2008_Explorer-40L-V6-AT-4WD/Serpentine-Belt/52399736/9L2Z8620A.html)

### Serpentine belt

4.6L 3V V8 (with A/C; drives ALT/PS/AC/WP, 6-rib)
swipe →

OEM part
Motorcraft

Ford 7L2Z-8620-A; 6-rib, ~102.5 in - longer than the V6 belt, not interchangeable
[Check Motorcraft serpentine belt on Amazon, 4.6L](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DMotorcraft%2BJK6-1032-AC)

Cross-ref Verified fit · 07.26

Gates

Micro-V, 6-rib; FleetRunner HD is K061025HD
[See Gates serpentine belt, 4.6L](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DGates%2BK061025)

Cross-ref Verified fit · 07.26

Dayco
[Compare Dayco serpentine belt, 4.6L](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000C0YMY8)

Cross-ref Verified fit · 07.26

Continental

also Bando 6PK2605
[Find Continental serpentine belt, 4.6L](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DContinental%2B4061025)

Cross-ref Verified fit · 07.26

ACDelco
[Look up ACDelco serpentine belt, 4.6L](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000C9MEGC)

Verified via: [RockAuto - 2008 Explorer 4.6L V8 drive belt (Motorcraft JK61032AC, Gates K061025, Dayco 5061025, ACDelco 6K1025)](https://www.rockauto.com/en/catalog/ford,2008,explorer,4.6l+v8,1441671,belt+drive,belt,8900), [Ford OEM parts - Motorcraft serpentine belt JK6-1032-AC (Explorer 4.6L)](https://ford.oempartsonline.com/oem-parts/ford-motorcraft-trade-serpentine-belt-jk61032ac)

### Battery (BCI group)

Both engines, 2006-2010
swipe →

OEM part
Motorcraft

BCI Group 65, 650 CCA, Ford's listed part for both engines 2006-2010 (2006 p314, 2007 p353, 2008 p380, 2009 p389, 2010 p386). BXT-65-750 and -850 are higher-CCA upgrades.
[Check Motorcraft battery on Amazon](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DMotorcraft%2BBXT-65-650)

Cross-ref Verified fit · 07.26

BCI Group 65 (any brand)

e.g. Duralast 65-DLG, EverStart Maxx 65N; match factory CCA
[See BCI Group 65 battery](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DBCI%2BGroup%2B65%2B%2528any%2Bbrand%2529%2BGroup%2B65%252C%2B650-850%2BCCA)

Verified via: [Ford 2006 Explorer owner guide, Motorcraft parts table (p314)](https://www.fordservicecontent.com/Ford_Content/catalog/owner_guides/06expog2e.pdf), [Ford 2010 Explorer owner guide, Motorcraft parts table (p386)](https://www.fordservicecontent.com/Ford_Content/catalog/owner_guides/10expog2e.pdf), [Ford.com - Motorcraft BXT-65-750 (Group 65, 750 CCA), upgrade option](https://www.ford.com/product/vehicle-battery-p4000109952), [Ford Explorer Forums - Group 65 battery (BXT-65-650 vs -850)](https://www.explorerforum.com/forums/threads/battery-bxt-65-650-vs-65-850.389663/)

Amazon and eBay affiliate links. Prices unchanged for you. Confirm fitment against your VIN; mid-generation changes exist.

Verdict

## Should I buy a 2006–2010 Ford Explorer?

Buy the right one, skip the rest. The safest 4th-gen Explorer is a 2009–2010. Complaint volume falls off a cliff after 2008. The 4.6L V8 is the smarter engine because it dodges both the 5R55S transmission and the V6 timing chain cassettes. A 2006 4.0L V6 is the riskiest combination in the lineup: the worst-year transmission complaints, radiator leaks, and chain cassettes all converge on it. If you're set on a V6 car, budget for the transmission like it's already failing and walk away from anything that rattles on cold start. As cheap 4x4 family haulers and tow rigs go, a clean late V8 car is a legitimately good buy.

Best years

2009, 2010

Years to avoid

2006 (CarComplaints' worst Explorer year: transmission and radiator complaint spike), 2007 4.0L V6 (same 5R55S and cassette risks, only modestly improved)

Inspection Companion

### Pre-Purchase Checklist for Ford Explorer

[Open Field Checklist Page ->](https://carcasefile.com/vehicles/ford-explorer-2006-2010/checklist/)

- ☐ Cold-start the engine yourself (V6 cars). A rattle or 'bucket of bolts' clatter for the first seconds is the classic timing chain cassette/tensioner warning. Walk away or price in a major engine job.
- ☐ On V6 cars, drive it through the 1-2 and 2-3 shifts from a stop, both gentle and firm. Harsh jolts, a flare (revs jump between gears), or a delayed/banging reverse engagement point to the 5R55S servo bore/solenoid problem.
- ☐ Cold engine only: open the hood and check the radiator tank seams for dried coolant crust or wetness. Plastic end-tank radiator leaks are a documented pattern on this generation.
- ☐ Listen for a droning hum at 40–60 mph and gently weave within the lane; a hum that changes with steering load means a wheel bearing/hub on its way out.
- ☐ On 4.6L V8 cars built before late 2007, ask whether the spark plugs have already been changed (ideally to one-piece plugs). Original two-piece plugs routinely break off in the heads on removal.
- ☐ On 4WD trucks, cycle 4X4 HIGH and 4X4 LOW on a loose surface and confirm it engages and disengages without binding or warning lights. On 2008-2010 V8 AWD trucks, set AWD to LOCKED in the message center and confirm the 4X4 light comes on.
- ☐ Run the VIN for open recalls, including the wiper motor gear recall (NHTSA 05V520000), and pull a history report.

Verified-fit parts for the Ford Explorer (2006–2010).

Parts desk

Parts cross-reference

OEM number first, verified equivalents below it. Links go to Amazon.

Oil filter

Both engines: 4.0L SOHC V6 and 4.6L 3V V8 (shared filter)

- [OEM Motorcraft FL-820S →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000AS3D3S)
- [Wix 51372 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000C9Y14A)
- [Fram PH2 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DFram%2BPH2)
- [ACDelco PF1250 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000C9TVCC)
- [Bosch 3410 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB002EBSLP4)
- [Mobil 1 M1-210 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DMobil%2B1%2BM1-210)

Engine air filter

4.0L SOHC V6

- [OEM Motorcraft FA-1695 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DMotorcraft%2BFA-1695)
- [Wix 42484 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000C9TBQ8)
- [Fram CA9332 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB0009H520W)
- [Purolator A25418 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DPurolator%2BA25418)
- [K&N 33-2207 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB00062ZVDI)
- [Baldwin PA4147 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000CAYRCU)

Engine air filter

4.6L 3V V8

- [OEM Motorcraft FA-1780 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DMotorcraft%2BFA-1780)
- [Wix 49145 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000IYH5KQ)
- [Fram CA10173 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB0010E3ITU)
- [Purolator A35633 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DPurolator%2BA35633)
- [Mann MA1152 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB001DRLPW6)

Cabin air filter

2006-2010 Explorer: NOT EQUIPPED from the factory. The 4th-gen HVAC box has no filter slot and no OEM cabin filter is cataloged for these years; air enters unfiltered. Adding one means cutting the case behind the glovebox (owner retrofit). Nothing to buy or replace on a stock truck.

Spark plugs

4.0L SOHC V6

- [OEM Motorcraft SP-412 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DMotorcraft%2BSP-412)
- [Autolite XP5143 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DAutolite%2BXP5143)
- [NGK 7159 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DNGK%2B7159)
- [Denso 4512 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DDenso%2B4512)
- [Champion 9200 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DChampion%2B9200)
- [Bosch 6715 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB007BLMXCE)

Spark plugs

4.6L 3V V8 - engines built BEFORE 11/30/2007 (the two-piece-plug design)

- [OEM Motorcraft SP-514 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB004A2BGAW)
- [Motorcraft SP-547 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB074LJG2HX)
- [Champion 7989 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DChampion%2B7989)

Spark plugs

4.6L 3V V8 - engines built ON/AFTER 11/30/2007 (revised head, conventional one-piece plug)

- [OEM Motorcraft SP-509 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DMotorcraft%2BSP-509)
- [Champion 7406 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DChampion%2B7406)

Front brake pads

Front axle, both engines (2006-2010 Explorer / 2007-2010 Sport Trac)

- [OEM Motorcraft BR-1158-C →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DMotorcraft%2BBR-1158-C)
- [Wagner ZD1158 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB001DRBYAY)
- [Raybestos MGD1158CH →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB01MSTFSNA)
- [Bosch BE1158H →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB082WD655C)
- [Power Stop 17-1158 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DPower%2BStop%2B17-1158)
- [Centric 103.11580 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DCentric%2B103.11580)

Wiper blades

Front pair 20 in / 20 in; rear 13 in (consistent 2006-2010)

- [OEM Ford (factory sizes) 20 in driver, 20 in passenger, 13 in rear →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DFord%2B%2528factory%2Bsizes%2529%2B20%2Bin%2Bdriver%252C%2B20%2Bin%2Bpassenger%252C%2B13%2Bin%2Brear)
- [Bosch ICON 20A driver + 20A passenger →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DBosch%2BICON%2B20A%2Bdriver%2B%252B%2B20A%2Bpassenger)
- [Trico / Rain-X 20 in front pair, 13 in rear →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DTrico%2B%252F%2BRain-X%2B20%2Bin%2Bfront%2Bpair%252C%2B13%2Bin%2Brear)

Serpentine belt

4.0L SOHC V6 (with A/C; drives ALT/PS/AC/WP, 6-rib)

- [OEM Motorcraft JK6-865-B →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DMotorcraft%2BJK6-865-B)
- [Gates K060860 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000C2SII2)
- [Dayco 5060860 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DDayco%2B5060860)
- [Continental 4060860 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DContinental%2B4060860)
- [ACDelco 6K860 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000C9RNOK)

Serpentine belt

4.6L 3V V8 (with A/C; drives ALT/PS/AC/WP, 6-rib)

- [OEM Motorcraft JK6-1032-AC →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DMotorcraft%2BJK6-1032-AC)
- [Gates K061025 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DGates%2BK061025)
- [Dayco 5061025 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000C0YMY8)
- [Continental 4061025 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DContinental%2B4061025)
- [ACDelco 6K1025 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fdp%2FB000C9MEGC)

Battery (BCI group)

Both engines, 2006-2010

- [OEM Motorcraft BXT-65-650 →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DMotorcraft%2BBXT-65-650)
- [BCI Group 65 (any brand) Group 65, 650-850 CCA →](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3DBCI%2BGroup%2B65%2B%2528any%2Bbrand%2529%2BGroup%2B65%252C%2B650-850%2BCCA)

Confirm fitment against your VIN. Mid-generation changes exist. Affiliate links. We may earn a commission at no cost to you.

Known faults

## Common Ford Explorer problems & repair costs

### 5R55S transmission hard shifting / servo bore and solenoid failure (4.0L V6)

$1,500–$3,800

transmission severe 2006–2010 (4.0L V6 cars; 2006–2007 worst) ~50k–120k mi

**Symptoms:** Hard, lunging 1-2 and 2-3 shifts; RPM flare between 2nd and 3rd; delayed or banging reverse engagement; codes P0775, P0732/P0733/P0735. CarComplaints logs 308 transmission complaints on the 2006 alone, with problems starting as low as 40k–49k miles.

**Fix:** The root cause is usually worn servo pin bores in the case (fixed with oversized-sleeve servo bore kits) and/or a failed solenoid block. Caught early, a servo bore repair plus solenoid pack is the cheaper path. Ignored, it becomes a full rebuild or replacement in the $2,500–$3,800 range. The V8's 6-speed (6R60 in 2006-2008, 6R80 in 2009-2010) does not share this problem.

Sources: [CarComplaints: 2006 Explorer transmission](https://www.carcomplaints.com/Ford/Explorer/2006/transmission/), [Transmission Repair Cost Guide: Ford Explorer 5R55](https://www.transmissionrepaircostguide.com/ford-explorer-transmission-problems/), [Ford Explorer Forums: 5R55S servo bore fix thread](https://www.explorerforum.com/forums/threads/5r55s-servo-bore-fix-fail-after-classic-symptoms.478406/)

### 4.0L SOHC timing chain cassette / tensioner failure

$2,000–$5,000

engine severe 2006–2010 (4.0L V6) ~75k–150k mi

**Symptoms:** Rattle or clatter on cold start that quiets after a few seconds. The plastic chain guides (cassettes) wear and the spring-loaded tensioners weaken, letting the chains whip. Left alone, the noise becomes constant, cassette debris ends up in the oil pan, and a jumped chain takes the engine with it.

**Fix:** External tensioner replacement (~every 75k miles per owner-forum consensus) is cheap insurance. Once cassettes are breaking up, the rear cassette sits at the back of the engine and requires pulling the engine, which is why quotes land in used-engine-swap territory. Address the noise early or buy the V8.

Sources: [Ford Explorer Forums: timing chain cassettes in the 4.0L SOHC](https://www.explorerforum.com/forums/threads/timing-chain-cassettes-in-2008-4-0-liter-sohc-reliability-verdict.473209/), [Ford Explorer Forums: 4.0L tensioner replacement schedule](https://www.explorerforum.com/forums/threads/4-0l-engine-timing-chain-tensioners-replacement-schedule.444417/)

### Radiator leaks

$450–$900

cooling moderate 2006–2010 (2006–2007 most reported) ~60k–70k mi

**Symptoms:** Coolant loss, crusty residue or seepage at the plastic end-tank seams, sweet smell, low-coolant or temperature warnings. CarComplaints logs 246 cooling-system complaints on the 2006, with radiator leaks averaging about $700 to fix at roughly 64,000 miles, and some owners report replacement radiators failing the same way.

**Fix:** Radiator replacement with fresh coolant. It's a bolt-in job on this truck; pick a quality unit rather than the cheapest aftermarket radiator, since repeat failures are part of the complaint record.

Sources: [CarComplaints: 2006 Explorer cooling system](https://www.carcomplaints.com/Ford/Explorer/2006/cooling_system/)

### 4.6L V8 two-piece spark plugs break on removal

$150–$700

engine moderate 2006 to engines built before Nov 30, 2007 ~Whenever plugs are first changed (often 100k mi)

**Symptoms:** No driving symptom. This is a maintenance trap. The original Motorcraft two-piece plugs carbon-seize in the heads, and the lower shell snaps off below the threads during removal, leaving the tip stuck in the head.

**Fix:** Ford TSB 08-7-6 gives the official procedure: cold engine, back each plug out 1/8–1/4 turn, soak with carb cleaner for at least 15 minutes, then work them out slowly. Broken tips need a special extractor (or a shop that owns one). Replace with updated one-piece plugs so it never happens again. A car with documented plug replacement has already cleared this landmine.

Sources: [Ford TSB 08-7-6: spark plug removal procedure (PDF)](https://www.aa1car.com/library/ford_tsb_08-7-6.pdf), [Engine Builder: removing problem plugs on Ford modular engines](https://www.enginebuildermag.com/2013/08/damage-control-removing-problem-plugs-on-ford-modular-engines/)

### Wheel bearing / hub assembly failures

$350–$700

suspension moderate 2006–2010 ~80k–130k mi (repeat failures reported much sooner with cheap parts)

**Symptoms:** Humming or droning that rises with road speed and changes when you swerve gently side to side; sometimes ABS sensor codes from the affected corner.

**Fix:** Replace the hub/bearing assembly. The front units are bolt-on. Owner forums are consistent on one point: budget bearings fail again fast; use a quality brand (Timken/SKF/Motorcraft) and torque the axle nut to spec.

Sources: [Ford Explorer Forums: chronic wheel hub/bearing issues (2008 4WD)](https://www.explorerforum.com/forums/threads/chronic-wheel-hub-bearing-issues-2008-4wd-4dr-v6-xlt.506077/), [CarComplaints: 2007 Explorer wheel bearing failure](https://www.carcomplaints.com/Ford/Explorer/2007/wheels_hubs/wheel_bearing_failure.shtml)

Day to day, a 4th-gen Explorer is cheap to run: parts are everywhere, the truck-frame layout is easy to work on, and routine wear items (brakes, bearings, radiators) are all DIY-friendly money. The budget-killers are concentrated in the 4.0L V6 driveline: a 5R55S rebuild and a timing-cassette job can each run $2,500–$5,000, which often exceeds the value of an early car. V8 cars trade those risks for one $150–$700 spark-plug event and slightly worse fuel economy. Whichever engine, plan on 15–17 mpg combined and tires/brakes sized for a 4,500 lb truck.

Cost calculator

### What will this Ford Explorer cost you by a given mileage?

Drag to a mileage. We total the documented problems whose typical onset falls at or before it. The same cost ranges listed above, nothing new invented.

100k mi

$0 estimated repair range

Ownership Costs
5-Year Maintenance Schedule & Cost to Own

Every scheduled service by mileage, fluid capacities, independent shop ranges, and parts cross-references.

[Open 5-Year Ledger ->](https://carcasefile.com/vehicles/ford-explorer-2006-2010/cost-to-maintain/)

🩺
Have a repair quote for this Ford Explorer?

Audit against OEM book times, uncover duplicate pad and rotor labor, and verify parts markups.

[Audit Repair Estimate ->](https://carcasefile.com/estimate-doctor/?vehicle=Ford%20Explorer)

DIY repairs

## How to fix common Ford Explorer problems (DIY)

### Replace the radiator

moderate 2–3 hrs saves ~$250–$450

**Tools:** Socket set + screwdrivers, Drain pan, Hose-clamp pliers, Fresh coolant (Motorcraft Gold spec)

- Cold engine only: drain the coolant from the radiator petcock into a pan.
- Disconnect the upper and lower radiator hoses and the transmission cooler lines (they drip, so have a catch pan ready).
- Unbolt the fan shroud and upper radiator supports, then lift the radiator out.
- Drop in the new radiator, reconnect cooler lines, hoses, and shroud.
- Refill with the correct coolant, bleed the air out at idle with the heater on hot, and check for leaks and proper transmission fluid level.

Parts

- [Radiator (2006–2010 Ford Explorer)](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3D2006-2010%2Bford%2Bexplorer%2Bradiator) · Amazon $120–$250

### Replace a front wheel hub/bearing assembly

moderate 1.5–2.5 hrs per side saves ~$150–$300 per side

**Tools:** Floor jack + jack stands, Socket set + breaker bar, Large axle-nut socket, Torque wrench, Penetrating oil

- Jack and support the truck, remove the wheel, and unbolt the brake caliper and rotor.
- Unplug the ABS sensor connector and remove the axle nut (4WD).
- Unbolt the three hub retaining bolts behind the knuckle. Soak them with penetrant first.
- Pull the old hub assembly, clean the knuckle bore, and seat the new unit.
- Torque the hub bolts and axle nut to spec. Over- or under-torquing the axle nut is the top cause of early repeat failure.
- Reassemble brakes, plug in the ABS sensor, and test drive listening for the hum.

Parts

- [Front hub/bearing assembly (2006–2010 Explorer)](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3D2006-2010%2Bford%2Bexplorer%2Bfront%2Bwheel%2Bhub%2Bbearing%2Bassembly) · Amazon $60–$150

### Change 4.6L V8 spark plugs the TSB way (without breaking them)

hard 3–5 hrs saves ~$300–$600 (far more if a shop has to extract broken plugs)

**Tools:** Spark plug socket + extensions, Torque wrench, Carburetor cleaner (for the soak), Broken-plug extractor kit (insurance)

- Work on a stone-cold engine only. This is the single most important rule in Ford TSB 08-7-6.
- Remove the coils, blow debris out of the plug wells, and back each plug out just 1/8 to 1/4 turn.
- Fill each plug well with about 1/2–3/4 teaspoon of carb cleaner and let it soak at least 15 minutes.
- Work each plug out slowly, backing up and re-soaking if you feel it start to bind.
- Install updated one-piece plugs with a dab of nickel anti-seize, torqued to spec, and reinstall the coils.

Parts

- [One-piece spark plugs (4.6L 3V, set of 8)](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3Dford%2B4.6%2B3v%2Bone%2Bpiece%2Bspark%2Bplugs) · Amazon $60–$110
- [Broken spark plug extractor (Ford 3V)](https://carcasefile.com/go?u=https%3A%2F%2Fwww.amazon.com%2Fs%3Fk%3Dford%2B3v%2Bbroken%2Bspark%2Bplug%2Bextractor) · Amazon $40–$90

Some parts links are affiliate links. We may earn a commission at no cost to you. We only list parts that fit this generation.

## The short version

The 2006–2010 Explorer is the last truck-frame Explorer, and its reputation splits cleanly down the middle of the engine bay. The **4.0L SOHC V6** drags two well-documented, expensive problems behind it: timing chain cassettes and tensioners that announce themselves with a cold-start rattle and can end in an engine-out repair, and the **5R55S 5-speed automatic**, whose worn servo bores and solenoids made “transmission lunges, hard jolt when shifting” the top complaint on the 2006, the year CarComplaints tagged as the worst Explorer ever, with 779 total complaints.

The **4.6L V8** is a different truck. It got a robust 6-speed automatic and dodges the cassette problem entirely. Its one notable flaw, factory two-piece spark plugs that snap off in the heads on removal (Ford TSB 08-7-6), is a one-time maintenance event, not a recurring failure.

## What that means when you’re shopping

Year matters as much as engine. Complaint volume collapses after 2008: 779 complaints on the 2006, 15 on the 2009. A **2009–2010 4.6L V8** is the pick of the generation; a **2006–2007 4.0L V6** is the combination carrying nearly all the risk.

On any V6 car, do two things before money changes hands: cold-start it yourself and listen for the rattle, and drive it hard enough through the 1-2 and 2-3 shifts to feel a flare or jolt. Either symptom on a cheap car isn’t a bargaining chip. It’s the whole repair bill waiting for you. On a pre-late-2007 V8, ask whether the plugs were ever changed; documented one-piece replacements mean the landmine’s already been cleared.

## The stuff that’s just normal aging

Radiators weep from their plastic end tanks around 60k–70k miles, and wheel bearings hum their way out on these 4,500-pound trucks. Both are a few hundred dollars, bolt-on, and very DIY-able. Budget for them, don’t fear them.

## Bottom line

Score the generation low because of what the wrong configuration costs, not because every Explorer is a lemon. A clean late-year V8 with records is honest, capable, cheap 4x4 transportation.

**How this file is built:** failure modes and cost ranges are compiled from NHTSA recall records, CarComplaints.com complaint data, Ford TSB 08-7-6, and owner reporting on Ford Explorer Forums, then sanity-checked against shop-floor experience. Cost figures are independent-shop estimates and vary by region. Spot something off? [Tell us](https://carcasefile.com/disclaimer/).

Myths, checked

## Viral car myths, checked against this car

Misleading

### [Is the "$2 liquid that stops any leak" really banned in 11 states?](https://carcasefile.com/claims/2-dollar-stop-leak-banned-11-states/)

Automotive stop-leak products are not banned in any US state. The products are real (Bar's Leaks, BlueDevil), they work in specific narrow situations, and they can permanently damage your cooling or oiling system if applied to the wrong leak.

Misleading

### [Is the "$1 Japanese oil trick" that stops engine wear forever real?](https://carcasefile.com/claims/1-dollar-japanese-oil-trick-mos2-engine-wear/)

The 'Japanese oil trick' is almost certainly MoS2 (molybdenum disulfide), a real industrial friction modifier. It is German, not Japanese (Liqui Moly popularized it), sold openly at every parts store for $15-20, has real but modest measured friction benefits, and was never buried by anyone.

Appendix

## Frequently asked questions

### Which 2006–2010 Ford Explorer years should I avoid?

2006 is the one to treat with the most suspicion. CarComplaints flags it as the worst Explorer year on record, driven by 308 transmission complaints and 246 cooling-system complaints, many at low mileage. 2007 V6 cars carry most of the same risks. Complaint volume drops sharply from 2008 on, and 2009–2010 are the cleanest years of the generation by a wide margin.

### Is the 4.0L V6 or 4.6L V8 the better engine?

The V8, and it isn't close. The 4.6L pairs with a much stronger 6-speed automatic (6R60 through 2008, 6R80 for 2009-2010), sidestepping both the 5R55S transmission problems and the V6's timing chain cassette failures. It has one real trap: factory two-piece spark plugs that break on removal in pre-late-2007 builds. That is a known, one-time, few-hundred-dollar event, not a driveline lottery.

### My Explorer rattles for a few seconds on cold start. How bad is that?

On a 4.0L V6, take it seriously. That startup clatter is the classic sign of worn timing chain cassettes or weak tensioners, and the noise 'going away' after a few seconds doesn't mean the wear stops. Caught early, tensioners are a manageable job; ignored, cassette debris ends up in the oil pan and the rear cassette requires pulling the engine. Quotes routinely reach used-engine-swap money.

### Why does my V6 Explorer slam into gear or flare between 2nd and 3rd?

That's the signature 5R55S failure: the servo pin bores wear oval in the aluminum case, and the solenoid block fails, causing hard 1-2/2-3 shifts, RPM flares, and delayed reverse. Fixed early with servo bore sleeves and a solenoid pack it's a moderate bill; driven on, it becomes a $2,500–$3,800 rebuild.

### How many miles will a 4th-gen Explorer last?

The frame, axles, and 4.6L V8 are genuinely long-haul hardware. 200,000+ miles is realistic with maintenance. V6 cars can get there too, but usually only if someone stayed ahead of the timing chain tensioners and the transmission got serviced (or repaired) along the way. Condition and service history matter more than the odometer here.

Cross-reference

## Every Ford Explorer generation

The full case file run, beyond the generation before and after this one.

- [Ford Explorer 2011–2019 5/10](https://carcasefile.com/vehicles/ford-explorer-2011-2019/)
- [Ford Explorer 2020–present 5/10](https://carcasefile.com/vehicles/ford-explorer-2020-2024/)

## Cross-shopped rivals

Files on what buyers weigh against the Ford Explorer of this era.

- [GMC Acadia 2007–2016 4/10](https://carcasefile.com/vehicles/gmc-acadia-2007-2016/)
- [Toyota Highlander 2008–2013 8/10](https://carcasefile.com/vehicles/toyota-highlander-2008-2013/)
- [Honda Pilot 2009–2015 6/10](https://carcasefile.com/vehicles/honda-pilot-2009-2015/)
- [Kia Sorento 2011–2015 4/10](https://carcasefile.com/vehicles/kia-sorento-2011-2015/)

## More Ford case files

- [Ford Fusion 2006–2012 4/10](https://carcasefile.com/vehicles/ford-fusion-2006-2012/)
- [Ford Ranger 1998–2011 6/10](https://carcasefile.com/vehicles/ford-ranger-1998-2011/)
- [Ford Focus 2008–2011 7/10](https://carcasefile.com/vehicles/ford-focus-2008-2011/)
- [Ford F-150 2009–2014 6/10](https://carcasefile.com/vehicles/ford-f-150-2009-2014/)

Spot an error in this case file?

Wrong cost, a fault we missed, or a part number that doesn't fit. Tell us and we'll fix it. See our [verification methodology](https://carcasefile.com/methodology/) and [corrections policy](https://carcasefile.com/disclaimer/).

Reviewed CarCaseFile editorial · filed 2026-07-03 · updated 2026-09-23

Cost figures are independent-shop estimates and vary by region and condition. Always confirm a diagnosis before authorizing repairs.