How to check and replace the coolant temperature sensor on the Mercury Mountaineer?

The coolant temperature indicator system consists of a warning light or a temperature gauge on the dash and a coolant temperature-sending unit mounted on the engine. On the models covered, the Cylinder Head Temperature (CHT) sensor (V8 models)or Engine Coolant Temperature (ECT)sensor(V6 models), which is an information sensor for the Powertrain Control Module (PCM), also functions as the coolant temperature sending unit. If an overheating indication occurs check the coolant level in the system and make sure all connectors in the wiring harness between the sending unit and the indicator light or gauge are tight. When the ignition switch is turned to start and the starter motor is turning, the indicator light (if equipped) should come this doesn't mean the engine is overheated; it just means that the bulb is good. If the light doesn't come on when the ignition key is turned to START the bulb might be burned out, the ignition switch might be faulty or the circuit might be open. As soon as the engine starts, the indicator light should go out and remain off, unless the engine overheats. if the light doesn't go out, the wire between the sending unit and the light could be grounded, the sending unit might be defective, or the ignition switch might be faulty. Check the coolant to make sure it's correctly mixed; plain water. with no antifreeze, or coolant that's mainly water, might have too low a boiling point to activate the sending unit.

Genuine Mercury Mountaineer Coolant Temperature Sensor

Coolant Water Temperature Sensor

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7 Coolant Temperature Sensors found

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Mercury Mountaineer Temperature Sender Assembly
Part Number: F7DZ-10884-AA
$19.25 MSRP: $25.82
You Save: $6.57 (26%)
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Product Specifications
- Other Name: Sender Assembly - Temperature
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 1997-2001 Mercury Mountaineer | 6 Cyl 4.0L, 8 Cyl 5.0L | 4AT 4R70W, 5AT 5R55E
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Mercury Mountaineer Sender Assembly
Part Number: 1L2Z-12A648-AA
$35.26 MSRP: $48.18
You Save: $12.92 (27%)
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Product Specifications
- Other Name: Sender Assy
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2002 Mercury Mountaineer | 6 Cyl 4.0L SOHC EFI | 5-Speed Automatic Transmission 5R55S, 5-Speed Automatic Transmission 5R55W, 5-Speed Manual Transmission (M5R4), 6-Speed Automatic Transmission (6R80), 6-Speed Automatic Transmission 6R60, Four-Wheel Drive (Full Time) (Left Hand Drive), Four-Wheel Drive (Part Time) (Left Hand Drive), Four-Wheel Drive (Part Time) (Right Hand Drive), Left Hand Drive, Rear-Wheel Drive (Left Hand Drive)
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Mercury Mountaineer Temperature Sender Assembly
Part Number: F1SZ-10884-A
$34.68 MSRP: $56.18
You Save: $21.50 (39%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Sender Assy - Temperature
- Replaces: DOWY-10884-A
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 1997-2001 Mercury Mountaineer | 6 Cyl 4.0L, 8 Cyl 5.0L | 4AT 4R70W, 5AT 5R55E
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Mercury Mountaineer Sender Assembly
Part Number: 3L8Z-12A648-A
$29.19 MSRP: $47.29
You Save: $18.10 (39%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Sender Assy
- Replaces: 3L8Z-12A648-BA, DY-1004
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2002-2010 Mercury Mountaineer | 6 Cyl 4.0L SOHC EFI | 5-Speed Automatic Transmission 5R55S, 5-Speed Automatic Transmission 5R55W, 5-Speed Manual Transmission (M5R4), 6-Speed Automatic Transmission (6R80), 6-Speed Automatic Transmission 6R60, Four-Wheel Drive (Full Time) (Left Hand Drive), Four-Wheel Drive (Part Time) (Left Hand Drive), Four-Wheel Drive (Part Time) (Right Hand Drive), Left Hand Drive, Rear-Wheel Drive (Left Hand Drive)
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Mercury Mountaineer Sender Assembly
Part Number: F5AZ-12A648-AB
$20.98 MSRP: $34.00
You Save: $13.02 (39%)
Ships in 1 Business Day
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Product Specifications
- Other Name: Sender Assy
- Replaced by: 3F1Z-12A648-A
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2006-2010 Mercury Mountaineer | 8 Cyl 4.6L | 5-Speed Automatic Transmission 5R55S, 5-Speed Automatic Transmission 5R55W, 5-Speed Manual Transmission (M5R4), 6-Speed Automatic Transmission (6R80), 6-Speed Automatic Transmission 6R60, Four-Wheel Drive (Full Time) (Left Hand Drive), Four-Wheel Drive (Part Time) (Left Hand Drive), Four-Wheel Drive (Part Time) (Right Hand Drive), Left Hand Drive, Rear-Wheel Drive (Left Hand Drive)
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Mercury Mountaineer Sender Assembly
Part Number: F8CZ-12A648-B
$22.41 MSRP: $36.55
You Save: $14.14 (39%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: Sender Assy; Coolant Temperature Sensor, Temperature Sensor
- Replaces: F8CZ-12A648-AA, F77Z-12A648-AA, DY-824
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 2006-2010 Mercury Mountaineer | 6 Cyl 4.0L SOHC EFI | 5-Speed Automatic Transmission 5R55S, 5-Speed Automatic Transmission 5R55W, 5-Speed Manual Transmission (M5R4), 6-Speed Automatic Transmission (6R80), 6-Speed Automatic Transmission 6R60, Four-Wheel Drive (Full Time) (Left Hand Drive), Four-Wheel Drive (Part Time) (Left Hand Drive), Four-Wheel Drive (Part Time) (Right Hand Drive), Left Hand Drive, Rear-Wheel Drive (Left Hand Drive)
- 1998-2001 Mercury Mountaineer | 6 Cyl 4.0L | 4AT 4R70W, 5AT 5R55E
View related parts
Mercury Mountaineer Sender Assembly
Part Number: F77Z-12A648-AA
$22.41 MSRP: $36.55
You Save: $14.14 (39%)
Ships in 1-2 Business Days
ADD TO CART
Product Specifications
- Other Name: Sender Assy
- Replaced by: F8CZ-12A648-B
- Warranty: This genuine part is guaranteed by Ford's factory warranty.
Fits the following Vehicles:
- 1998-2001 Mercury Mountaineer | 6 Cyl 4.0L | 4AT 4R70W, 5AT 5R55E

Mercury Mountaineer Coolant Temperature Sensor

The Coolant Temperature Sensor for Mercury Mountaineer constantly measures the heat of the coolant, allowing the computer to maintain smooth driving. Every Mountaineer engine block has a small thermistor whose resistance varies in response to temperature changes. The signal to the Coolant Temperature Sensor goes straight to the engine control unit (ECU) that adjusts fuel delivery and spark timing in real time for efficiency and to avoid overheating. The Coolant Temperature Sensor provides quick feedback, allowing the engine to warm quickly or preventing the engine from running too hot once at operating temperature, protecting Mercury power and improving fuel economy. The robust solid state construction also appears in every production year of Mercury Mountaineer, so there aren't any different generations or styles to compare, just minor calibrations that do not affect how the part works. A faulty Coolant Temperature Sensor reading can cause rough idle or poor mileage and make the risk of engine damage significantly greater. This is due to how central it is to computer managed performance. Every Mercury Mountaineer is kept in its intended temperature range thanks to routine monitoring from this Coolant Temperature Sensor.

We provide a wide range of Mercury Mountaineer Coolant Temperature Sensor at the optimal prices. If you need Mercury Mountaineer Coolant Temperature Sensor, you can shop with confidence on our website. All our OEM parts come with a manufacturer's warranty and are delivered to your doorstep with a fast delivery service.

Mercury Mountaineer Coolant Temperature Sensor Parts Questions & Experts Answers

Sender Assembly
F5AZ-12A648-AB
Q: How to check and replace the coolant temperature sensor on the Mercury Mountaineer?
A:
The coolant temperature indicator system consists of a warning light or a temperature gauge on the dash and a coolant temperature-sending unit mounted on the engine. On the models covered, the Cylinder Head Temperature (CHT) sensor (V8 models)or Engine Coolant Temperature (ECT)sensor(V6 models), which is an information sensor for the Powertrain Control Module (PCM), also functions as the coolant temperature sending unit. If an overheating indication occurs check the coolant level in the system and make sure all connectors in the wiring harness between the sending unit and the indicator light or gauge are tight. When the ignition switch is turned to start and the starter motor is turning, the indicator light (if equipped) should come this doesn't mean the engine is overheated; it just means that the bulb is good. If the light doesn't come on when the ignition key is turned to START the bulb might be burned out, the ignition switch might be faulty or the circuit might be open. As soon as the engine starts, the indicator light should go out and remain off, unless the engine overheats. if the light doesn't go out, the wire between the sending unit and the light could be grounded, the sending unit might be defective, or the ignition switch might be faulty. Check the coolant to make sure it's correctly mixed; plain water. with no antifreeze, or coolant that's mainly water, might have too low a boiling point to activate the sending unit.