How to service the Oil Pressure Switch on Mercury Cougar?

The service process of the oil pressure switch starts with disconnecting the battery ground cable. Raise the vehicle before performing support functions. To operate on the oil pressure switch, you need to disconnect the electric connection then take out the oil pressure switch. Reverse the installation process to service the oil pressure switch unit.

How to Service the Engine Oil Pressure Switch on Mercury Mariner?

Start the Engine Oil Pressure (EOP) switch service by hoisting the vehicle to a position while keeping it in the neutral gear. The service requires removal of the five bolts and the pin-type retainer and the right-hand splash shield. The service requires removal of the EOP switch electrical connector and thereafter removal of the switch always applying thread sealant to the switch threads before replacement. The EOP switch should be tightened to 15 Nm (133 lb-in) before reconnecting the electrical connector. Reinstall the splash shield by securing its five bolts at 9 Nm torque.

OEM Mercury Oil Pressure Switch

Oil Pressure Sender Switch

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17 Oil Pressure Switches found

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Mercury Oil Pressure Sensor Part Number: GC3Z-9278-B
$20.80 MSRP: $32.18
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Product Specifications
- Other Name: Switch Assembly - Oil Pressure; Engine Oil Pressure Switch; Oil Pressure Gauge Sw; Pressure Switch; Oil Pressure Switch; Pressure Sensor; Sending Unit; Switch Assembly; Oil Gauge
- Replaces: 6U5Z-9278-D, 1U5Z-9278-DA, GC3Z-9278-A, SW-6357
Fits the following Mercury Models:
- Grand Marquis | 2000-2011 | GS, GSL, Limited Edition, LS, LSE, Ultimate Edition | 8 Cyl 4.6 L FLEX, 8 Cyl 4.6 L GAS
- Marauder | 2003-2004 | Base | 8 Cyl 4.6 L GAS
- Mountaineer | 1999-2010 | Base, Convenience, Luxury, Premier | 6 Cyl 4.0 L GAS, 8 Cyl 4.6 L GAS, 8 Cyl 5.0 L GAS
- Sable | 2008-2009 | Base, Premier | 6 Cyl 3.5 L GAS
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Mercury Pressure Switch, Green Part Number: BE8Z-9278-A
$16.03 MSRP: $25.45
You Save: $9.42 (38%)
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Product Specifications
- Other Name: Switch Assembly - Oil Pressure; Engine Oil Pressure Switch; Oil Pressure Sending Unit; Switch; Oil Pressure Switch
- Replaces: 1S7Z-9278-AA, SW-6682
Fits the following Mercury Models:
- Mariner | 2005-2008 | Base, Convenience, Hybrid | 4 Cyl 2.3 L FULL HYBRID EV-GAS (FHEV), 4 Cyl 2.3 L GAS
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Mercury Pressure Switch Part Number: G1CZ-9278-B
$24.73 MSRP: $39.27
You Save: $14.54 (38%)
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Product Specifications
- Other Name: Switch Assembly - Oil Pressure; Engine Oil Pressure Switch; Oil Pressure Sending Unit; Oil Pressure Switch
- Replaces: 1U5Z-9278-GA, SW-6376, 6U5Z-9278-G, G1CZ-9278-A
Fits the following Mercury Models:
- Mariner | 2009-2011 | Base, Hybrid, Premier | 4 Cyl 2.5 L FULL HYBRID EV-GAS (FHEV), 4 Cyl 2.5 L GAS
- Milan | 2006-2011 | Base, Hybrid, Premier | 4 Cyl 2.3 L GAS, 4 Cyl 2.5 L FULL HYBRID EV-GAS (FHEV), 4 Cyl 2.5 L GAS
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Mercury Oil Pressure Sending Unit Part Number: D4AZ-9278-A
$45.08 MSRP: $72.73
You Save: $27.65 (39%)
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Product Specifications
- Other Name: Switch Assembly - Oil Pressure; Engine Oil Pressure Switch; Oil Pressure Gauge Sw; Oil Pressure Switch; Oil Gauge; Oil Gauge Sending Unit
Fits the following Mercury Models:
- Colony Park | 1987-1991 | GS, LS | 8 Cyl 5.0 L GAS
- Cougar | 1984-1997 | Base, LS, XR-7 | 4 Cyl 2.3 L GAS, 6 Cyl 3.8 L GAS, 8 Cyl 4.6 L GAS, 8 Cyl 5.0 L GAS
- Grand Marquis | 1984-1991 | Base, Colony Park, GS, LS | 8 Cyl 5.0 L GAS
- Lynx | 1984-1987 | Base, GL, GS, L, LS, LTS, RS, XR3 | 4 Cyl 1.6 L GAS, 4 Cyl 1.9 L GAS
- Marquis | 1984-1986 | Base, Brougham | 4 Cyl 2.3 L GAS, 4 Cyl 2.3 L LPG, 6 Cyl 3.8 L GAS
- Mountaineer | 1997-1998 | Base | 6 Cyl 4.0 L GAS, 8 Cyl 5.0 L GAS
- Mystique | 1995-2000 | Base, GS, GS Spree, LS, LS Young America | 6 Cyl 2.5 L GAS
- Sable | 1986-1995 | GS, LS, LTS | 4 Cyl 2.5 L GAS, 6 Cyl 3.0 L GAS, 6 Cyl 3.8 L GAS
- Topaz | 1984-1994 | Base, GS, GS AWD, LS, LS AWD, LTS, LTS AWD, Sport, Sport AWD, XR5, XR5 AWD | 4 Cyl 2.3 L GAS, 6 Cyl 3.0 L GAS
- Tracer | 1991-1999 | Base, GS, LS, Trio | 4 Cyl 1.9 L GAS, 4 Cyl 2.0 L GAS
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Mercury Oil Pressure Switch Part Number: E4ZZ-9278-A
$21.53 MSRP: $34.18
You Save: $12.65 (38%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Sender Assembly - Oil Pressure; Engine Oil Pressure Switch; Oil Pressure Gauge Sw; Oil Pressure Sending Unit
Fits the following Mercury Models:
- Cougar | 1984-1988 | Base, LS, XR-7 | 4 Cyl 2.3 L GAS, 6 Cyl 3.8 L GAS, 8 Cyl 5.0 L GAS
- Marquis | 1984-1986 | Base, Brougham | 4 Cyl 2.3 L GAS, 4 Cyl 2.3 L LPG, 6 Cyl 3.8 L GAS
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Mercury Oil Pressure Switch Part Number: E9SZ-9278-A
$11.72 MSRP: $18.91
You Save: $7.19 (39%)
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Product Specifications
- Other Name: Switch Assembly - Oil Pressure; Engine Oil Pressure Switch; Oil Pressure Gauge Sw; Oil Pressure Sending Unit; Oil Gauge Sending Unit
- Replaces: F4TZ-9278-A
Fits the following Mercury Models:
- Cougar | 1989-1997 | LS, XR-7 | 6 Cyl 3.8 L GAS, 8 Cyl 4.6 L GAS
- Grand Marquis | 1992-1999 | GS, LS | 8 Cyl 4.6 L GAS
- Mountaineer | 1997-1998 | Base | 6 Cyl 4.0 L GAS, 8 Cyl 5.0 L GAS
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Mercury Oil Pressure Sending Unit Part Number: F5RZ-9278-A
$7.94 MSRP: $10.80
You Save: $2.86 (27%)
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Product Specifications
- Other Name: Switch Assembly - Oil Pressure; Engine Oil Pressure Switch; Oil Gauge Sending Unit
Fits the following Mercury Models:
- Mystique | 1995-1999 | Base, GS, GS Spree, LS | 4 Cyl 2.0 L GAS
- Sable | 1996 | G, GS, LS | 6 Cyl 3.0 L GAS
- Tracer | 1998-1999 | GS, LS, Trio | 4 Cyl 2.0 L GAS
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Mercury Oil Pressure Sending Unit Part Number: XS2Z-9278-AA
$2.05 MSRP: $3.31
You Save: $1.26 (39%)
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Product Specifications
- Other Name: Switch Assembly - Oil Pressure; Engine Oil Pressure Switch
- Replaces: XS2Z-9278-CA
Fits the following Mercury Models:
- Cougar | 1999-2002 | Base | 4 Cyl 2.0 L GAS
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Mercury Pressure Switch Part Number: 6U5Z-9278-M
$102.89 MSRP: $172.73
You Save: $69.84 (41%)
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Product Specifications
- Other Name: Switch Assembly - Oil Pressure; Engine Oil Pressure Switch; Oil Pressure Gauge Sw; Oil Pressure Switch; Oil Pressure Sending Unit; Oil Gauge Sending Unit
- Manufacturer Note: 3/8" NPTF
- Replaces: 1U5Z-9278-BA, 6U5Z-9278-L, SW-6362
Fits the following Mercury Models:
- Cougar | 1999-2002 | Base, S, V6 | 6 Cyl 2.5 L GAS
- Mariner | 2005-2008 | Base, Premier | 6 Cyl 3.0 L GAS
- Montego | 2005-2007 | Luxury, Premier | 6 Cyl 3.0 L GAS
- Sable | 1999-2005 | GS, LS, LS Premium, Platinum Edition | 6 Cyl 3.0 L GAS
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Mercury Pressure Switch Part Number: 6U5Z-9278-A
$126.36 MSRP: $212.73
You Save: $86.37 (41%)
Ships in 1-2 Business Days
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Product Specifications
- Other Name: Switch Assembly - Oil Pressure; Oil Pressure Switch; Oil Pressure Sending Unit; Oil Gauge Sending Unit
- Replaces: 1U5Z-9278-AA, F8AZ-9278-AA
Fits the following Mercury Models:
- Sable | 1999-2005 | GS, LS, LS Premium, Platinum Edition | 6 Cyl 3.0 L GAS
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Mercury Oil Pressure Sending Unit Part Number: F3XY-9278-B
$24.37 MSRP: $33.16
You Save: $8.79 (27%)
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Product Specifications
- Other Name: Switch Assembly - Oil Pressure; Engine Oil Pressure Switch; Oil Pressure Light Sw
- Manufacturer Note: #25240,89920
Fits the following Mercury Models:
- Villager | 1993-2002 | Base, Estate, GS, LS, Nautica, Sport | 6 Cyl 3.0 L GAS, 6 Cyl 3.3 L GAS
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Mercury Oil Pressure Sending Unit Part Number: E9BZ-9278-A
$19.43 MSRP: $26.44
You Save: $7.01 (27%)
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Product Specifications
- Other Name: Switch Assembly - Oil Pressure; Engine Oil Pressure Switch
Fits the following Mercury Models:
- Tracer | 1991 | LTS | 4 Cyl 1.8 L GAS
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Mercury Oil Pressure Sending Unit Part Number: XS2Z-9278-CA
$2.08 MSRP: $3.31
You Save: $1.23 (38%)
ADD TO CART
Product Specifications
- Other Name: Switch Assembly - Oil Pressure; Engine Oil Pressure Switch
- Replaced by: XS2Z-9278-AA
Fits the following Mercury Models:
- Mystique | 2000 | GS | 4 Cyl 2.0 L GAS
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Mercury Pressure Switch Part Number: 6U5Z-9278-N
$129.29 MSRP: $212.73
You Save: $83.44 (40%)
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Product Specifications
- Other Name: Switch Assembly - Oil Pressure; Engine Oil Pressure Switch; Oil Pressure Sending Unit; Oil Pressure Switch
- Replaces: SW-6356, 6U5Z-9278-J
Fits the following Mercury Models:
- Mariner | 2008-2011 | Base, Premier | 6 Cyl 3.0 L FLEX, 6 Cyl 3.0 L GAS
- Milan | 2006-2011 | Base, Premier | 6 Cyl 3.0 L FLEX, 6 Cyl 3.0 L GAS
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Mercury Oil Pressure Sending Unit Part Number: D2AZ-9278-AA
Product Specifications
- Other Name: Switch Assembly - Oil Pressure; Engine Oil Pressure Switch; Oil Pressure Gauge Sw; Oil Gauge Sending Unit
Fits the following Mercury Models:
- Cougar | 1999 | V6 | 6 Cyl 2.5 L GAS
- Sable | 1996-1998 | G, GS, LS, LS Premium | 6 Cyl 3.0 L GAS
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Mercury Belt Tensioner Part Number: E9ZZ-9278-A
Product Specifications
- Other Name: Switch Assembly - Oil Pressure; Serpentine Belt Drive Kit; Oil Pressure Sending Unit; Serpentine Tensioner
Fits the following Mercury Models:
- Capri | 1985-1986 | 5.0, RS | 8 Cyl 5.0 L GAS
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Mercury Oil Pressure Sending Unit Part Number: 6U5Z-9278-K
Product Specifications
- Other Name: Switch Assembly - Oil Pressure; Engine Oil Pressure Switch
- Replaces: 1U5Z-9278-FA
Fits the following Mercury Models:
- Monterey | 2004-2007 | Base, Convenience, Luxury, Premier | 6 Cyl 4.2 L GAS

Mercury Oil Pressure Switch

OEM Oil Pressure Switch boasts unmatched quality. Each part goes through full quality checks. They adhere to Mercury's official factory standards. These steps remove flaws and inconsistencies. So you can get Oil Pressure Switch with long life and a perfect fit. Come to our website and find genuine Mercury parts. We keep a wide inventory of OEM parts at the highly affordable prices. It's easy to search, compare, and pick what you need. You'll love the clear info and simple checkout. We offer top-rated customer service, and we reply fast. We also ship promptly to ensure your order arrives on time.

Mercury Oil Pressure Switch Parts and Q&A

Pressure Switch
6U5Z-9278-M
Q: How to service the Oil Pressure Switch on Mercury Cougar?
A:
The service process of the oil pressure switch starts with disconnecting the battery ground cable. Raise the vehicle before performing support functions. To operate on the oil pressure switch, you need to disconnect the electric connection then take out the oil pressure switch. Reverse the installation process to service the oil pressure switch unit.
Pressure Switch
G1CZ-9278-B
Q: How to Service the Engine Oil Pressure Switch on Mercury Mariner?
A:
Start the Engine Oil Pressure (EOP) switch service by hoisting the vehicle to a position while keeping it in the neutral gear. The service requires removal of the five bolts and the pin-type retainer and the right-hand splash shield. The service requires removal of the EOP switch electrical connector and thereafter removal of the switch always applying thread sealant to the switch threads before replacement. The EOP switch should be tightened to 15 Nm (133 lb-in) before reconnecting the electrical connector. Reinstall the splash shield by securing its five bolts at 9 Nm torque.