How to remove and install a thermostat on Mitsubishi Lancer?

To remove and install the thermostat, with the engine cold remove the radiator cap and then drain the cooling system. For the 1.5-litre and 2.4-litre models disconnect the PCV hose, loosen the hose retaining clamps and pull off the air inlet hose; for the 2.4-litre, remove the air cleaner housing and air intake duct. Next, the hose clamp should be released and the upper radiator hose disconnected from the thermostat cover. The retaining bolts should be removed and the thermostat cover removed. Take note of the installed position, then remove the thermostat. In the case of the 1.8 and 2.0 litre models, release the hose clamp and take off the lower radiator hose from the thermostat cover. Remove the retaining bolts and the thermostat cover. Remove the thermostat, noting its installed position. A visual check can sometimes indicate whether the thermostat is still viable or not; for example, a thermostat with its valve fully opened after removal from a cold engine is obviously faulty and should therefore be replaced. Earlier, we removed Stage 1 to finally Stage 1, retaining bolts, and pay attention not to damage other components. The rest of the components to be removed varies with the engine. After the removal, we clean the mating surfaces of the thermostat cover and housing are clean and flat. The thermostat is installed in the same position as noted with the jiggle valve facing up. Finally, after tightening the retaining bolts to specification, the cooling system is refilled. To test the thermostat, check that the valve is fully closed when cold and then suspend and immerse with a reliable thermometer in a container of cold water (they should not touch the container). Heat the water gradually, observing thermometer reading, the valve should start to open at 82 ± 1.5°C. In order to verify that the thermostat valve opens at least 8.5 mm, heat the water to 95°C. If the en- opening temperature of the thermostat and valve lift are out of specification, the thermostat must be replaced. Check that the thermostat is fully closed when cooled below the valve opening temperature; if not, replace the thermostat.

What steps should be taken before assuming the thermostat is responsible for a cooling system issue on Mitsubishi Montero?

Prior to assuming that the thermostat is to blame for an issue with a cooling system, check the level of coolant, water pump, drivebelt tension, and temperature gauge operation. If your engine takes an excessive time to warm up, then your thermostat may be stuck open and need replacement. On the other hand, if the engine runs hot yet the upper radiator hose isn't hot, the thermostat may be stuck closed, not allowing coolant to escape to the radiator. This is a part that should to be replaced. Driving your vehicle without thermostat could cause poor emissions and bad fuel economy, so avoid doing that. The upper radiator hose is hot if coolant is flowing, indicating the thermostat is open. In order to change the thermostat, remove the negative battery cable and drain the cooling system, saving the coolant if in good condition. To locate the thermostat housing, follow the upper radiator hose to the engine. Loosen the clamp on the hose and take the hose off the fitting. If the hose is stuck, use these Channelock pliers to break the seal, or cut it off if it is old. Inspect the large fitting, if it corroded the cover for the thermostat housing may need to be replaced. You may need to tap it gently to loosen the housing cover after removing the bolts. Before you take it out, make a note of the orientation of the old thermostat, then clean the old gasket material from the housing and the cover. Install the new thermostat oriented with the correct end up. Apply RTV sealant to the new gasket and place it on the housing. Replace the cover and the bolts tightening them to the specified torque, reconnect the hose and tighten the clamp. To refill the cooling system, it is necessary to start the engine and test for leaks.

Genuine Mitsubishi Thermostat

Engine Coolant Thermostat

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17 Thermostats found

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Mitsubishi Thermostat Part Number: MQ701063
$44.30 MSRP: $61.53
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Product Specifications
- Other Name: Thermostat Kit
Fits the following Mitsubishi Models:
- Outlander | 2022-2025 | Black Edition, ES, SE, SE Launch Edition, SEL, SEL Launch Edition | 4 Cyl 2.5 L GAS
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Mitsubishi Thermostat Part Number: MD363571
$73.43 MSRP: $101.98
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Product Specifications
- Other Name: Thermostat Kit
Fits the following Mitsubishi Models:
- Lancer | 2006 | Evolution, Evolution MR, Evolution RS, Evolution SE | 4 Cyl 2.0 L GAS
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Mitsubishi Thermostat Part Number: 1305A803
$19.65 MSRP: $25.59
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Product Specifications
- Other Name: Thermostat Kit(87)
Fits the following Mitsubishi Models:
- Lancer | 2008-2017 | DE, ES, ES Sportback, GT, GT Sportback, GTS, GTS Sportback, Ralliart, Ralliart Sportback, SE, SEL | 4 Cyl 2.0 L GAS, 4 Cyl 2.4 L GAS
- Outlander | 2011-2020 | ES, LE, SE, SEL, SP | 4 Cyl 2.4 L GAS
- Outlander PHEV | 2018-2025 | ES, GT, LE, Platinum Edition, Ralliart, SE, SE Tech, SEL, SEL Premium, SEL Touring | 4 Cyl 2.0 L PLUG-IN HYBRID EV-GAS (PHEV), 4 Cyl 2.4 L PLUG-IN HYBRID EV-GAS (PHEV)
- Outlander Sport | 2011-2025 | BE, ES, GT, GT Special Edition, LE, Ralliart, S, SE, SE Special Edition, SEL, SP, Trail Edition | 4 Cyl 2.0 L GAS, 4 Cyl 2.4 L GAS
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Mitsubishi Thermostat Part Number: 1305A802
$20.58 MSRP: $26.81
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Product Specifications
- Other Name: Thermostat Kit, 82C
Fits the following Mitsubishi Models:
- Lancer | 2008-2015 | DE, ES, Evolution Final Edition, Evolution GSR, Evolution MR, Evolution MR Touring, Evolution SE, GTS, GTS Sportback, Ralliart, Ralliart Sportback, SE | 4 Cyl 2.0 L GAS, 4 Cyl 2.4 L GAS
- Outlander | 2008-2010 | ES, SE | 4 Cyl 2.4 L GAS
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Mitsubishi Thermostat Part Number: 1305A623
$21.93 MSRP: $28.55
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Product Specifications
- Other Name: Thermostat Kit
Fits the following Mitsubishi Models:
- Eclipse Cross | 2022-2025, 2018-2020 | Black Edition, ES, LE, Ralliart, SE, SE Special Edition, SEL, SEL Special Edition, SEL Touring, SP | 4 Cyl 1.5 L GAS
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Mitsubishi Thermostat Part Number: MD337408
$23.51 MSRP: $30.61
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Product Specifications
- Other Name: Thermostat Kit; Engine Coolant Thermostat
Fits the following Mitsubishi Models:
- Expo LRV | 1993-1994 | Base | 4 Cyl 1.8 L GAS
- Lancer | 2002-2007 | ES, LS, OZ Rally, SE | 4 Cyl 2.0 L GAS
- Mirage | 1993-2002 | DE, ES, LS | 4 Cyl 1.5 L GAS, 4 Cyl 1.8 L GAS
- Montero Sport | 1997-1999 | ES | 4 Cyl 2.4 L GAS
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Mitsubishi Thermostat Part Number: 1305A191
$24.50 MSRP: $31.90
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Product Specifications
- Other Name: Thermostat Kit; Engine Coolant Thermostat; Thermostat, Coolant
Fits the following Mitsubishi Models:
- Diamante | 1992-1996 | ES, LS | 6 Cyl 3.0 L GAS
- Montero | 2003-2006, 1994-1996 | LS, Limited, SR, XLS | 6 Cyl 3.0 L GAS, 6 Cyl 3.5 L GAS, 6 Cyl 3.8 L GAS
- Montero Sport | 1997-1998 | LS, XLS | 6 Cyl 3.0 L GAS
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Mitsubishi Thermostat Part Number: MD972903
$25.36 MSRP: $33.02
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Product Specifications
- Other Name: Thermostat Kit; Engine Coolant Thermostat; Thermostat, Coolant
Fits the following Mitsubishi Models:
- Cordia | 1984-1988 | Base, L, LS, Turbo | 4 Cyl 1.8 L GAS, 4 Cyl 2.0 L GAS
- Diamante | 1993-1996 | ES, LS | 6 Cyl 3.0 L GAS
- Eclipse | 1990-1994 | Base, GS | 4 Cyl 1.8 L GAS
- Expo | 1992 | Base, SP | 4 Cyl 2.4 L GAS
- Galant | 1985-1988 | Base, Sigma | 4 Cyl 2.4 L GAS, 6 Cyl 3.0 L GAS
- Mighty Max | 1984-1996 | 1 Ton, Base, S, SP, SPX, Sport | 4 Cyl 2.0 L GAS, 4 Cyl 2.4 L GAS, 4 Cyl 2.6 L GAS, 6 Cyl 3.0 L GAS
- Mirage | 1985-1996 | Base, ES, L, LS, RS, S, SE, Turbo, VL | 4 Cyl 1.5 L GAS, 4 Cyl 1.6 L GAS
- Montero | 1984-1994 | Base, LS, RS, SP, SR, Sport | 4 Cyl 2.6 L GAS, 6 Cyl 3.0 L GAS
- Sigma | 1989-1990 | Base | 6 Cyl 3.0 L GAS
- Starion | 1984-1989 | ES, ESi, ESi-R, LE, LS | 4 Cyl 2.6 L GAS
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Mitsubishi Thermostat Part Number: MD350415
$30.14 MSRP: $39.25
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Product Specifications
- Other Name: Thermostat Kit, 88C; Engine Coolant Thermostat
Fits the following Mitsubishi Models:
- Diamante | 1997-2004 | Base, ES, LS, VR-X | 6 Cyl 3.5 L GAS
- Eclipse | 2000-2005 | GT, GTS, Spyder GT, Spyder GTS | 6 Cyl 3.0 L GAS
- Endeavor | 2010-2011, 2004-2008 | LS, Limited, SE, XLS | 6 Cyl 3.8 L GAS
- Galant | 1999-2009 | ES, GTS, GTZ, LS, Ralliart, Sport V6 | 6 Cyl 3.0 L GAS, 6 Cyl 3.8 L GAS
- Montero | 1998-2000 | Base | 6 Cyl 3.5 L GAS
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Mitsubishi Thermostat Part Number: MD328070
$30.92 MSRP: $40.27
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Product Specifications
- Other Name: Thermostat Kit; Engine Coolant Thermostat; Thermostat, Coolant
Fits the following Mitsubishi Models:
- Eclipse | 2000-2005 | GS, RS, Spyder GS | 4 Cyl 2.4 L GAS
- Galant | 1999-2003 | DE, ES, LS | 4 Cyl 2.4 L GAS
- Outlander | 2003 | LS, XLS | 4 Cyl 2.4 L GAS
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Mitsubishi Thermostat Part Number: MN143463
$32.97 MSRP: $43.26
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Product Specifications
- Other Name: Thermostat Kit
Fits the following Mitsubishi Models:
- Lancer | 2003-2005 | Evolution, Evolution MR, Evolution RS | 4 Cyl 2.0 L GAS
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Mitsubishi Thermostat Part Number: 1305A239
$33.76 MSRP: $44.30
You Save: $10.54 (24%)
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Product Specifications
- Other Name: Thermostat Kit
Fits the following Mitsubishi Models:
- Montero | 2001-2002 | Limited, XLS | 6 Cyl 3.5 L GAS
- Montero Sport | 1999-2004 | ES, LS, Limited, XLS, XS | 6 Cyl 3.0 L GAS, 6 Cyl 3.5 L GAS
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Mitsubishi Thermostat Part Number: MD194988
$35.56 MSRP: $46.66
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Product Specifications
- Other Name: Thermostat Kit, 82C; Engine Coolant Thermostat; Thermostat, Coolant
Fits the following Mitsubishi Models:
- Diamante | 1997 | ES, LS | 6 Cyl 3.5 L GAS
- Eclipse | 2003-2012 | GT, GTS, SE, Spyder GT, Spyder GTS | 6 Cyl 3.0 L GAS, 6 Cyl 3.8 L GAS
- Galant | 2007-2009 | Ralliart | 6 Cyl 3.8 L GAS
- Montero | 1997 | LS, SR | 6 Cyl 3.5 L GAS
- Outlander | 2007-2020 | ES, GT, LS, XLS | 6 Cyl 3.0 L GAS
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Mitsubishi Thermostat Part Number: MD315301
$38.84 MSRP: $50.96
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Product Specifications
- Other Name: Thermostat Kit; Engine Coolant Thermostat
Fits the following Mitsubishi Models:
- Eclipse | 2006-2010, 1995-1999 | GS, GS Sport, GST, GSX, SE, Spyder GS, Spyder GST | 4 Cyl 2.0 L GAS, 4 Cyl 2.4 L GAS
- Expo | 1993-1995 | Base, SP | 4 Cyl 2.4 L GAS
- Expo LRV | 1993-1994 | Base, Sport | 4 Cyl 2.4 L GAS
- Galant | 2004-2010, 1993-1998 | DE, ES, GS, LS, S, SE, Sport Edition | 4 Cyl 2.0 L GAS, 4 Cyl 2.4 L GAS
- Lancer | 2004-2006 | Ralliart, Sportback, Sportback Ralliart | 4 Cyl 2.4 L GAS
- Outlander | 2004-2006 | LS, Limited, SE, XLS | 4 Cyl 2.4 L GAS
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Mitsubishi Thermostat Part Number: 1305A278
$40.50 MSRP: $53.15
You Save: $12.65 (24%)
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Product Specifications
- Other Name: Thermostat Kit; Engine Coolant Thermostat
Fits the following Mitsubishi Models:
- Eclipse | 2011-2012 | GS, GS Sport, SE, Spyder GS, Spyder GS Sport, Spyder SE | 4 Cyl 2.4 L GAS
- Galant | 2011-2012 | ES, FE, SE | 4 Cyl 2.4 L GAS
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Mitsubishi Thermostat Part Number: 1305A280
$27.47 MSRP: $35.77
You Save: $8.30 (24%)
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Product Specifications
- Other Name: Thermostat Kit, 87C
Fits the following Mitsubishi Models:
- Mirage | 2017-2024, 2014-2015 | BE, Black Edition, Carbonite Edition, DE, ES, GT, LE, RF, SE | 3 Cyl 1.2 L GAS
- Mirage G4 | 2017-2024 | BE, Carbonite Edition, ES, LE, RF, SE | 3 Cyl 1.2 L GAS
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Mitsubishi Thermostat Part Number: 1305A603
$33.11 MSRP: $43.45
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Product Specifications
- Other Name: Thermostat Kit
- Replaces: 1305A237
Fits the following Mitsubishi Models:
- 3000GT | 1991-1999 | Base, SL, Spyder SL, Spyder VR-4, VR-4 | 6 Cyl 3.0 L GAS

Mitsubishi Thermostat

The Mitsubishi Thermostat maintains the ideal engine temperature to ensure smooth and efficient drivability. Mitsubishi started life as a shipping company in 1870 but moved on to build the Model A sedan in 1917. This was an early example of bold ideas and solid craftsmanship at the firm. Equipped with responsive MIVEC engines and an excellent fuel saver, all the modern Mitsubishi engines produce just the right amount of power to ensure excellent performance in all situations. Super All Wheel Control is designed to improve traction on gravel, snow, and wet pavement, resulting in tremendously confident handling. Many drivers love the cruise control and smartphone link, while tests of future fuel cells offer greener journeys. Safety sensors add reassurance and are easy to live with. All these technologies manifest the brand objective of smart features, simple use, and a long-term reliable package that is suitable for families, commuters, and adventurers alike. In this system, the Thermostat applies a small spring-loaded valve that regulates the flow of coolant. Unlike the other controls, it does not respond to outside demands but rather reacts to heat. When the engine coolant is cold, the Thermostat remains closed. This helps the engine to warm up quickly. Further, it helps the engine oil achieve the right viscosity and thus cut down emissions. The valve opens and allows heat to flow to the radiator, thus preventing dangerous spikes in temperatures that could otherwise warp metal or waste fuel. When cycling open and closed on each trip, the Mitsubishi Thermostat contributes to stable combustion, reliable lubrication, and long life of the entire powertrain.

Pick genuine OEM Thermostat if you want superb performance and durability that lasts. Mitsubishi builds that using high-grade materials and official factory techniques to meet very strict standards. This means you get parts you can actually trust for your daily drive. Finding the right parts is simple in the massive stock of genuine inventory. You can stop guessing if a part will fit or hold up. You will love the low prices, dependable service and the real manufacturer's warranty on Mitsubishi Thermostat. Order today and the store will ship your brand-new items to your door as fast as possible.

Mitsubishi Thermostat Parts Questions & Experts Answers

Thermostat
MD315301
Q: How to remove and install a thermostat on Mitsubishi Lancer?
A:
To remove and install the thermostat, with the engine cold remove the radiator cap and then drain the cooling system. For the 1.5-litre and 2.4-litre models disconnect the PCV hose, loosen the hose retaining clamps and pull off the air inlet hose; for the 2.4-litre, remove the air cleaner housing and air intake duct. Next, the hose clamp should be released and the upper radiator hose disconnected from the thermostat cover. The retaining bolts should be removed and the thermostat cover removed. Take note of the installed position, then remove the thermostat. In the case of the 1.8 and 2.0 litre models, release the hose clamp and take off the lower radiator hose from the thermostat cover. Remove the retaining bolts and the thermostat cover. Remove the thermostat, noting its installed position. A visual check can sometimes indicate whether the thermostat is still viable or not; for example, a thermostat with its valve fully opened after removal from a cold engine is obviously faulty and should therefore be replaced. Earlier, we removed Stage 1 to finally Stage 1, retaining bolts, and pay attention not to damage other components. The rest of the components to be removed varies with the engine. After the removal, we clean the mating surfaces of the thermostat cover and housing are clean and flat. The thermostat is installed in the same position as noted with the jiggle valve facing up. Finally, after tightening the retaining bolts to specification, the cooling system is refilled. To test the thermostat, check that the valve is fully closed when cold and then suspend and immerse with a reliable thermometer in a container of cold water (they should not touch the container). Heat the water gradually, observing thermometer reading, the valve should start to open at 82 ± 1.5°C. In order to verify that the thermostat valve opens at least 8.5 mm, heat the water to 95°C. If the en- opening temperature of the thermostat and valve lift are out of specification, the thermostat must be replaced. Check that the thermostat is fully closed when cooled below the valve opening temperature; if not, replace the thermostat.
Thermostat
MD972903
Q: What steps should be taken before assuming the thermostat is responsible for a cooling system issue on Mitsubishi Montero?
A:
Prior to assuming that the thermostat is to blame for an issue with a cooling system, check the level of coolant, water pump, drivebelt tension, and temperature gauge operation. If your engine takes an excessive time to warm up, then your thermostat may be stuck open and need replacement. On the other hand, if the engine runs hot yet the upper radiator hose isn't hot, the thermostat may be stuck closed, not allowing coolant to escape to the radiator. This is a part that should to be replaced. Driving your vehicle without thermostat could cause poor emissions and bad fuel economy, so avoid doing that. The upper radiator hose is hot if coolant is flowing, indicating the thermostat is open. In order to change the thermostat, remove the negative battery cable and drain the cooling system, saving the coolant if in good condition. To locate the thermostat housing, follow the upper radiator hose to the engine. Loosen the clamp on the hose and take the hose off the fitting. If the hose is stuck, use these Channelock pliers to break the seal, or cut it off if it is old. Inspect the large fitting, if it corroded the cover for the thermostat housing may need to be replaced. You may need to tap it gently to loosen the housing cover after removing the bolts. Before you take it out, make a note of the orientation of the old thermostat, then clean the old gasket material from the housing and the cover. Install the new thermostat oriented with the correct end up. Apply RTV sealant to the new gasket and place it on the housing. Replace the cover and the bolts tightening them to the specified torque, reconnect the hose and tighten the clamp. To refill the cooling system, it is necessary to start the engine and test for leaks.