OEM Replacement Compatibility

This thermostat is designed as a direct replacement for multiple Mitsubishi OEM part numbers:

OEM Part Numbers

• MD315301
• MD310106
• MD335170
• MD337408
• MD338234
• MD175746

Matching OEM specifications helps ensure proper fitment and cooling system performance.

Vehicle Applications

This thermostat fits numerous Mitsubishi diesel applications powered by the popular 2.5L turbo diesel engine.

Mitsubishi Colt / Rodeo

• 1996-2007 Mitsubishi Colt 2.5D
• 1996-2007 Mitsubishi Colt 2.5 TD 4WD
• 2001-2007 Mitsubishi Colt 2.5 TD High Output Models

Mitsubishi Pajero Classic

• 2002+ Mitsubishi Pajero Classic 2.5 TD

Mitsubishi Pajero II

• 1990-1999 Mitsubishi Pajero II 2.5 TD 4WD

Mitsubishi Pajero Sport

• 1998+ Mitsubishi Pajero Sport 2.5 TD
• 2002+ Mitsubishi Pajero Sport 2.5 TD 85HP
• 2003+ Mitsubishi Pajero Sport 2.5 TD 98HP

Mitsubishi Shogun II

• 1990-2000 Mitsubishi Shogun II 2.5 TD 4WD

Mitsubishi Shogun III

• 2000-2006 Mitsubishi Shogun III 2.5 TDi
• 2001-2006 Mitsubishi Shogun III 2.5 TDi High Output Models

Always verify your VIN, engine code, and OEM part number before ordering.

Common Signs of a Bad Thermostat

A failing thermostat often gives warning signs before complete failure.

Engine Overheating

One of the most common symptoms occurs when the thermostat becomes stuck closed, restricting coolant flow.

Temperature Gauge Fluctuations

Rapid swings in engine temperature can indicate inconsistent thermostat operation.

Poor Heater Performance

A thermostat stuck open may prevent the engine from reaching proper operating temperature.

Increased Fuel Consumption

Diesel engines running too cool often experience reduced efficiency.

Coolant Leaks Around Housing

Damaged seals or improper thermostat seating may allow coolant leakage.

Benefits of Replacing an Aging Thermostat

Many diesel owners focus on radiators, water pumps, and hoses while ignoring the thermostat.

Replacing a worn thermostat can:

• Improve engine reliability
• Reduce overheating risk
• Restore factory operating temperatures
• Improve winter warm-up times
• Reduce stress on the cooling system
• Help maximize fuel economy

Considering the relatively low cost of a thermostat compared to engine repairs, replacement is often cheap insurance.

Installation Recommendations

When replacing a thermostat, it’s smart to inspect the rest of the cooling system.

Recommended Maintenance

• Replace thermostat gasket or seal
• Inspect radiator hoses
• Check coolant condition
• Flush cooling system if needed
• Inspect radiator cap
• Verify water pump operation

These simple steps can prevent future cooling system failures.

Pros and Cons

Pros

• Direct OEM replacement
• Wide Mitsubishi diesel compatibility
• Supports proper operating temperatures
• Helps prevent overheating
• Affordable maintenance item
• Suitable for stock cooling systems

Cons

• Fitment varies by engine and market
• Cooling system inspection recommended during replacement
• Not designed as a performance thermostat

Final Verdict

The Mitsubishi MD315301 thermostat and its related OEM replacements provide a simple but essential solution for maintaining cooling system reliability in Mitsubishi diesel trucks and SUVs.

Whether you’re driving a Pajero, Shogun, Pajero Sport, or Colt/Rodeo, replacing a worn thermostat can help restore proper operating temperatures, improve reliability, and prevent costly engine damage.

For owners of Mitsubishi’s durable 2.5L diesel platforms, this thermostat remains one of the most important preventative maintenance components in the entire cooling system.