Parts for your 1987 Mitsubishi Pajero-Temperature sensors

1987 Mitsubishi Pajero Temperature Sensors

Temperature sensors are absolutely used on the 1987 Mitsubishi Pajero. Factory documentation such as the Mitsubishi Pajero/Montero Factory Service Manual (1982–1991, Engine and Electrical sections), Gregory’s Pajero 1983–1991 workshop manual, the Haynes Montero/Shogun 1983–1994 manual, and Mitsubishi’s ASA electronic parts catalogue all show multiple temperature-related devices on first‑gen Pajeros. Depending on engine (2.6L 4G54 petrol, 2.5L 4D56 turbo‑diesel, and market variants), these include a coolant temperature sender for the dash gauge, an engine coolant temperature (ECT) sensor for engine management or glow control, and thermo-switches for radiator or A/C condenser fans.

On a hard‑working 1987 Pajero, temperature sensors do plenty of quiet heavy lifting. The coolant temp sender keeps the dash gauge honest so the driver can spot overheating before it turns costly. The ECT sensor feeds the ECU (on EFI petrol) or the glow/control system (on diesel), helping with cold starts, idle quality, fuelling, and timing. Many models also have a fan thermo‑switch that kicks auxiliary fans in when the coolant gets hot, especially handy crawling up a rutted track on a 35‑degree arvo.

There isn’t a strict replacement interval for these sensors—they’re usually swapped when faulty. Typical clues they’re on the way out include hard cold starts, a gauge that reads weird, fans running when they shouldn’t, rough idle, rich running, or higher fuel use. Because the Pajero’s alloy housings and old connectors can be a bit precious after decades, gentle handling matters.

• Inspection: At service time, check for brittle plugs, green corrosion on terminals, and coolant stains around the sensor threads or housing.
• Testing: Use a multimeter to measure resistance of the ECT or thermo‑switch against the temperature specs in a workshop manual. For the gauge sender, confirm the dash reading tracks a known temperature (an infrared thermometer on the thermostat housing helps).
• Replacement tips: Work on a cold engine, depressurise the cooling system, and catch any spills. Replace sealing washers/O‑rings, and use the correct thread sealant if specified in the manual—avoid over‑tightening into alloy.
• Cooling system health: Sensors only report what they see. Fresh coolant at the right mix, a sound radiator cap, and a clear radiator keep readings accurate and stable.
• Diesel specifics: Glow‑related temperature sensors are vital for clean cold starts. If starts are smoky or lumpy on frosty mornings, test the temp sensor before throwing glow plugs at it.

For location, most petrol 4G54 setups place the gauge sender and ECT on or near the thermostat housing/water outlet. On 4D56 diesels, look on the cylinder head or thermostat housing. When in doubt, follow the manual’s diagrams—the sources above map them clearly for the 1987 model year.

Popular questions about 1987 Mitsubishi Pajero temperature sensors

Do early Pajeros have more than one temperature sensor?
Yes. Most 1987 models use a separate sender for the dash gauge, an ECT sensor for engine control/glow logic, and often a thermo‑switch for an electric fan. The exact combo depends on engine and market equipment, but the factory manuals and parts catalogues show multiple temp‑related devices on these vehicles.

Where is the coolant temperature sensor located?
On the 2.6L petrol (4G54), it’s typically screwed into or near the thermostat housing/water outlet on the intake side. On the 2.5L turbo‑diesel (4D56), expect it on the cylinder head or the thermostat housing area. The gauge sender and ECT are separate pieces, usually close to each other.

How do you test a suspect temperature sensor?
Use a multimeter to measure resistance across the sensor as the engine warms, then compare to the resistance‑vs‑temperature chart in a workshop manual. For a fan thermo‑switch, confirm it closes at the specified temperature. For the dash sender, verify the gauge reading aligns with a measured surface temperature at the housing.