Parts for your 1986 Mitsubishi Pajero-Temperature sensors

1986 Mitsubishi Pajero temperature sensors — what they do and how to look after them

Technical references confirm the first‑gen (L040) 1986 Mitsubishi Pajero does use temperature sensors. The Mitsubishi Pajero/Montero Factory Service Manual (1982–1991) details an Engine Coolant Temperature (ECT) sensor for fuel and timing control on EFI petrol models, a single‑wire sender for the dash gauge, and coolant temperature inputs for diesel glow control. Gregory’s Manual No. 519 and the Mitsubishi ASA/CAPS parts catalogue also list part numbers for the ECT sensor, the gauge sender, and thermo‑fan/air‑con related switches on certain trims. So, temperature sensors are absolutely relevant and fitted on 1986 Pajero models.

On a 1986 Pajero, temperature sensors quietly keep things tidy under the bonnet. They feed the ECU (where fitted) with the engine’s coolant temperature so it can trim fuel and ignition when cold, run the choke strategy properly on EFI petrols, and prevent over‑fuelling once warm. Diesels rely on a coolant temp sensor to manage glow plug timing and cold‑start advance. There’s also a separate sender that drives the dash gauge, and in some specs a thermo switch cues auxiliary fans or air‑con cut‑out to keep temps in the green when you’re crawling a track in summer.

• Coolant temperature sensor (ECT) – EFI control and diesel glow strategy
• Temperature sender – feeds the dash gauge
• Thermo switch/sensor – fan or A/C logic on certain models

Servicing tips for the Pajero’s temperature sensors are straightforward and very DIY‑friendly:

• Check connectors first. The plugs near the thermostat housing cop heat and coolant vapour, clean green corrosion and use dielectric grease.
• Test before you toss. A typical ECT reads a few kilo‑ohms when cold and a few hundred ohms hot, wild jumps mean it’s cactus.
• Use proper coolant and keep it fresh. Old coolant is conductive and can skew readings and eat senders from the inside.
• If replacing, crack the sensor on a cold engine, catch the spill, and nip the new one up snug (about 15–20 N·m is common). Don’t drown threads in sealant, many sensors earth through the body.
• Bleed the cooling system and confirm the thermostat opens, a stuck stat can make a good sensor look bad.

Symptoms that point to sensor drama include hard cold starts, rich running, rough idle once warm, hunting glow times on diesels, or a dash gauge that’s lazy or pegged. Given the age of an ’86 rig, preventative replacement of a dodgy ECT and crusty sender during a cooling‑system refresh is cheap insurance before a long Kiwi or Aussie trip.

Popular questions

Where are the temperature sensors on a 1986 Pajero?
Most live around the thermostat housing on the cylinder head. You’ll usually find the two‑pin ECT (for ECU or glow control) and a single‑wire sender for the dash gauge there. Some trims also have a thermo switch on the radiator or in a coolant elbow for fan/A‑C logic.

Can a bad temperature sensor cause poor fuel economy?
Yep. If the ECT lies “cold,” the ECU enriches the mix like permanent warm‑up mode, chewing through fuel and washing bores. Diesels can over‑glow or advance oddly. Fixing the sensor often restores normal consumption and drivability.

Do carburetted 2.6‑litre models still have temperature sensors?
They don’t run an EFI ECT for fuelling, but they still have a sender for the dash gauge and may have thermo switches for fans or A/C cut‑out. Diesel variants retain a temp input for glow control regardless of carb vs EFI.