Porsche Cayenne & VW Touareg Petrol Low-Temperature Thermostats – 60°C Transmission & 70°C Engine (2002–2010)

Porsche Cayenne & VW Touareg Petrol Low-Temperature Thermostats — 60°C Transmission & 70°C Engine

A thermostat decides when your cooling system actually starts working. Most thermostats on the market only begin to open at around 80°C. Our transmission thermostat opens at 60°C and our engine thermostats open at 70°C, so transmission fluid and coolant are sent to the oil cooler and radiator much sooner, the whole system runs cooler, and you keep more thermal headroom for towing, sand, slow technical trails and hot climates.

Which Thermostat Do I Need?

How a Thermostat Works

Inside every thermostat is a sealed capsule filled with a temperature-sensitive wax. While the fluid is cold, a spring holds the valve shut and the fluid circulates in a short loop, bypassing the radiator or oil cooler so the engine or gearbox warms up quickly. As the fluid reaches the thermostat's rated temperature, the wax melts and expands, pushing a pin that opens the valve against the spring. Fluid is then routed through the radiator (engine) or the transmission oil cooler (gearbox), where heat is released. As temperature falls, the wax contracts and the spring closes the valve again — the thermostat constantly regulates flow to hold a stable operating temperature.

The opening temperature is the key number. A typical 80°C thermostat keeps the radiator or cooler bypassed until the fluid is already at 80°C. Our engine thermostats start opening about 10°C earlier at 70°C, and our transmission thermostat about 20°C earlier at 60°C — so cooling begins sooner and the whole system settles at a lower working temperature.

Specifications

Key Benefits

• Cooling starts much earlier. Engine thermostats open at 70°C and the transmission thermostat at 60°C, against the usual 80°C, so heat is moved out before it builds up
• Lower, more stable operating temperature. More margin before the temperature gauge climbs under tow, in sand or on long low-speed climbs
• Protects the transmission. Heat is what ages ATF and wears automatic gearboxes. At 60°C the transmission thermostat sends fluid to the oil cooler early, so ATF spends far less time running hot
• Unlocks your cooling upgrade. Lets the larger radiator and transmission oil cooler in our kit start working sooner instead of waiting behind an 80°C valve
• Less heat soak in hot climates. Lower baseline temperature means plastics, hoses and seals in the engine bay see less sustained heat
• Direct factory replacement. Fits in place of the original thermostat — no cutting, drilling or modification

Uses

• Completing the Overlandtrek Radiator & Transmission Oil Cooler Kit upgrade
• Overlanding, towing and carrying heavy loads
• Deep sand, desert driving and slow technical off-road trails
• Hot-climate daily driving and long highway climbs
• Replacing an aged or failing factory thermostat

Installation

• Difficulty: Intermediate — cooling system work
• Process: Drain the coolant (engine versions) or follow the ATF procedure (transmission version), remove the thermostat housing, swap the thermostat and seal, refit and refill
• Best time to fit: At the same time as the radiator and oil cooler kit — the system is already drained, so you only bleed and refill once
• After fitting: Bleed the cooling system properly — this platform is sensitive to trapped air. Use VW/Porsche G12/G13 specification coolant and check the ATF level at operating temperature

Frequently Asked Questions