The cooling system

Keeping an E-Type cool in modern traffic is one of the common ownership preoccupations. The system is conventional in principle: a front-mounted radiator, a belt-driven water pump, a thermostat, a header tank and a fan arrangement to pull air through the core when the car is moving slowly. The weak points are usually condition and airflow, not the basic design.

The main components

• Radiator. The core needs to pass air and water freely. Bent fins, internal scale and external debris all reduce its capacity.
• Water pump. The impeller can corrode or slip on its shaft, and the bearing or seal can weep.
• Thermostat. A partially opening thermostat restricts flow and can cause the gauge to read high without the engine actually being overheated.
• Hoses and clamps. Bottom hoses can collapse internally with age, and leaks at the heater tap and connections are common.
• Fan and cowl. The fan should move enough air at idle; the cowl must be present and intact so air is pulled through the radiator rather than around it.

What Jaguar changed on Series 2

The Series 2 brought a larger front air intake and twin electric cooling fans. Those changes were a factory response to the cooling margin of the earlier cars in slow traffic. A Series 1 in good order can hold its temperature, but it has less reserve when the radiator is partly blocked, the fan is tired or the ignition timing is not right.

Where to start when the gauge climbs

Before fitting an aluminium radiator or an uprated fan, prove the standard system first. Check the fan runs, the thermostat opens, the water pump circulates, the core is clean and the cap holds pressure. Check the ignition timing and mixture, because an engine that is running poorly generates more heat. Only when the standard system is working as designed is an upgrade a sensible next step.

Routine care

Use the coolant concentration recommended for your climate, and check it with a hydrometer. Replace hoses that are hard, soft or bulging. Keep the header tank at the correct level and look for oil contamination or exhaust bubbles, either of which points at a more serious problem. A cooling system that is clean, pressurised and properly bled is more reliable than any single exotic component.