Date of issue 2/98 Bulletin Number 303-14 Page 1 of 3
2/98V8 XJ Series/XK8
1997 MY-ON XK8 Range
1998 MY-ON V8 XJ Series
Low Coolant Level –
Warning Lamp Illuminated
When a new vehicle is factory-filled with antifreeze solution, small pockets of air may remain
trapped in the cooling system. On a new vehicle, these pockets of air may take some considerable
time to be purged, resulting in a gradual drop in the coolant level. This process may eventually
lead to illumination of the coolant warning lamp by the low level sensor located in the coolant
Once the coolant level has dropped, it is also possible that the captive float which actuates the
low level sensor may stick in the down position, leaving a warning on even after the cooling
system has been refilled.
When investigating a customer complaint of low coolant level warning light remaining on
proceed as follows:
A. TOPPING-UP THE COOLING SYSTEM.
The following procedure assumes that only a minor top-up of the coolant is required - a
maximum of 1 quart of coolant. Any causes of major leakage must be repaired before continuing.
1. With the engine cold, remove the pressure cap from the coolant reservoir. Check the
pressure cap seal - replace if necessary. Visually check the coolant level. If low,
continue with the procedure below.
2. If the coolant level is below the bottom of the filler neck, top up with Jaguar Antifreeze
D542 (diluted 50:50 with clean water) until the coolant rises to the bottom of the filler neck.
3. Start the engine and allow it to run at idling speed. The coolant level may fall in the coolant
reservoir. With the engine still running, immediately top up the coolant to thebottom of the
4. Before the coolant temperature has a chance to increase, fully tighten the pressure cap on the
5. Before stopping the engine, check that the coolant warning lamp is off.