Never remove the expansion tank filler cap when the engine is running, or has just been switched off, as the cooling system will be hot, and the consequent escaping steam and scalding coolant could cause serious injury. If the engine is hot, the electric cooling fan may start rotating even if the engine is not running, so be careful to keep hands, hair and loose clothing well clear when working in the engine compartment.
Cooling system draining
To drain the system, first remove the expansion tank filler cap. Place a thick cloth over the expansion tank cap, then turn the cap anti-clockwise as far as the first stop and wait for any pressure to be released, then depress it and turn it further anti-clockwise to remove it.
If additional working clearance is required, apply the handbrake, then jack up the front of the car and support it on axle stands.
Remove the radiator undershield, then place a large drain tray underneath, and unscrew the radiator drain plug
. Allow the coolant to drain into the tray. On completion, retighten the drain plug and refit the undershield. Where necessary, lower the car to the ground.
Remove the radiator undershield
Radiator drain plug
Cooling system flushing
If coolant renewal has been neglected, or if the antifreeze mixture has become diluted, then in time, the cooling system may gradually lose efficiency, as the coolant passages become restricted due to rust, scale deposits, and other sediment. The cooling system efficiency can be restored by flushing the system clean.
The radiator should be flushed independently of the engine, to avoid unnecessary contamination.
Disconnect the top and bottom hoses and any other relevant hoses from the radiator.
Insert a garden hose into the radiator top inlet. Direct a flow of clean water through the radiator, and continue flushing until clean water emerges from the radiator bottom outlet.
If after a reasonable period, the water still does not run clear, the radiator can be flushed with a good proprietary cleaning agent. It is important that the manufacturer’s instructions are followed carefully. If the contamination is particularly bad, remove the radiator, insert the hose in the radiator bottom outlet, and reverse-flush the radiator.
Remove the thermostat, then, if the radiator top hose has been disconnected from the engine, temporarily reconnect the hose.
With the top and bottom hoses disconnected from the radiator, insert a garden hose into the radiator top hose. Direct a clean flow of water through the engine, and continue flushing until clean water emerges from the radiator bottom hose.
On completion of flushing, refit the thermostat and reconnect the hoses.
If the correct specification anti-freeze is used, Jaguar state that the coolant only needs to be renewed every 5 years or 75 000 miles (vehicles upto 2006 model year) and 10 years or 150 000 miles (vehicles from 2006 model year), whichever is the sooner. The coolant must be renewed to provide the correct degree of protection.
The specified anti-freeze is of the Organic Acid Technology (OAT) type, and must not be mixed with any other type of anti-freeze
To give the recommended
mixture ratio for this antifreeze, 40% (by volume) of antifreeze must be mixed with 60% of clean, soft water
(see Haynes Hint)
It is rare to ever drain the cooling system completely – a small quantity will remain.If the system has been extensively flushed with clean water, this remaining quantity will in fact be plain water. For this reason,some people will first fill the system with the required quantity of neat antifreeze (half the total system capacity, for a 50% mixture), and then complete the filling process with plain water. This ensures that the resulting coolant (once it has mixed inside the engine) is not ‘diluted’by oil coolant or water remaining in the system.
||Motorcraft Super Plus 2000 antifreeze (orange) to Jaguar specification WSS-M97 B44
Before adding antifreeze, the cooling system should be completely drained, preferably flushed, and all hoses checked for condition and security. Fresh antifreeze will rapidly find any weaknesses in the system.
After filling with antifreeze, a label should be attached to the expansion tank, stating the type and concentration of antifreeze used, and the date installed. Any subsequent topping-up should be made with the same type and concentration of antifreeze. If topping-up using antifreeze to Jaguar’s specification, note that a 50/50 mixture is permissible, purely for convenience.
Cooling system filling
Before attempting to fill the cooling system, make sure that all hoses and clips are in good condition, and that the clips are tight. Note that an antifreeze mixture must be used all year round, to prevent corrosion of the engine components.
Remove the oil level dipstick, and filler cap, then pull the plastic cover upwards from the top of the engine
Pull the plastic cover upwards from its mountings
Disconnect the wiring from the mass air flow (MAF) sensor
Disconnect the mass airflow sensor wiring plug
Slacken the clamp and disconnect the air cleaner outlet hose
Release the clamp and disconnect the air outlet hose
Disconnect the wiring plug(s) (where fitted) at the rear of the air cleaner, and disconnect the vacuum hose
Disconnect the vacuum hose from the underside of the air cleaner housing
Disconnect the air intake pipe assembly at the front of the air cleaner
Disconnect the air intake pipes at the front of the air cleaner
Lift and remove the air cleaner assembly to release it from the rubber grommets
Pull the air cleaner assembly upwards from place
Undo the bolts and remove the air cleaner mounting bracket
. Unclip the wiring harness as the bracket is withdrawn.
Air filter mounting bracket bolts
Slacken the bleed screw at the top of the coolant pump
Bleed screw at the top of the coolant pump
Slowly fill the system until the coolant level bleed screw on the coolant pump. Tighten the bleed screw.
Continue to fill the system until it reaches the MAX mark on the side of the expansion tank.
Refit expansion tank filler cap.
Refit the mounting bracket, followed by the air cleaner assembly.
Start the engine and run it at fast idle speed (1500 rpm) for 20 seconds, then turn the engine off.
Unscrew the expansion tank cap, and fill the system to 15 mm above the MAX mark. Refit the cap.
Allow the engine to idle for 2 minutes. Monitor the coolant temperature gauge – if the engine starts to over-heat, turn the engine off immediately, and allow the engine to cool.
Raise the engine speed to 3000 rpm until the cooling fan operates, then turn off the engine and allow it to cool completely.
Remove the expansion tank cap and fill the system to the MAX mark.
If, after draining and refilling the system, symptoms of overheating are found which did not occur previously, then the fault is almost certainly due to trapped air at some point in the system, causing an airlock and restricting the flow of coolant; usually, the air is trapped because the system was refilled too quickly.
If an airlock is suspected, first try gently squeezing all visible coolant hoses. A coolant hose which is full of air feels quite different to one full of coolant, when squeezed. After refilling the system, most airlocks will clear once the system has cooled, and been topped-up.
While the engine is running at operating temperature, switch on the heater and heater fan, and check for heat output. Provided there is sufficient coolant in the system, any lack of heat output could be due to an airlock in the system.
Airlocks can have more serious effects than simply reducing heater output – a severe airlock could reduce coolant flow around the engine. Check that the radiator top hose is hot when the engine is at operating temperature – a top hose which stays cold could be the result of an airlock (or a non-opening thermostat).
If the problem persists, stop the engine and allow it to cool down
, before unscrewing the expansion tank filler cap or loosening the hose clips and squeezing the hoses to bleed out the trapped air. In the worst case, the system will have to be at least partially drained (this time, the coolant can be saved for re-use) and flushed to clear the problem.
Pressure cap check
Clean the pressure cap (expansion tank), and inspect the seal inside the cap for damage or deterioration. If there is any sign of damage or deterioration to the seal, fit a new pressure cap. If the cap is old, it is worth considering fitting a new one for peace of mind – they are not expensive. If the pressure cap fails, excess pressure will be allowed into the system, which may result in the failure of hoses, the radiator, or the heater matrix.