Jaguar XK8 - Early Water Pump Part Problems and How to Resolve Them

As with all auto engines, severe overheatingreplacing the water pump, with a cold engine, take
problems can be very frustrating and nervethe filler cap off the expansion tank and then ask
racking especially in hot weather and slow movingsomeone to run the engine for you at 1200 rpm.
traffic. If not resolved it can be potentially veryShould the pump be working correctly, water
expensive! It's critical to ensure your XK8 coolingshould be circulating / swirling well in the tank. If
system parts are in tip top order for piece ofthere is a problem, then there will be very little
mind. Worse case severe overheating scenariosswirl and therefore indicative of a problem with
are; blown head gaskets, damaged cylinder headsthe water pump. If you are going to the effort of
and potentially a deterioration in engine lubricationchecking it then it's worth replacing with the latest
quality. The latter can then affect the longevity ofXK8 parts including water pump and other cooling
crankshaft bearings and the general life of thesystem parts.
XK8 engine.Pre 2003 cars also suffered from breakdown of
Prior to 2003 and the introduction of the 4.2 XKother plastic cooling system parts. These relate to
engines, earlier cars suffered from using poorthe thermostat housing rising out of the block and
quality parts in the form of lightweight materials.the bridge pipe linking the cylinder heads on
Relating to the water pump, this manifests itself innaturally aspirated cars (the XKR has an alloy
the disintegration / breaking up of the plasticpipe). The thermostat housings are now available
impellor within the water pump. This then leads toin alloy and we hope that the bridge pipe will
reduced coolant flow, localised heating and thefollow. The Jaguar Part number for the water
worst case problems mentioned above. Indicativepump is - AJ8008912 and all later water pumps
signs of a cooling problem on the XK8 engine aresupersede to this part number.
the cooling fans staying on for long periodsIf you are going to the trouble of the above then
regardless of temperature and / or one of thewe recommend you change the thermostat and
top hoses blowing off.check / replace all hoses as required.
Before going to the effort of removing /