loss of coolant

[jaysto]

after a long run the engine coolant level light and message comes on........about every 3 weeks its taking about a cupfull of water .no signs of leaks and oil looks normal on the dipstick ?

[XjRestorations]

Hi,

Do you still have a plastic thermostat housing on the car do you know?
It is common for these to seep the smallest amount of water at the base of the housing.
Other common faults are hose clips that aren't lined up straight - again - allows the smallest amount of seepage.

Kind regards,
Keith

[jaysto]

have had a good look ,cant see any leaks.not sure about the thermostat housing...its a 2000 xkr ....seems to happen more often if i have sports mode pressed?

[XjRestorations]

The Sport mode should have no real bearing on it other than the car may be being 'used' more and therefore running a bit hotter.
The thermostat housing is black plastic as factory - a shiny aluminium version is the aftermarket upgrade.
The plastic ones often seep at the base of the mounting, so a small amount of water will leak into the centre of the Vee and evaporate. There is also a cooler hose that runs through the middle of the Vee - a small leak here will also leave no trace or puddle on the floor.
If you can have the cooling system pressure tested - that would determine the cause of the water leak.

[jaysto]

thank you

[mike020150]

I agree with Keith that if there are no other external leaks, the pipes running through the centre of the vee should be checked before moving on to think about the bigger issue of head gaskets. Unlike XK8s, XKRs don't have the plastic thermostat housing so that's one thing less likely to be leaking. Mike.

[jaysto]

just had the car serviced ,mechanic found a very small weep at the bottom of the rad .......costly .......but thank god it wasnt the head gasket