Dissapearing coolant

[SSbeast]

I've got a VX SS 5.7 done around 100K. I seem to have an issue that around 500Ks i have to top the coolant up the coolant level light comes on. And it's pretty much consistant at around 500ks of normal driving. I've checked oil dilution and the oil level has never changed. Check trans level and the level and oil condition is fine. I've checked for radiatior and block leaks nothing. I've checked the exhaust i cause of cracked block or head gasket and no excessive steam, just the usual cold morning start and the only water in the tail pipe is from the cat. I just can't seem to see where the coolant is going. Anyone got any ideas? Cheers

[LightningVP]

By that you mean it's fully empty when the light comes on?

I would suggest filling the car, make sure you bleed it
a) Run the car for about 5-10 mins (or after you go for a drive...) Sit the car somewhere you can take note, and see if there are any leaks
b) Look around the engine bay for any white marks (when coolant dries it turns white), search everywhere, get a jack and search underneath as well...

[banga]

take the radiator fans out so that you can see the core and header plate (where the tubes meet the tank) look at the place where the tubes meet the alloy plate and see if you can see corrosion marks or leaks , also check where the plastic tank sits in the plate , if there is stains there it may need recrimping believe me its a lot easier to look at the whole radiator in car with the fan out 10 mil bolts are all that hold it in

[faroogoo]

Yeah hopefully its just a end tank o ring,worst case scenario it could be an electrolysis problem causing corrosion.