(Home) Losing coolant

Hi,I managed to borrow a rad cap off a neighbour and tried the cruiser out.Everything was checked,water,oil,etc and it was left to run until warmed up then turned off and left to cool.There had been a dramatic loss of coolant.So topped up and tried again,same thing.Had it sitting on dry concrete and there are no leaks.Four times this has been tried and each time there is no coolant left in the expansion tank.I recall reading either here or on Ace answers about erupting coolant from rad filler when car started without cap on.Yes it does.The engine starts on the button every time and sits ticking over with no flat spots.We've spent alot of time and a fair bit of money on this project but we are wondering if it is about time to cut our losses.
Sorry I should of mentioned it is a G reg 2.0 litre space cruiser.Any advise will be gratefully received,as was all the help given for my trouble with the rad cap.

- (#13893) Suresa, 24 Oct 04 08:29

The coolant is going somewhere and, if there are definitely no leaks under the vehicle, onto the dry concrete, you will have to consider that the coolant is crossing over from the engine block passages, into the combustion chambers. This is likely to mean a faulty head gasket or, a crack somewhere, possibly in the cylinder head itself. The "erupting" coolant, from the filler/rad cap, is a bad sign but, do check the exhaust, after the vehicles is warmed up, to see if there is any trace of steam of water droplets. You say that this loss is dramatic so, there should be quite a lot of steam or water droplets. Make sure the vehicle is warm, otherwise water droplets could be confused with condensation from the exhaust system.

- (#13893) John Davis (Leics), 24 Oct 04 11:02