water leak- but cant find it!!!!!!!!!!!

[mitchell]

i currently have an issue with a water leak on my 98 wrx, the problem being that i cannot locate where the leak is. when the car sits idling there is no leakage, so cannot trace it that way, but the minute the car is taken out and driven the leakage occurs, as the minute the car is parked up then water drips from the car (drivers side of the car in the area of the front bumper) leaking only when under pressure. leakage does not appear to be coming from the engine itself. heres the good bit. so i drive the car, quickly get it back into the garage pop the bonnet to see if i can spot the leak, see no leak, but underside of the bonnet is soaking wet just in the region of the front light area. no water on the hoses or wet bits around the engine. the only thing that seems strange is that when looking down the back of the radiatior, the drain plug at the bottom(at least i think that is what it is) has a small upward facing pipe. this appears to be sealed. just above this and to the left sits a similar upward facing valve (cant tell if it is sealed) but it looks hollow. this seems the only place that the water can be being forced upwards onto the underside of the bonnet. should this be blocked or connected to something else or has anyone else experienced something similar.

thanks, martin  

[oz *sti*]

My radiator went last year - as you look in the engine bay it was the left hand side where the top pipe goes into the radiator it developed a hair line crack so when the car was sitting still there would be no leak but once the car is out running hot water flowing through the crack would expand with the heat and leave the front left hand side soaking wet with coolant over the left light and the air intak might be that mate.

If not sure there will be some more techie folk along with other thoughts.

[mitchell]

i will give it a look at tomorrow, was kinda expecting the pipes to be wet, but possibly the heat may dry the pipes quickly