: Water pouring out coolant cap, help please!

03-03-09, 09:16 PM
I have returned from a 5 mile or so trip several times now to have all my coolant come pouring out around the coolant cap all over the ground. This is a fairly new cap and I don't know what else to do. My mechanic has put a pressure pump to try to find leaks, even let it idle with the pressure tester on and no leaks. Does anyone know what the solution is? I've had the overheat light come on 2 times now as the reservoir drained out on the highway through the cap. There is no white smoke coming from the tail pipes, no head gasket leak. It's simply coming out of the top of the coolant reservoir and around the cap. And POURING out after running for 15 minutes or so. The fans are coming on fine too.


98 Catera
03-03-09, 09:42 PM
Thermostat not opening is my guess or air in the line somewhere or the system isn't completly full of coolant and when the thermostat does open in trys to push out all the air pockets in the cooling system. Maybe someone with more caddy knowledge might tell you something else.

03-04-09, 08:23 PM
Just because you don't have white smoke coming from exhaust does not rule out head gaskets. A small exhaust leak past the head gasket will force exhaust into cooling system causing it to pressurize and come out at weakest point (pressure cap). Open cap and smell for exhaust odor.