300SDL Coolant System Pressure Too High?
 

so my car was at the shop for heater/ac issues and the mechanic said the coolant system pressure was too high.

he couldn't figure out why, he put in a new thermostat, that didn't help. he thought it might be a water pump issue.

here's the real question, when I got it home I was losing water. through the overflow tube I think.

while trouble shooting I took the top radiator hose off. water was pumping out of the hose and radiator (two different directions) Is that normal?

I ran water from water hose into water tank to keep it all flowing and cool. and for several minutes..

should I just get a new radiator cap?

I hope he thinks the water pump is not pumping, therefore hot water in the engine is not getting to the radiator. me, i'd put a pressure tester on it and see how fast and how high the pressure rises and watch the temp on the motor and the rad. with a laser, then decide. a new cap is cheap, but usually when the fail, they won't hold pressure. maybe get a 2nd opinion? could be a head gasket or cyl. head problem. good luck, chuck.

I thought head gasket too, but shouldn't water be coming out the side or into the oil if it was a head gasket?

a leak into the cylinder is also possible. any steam out the tailpipe? good leak, chuck.