I installed a 180 deg thermostat in my car a couple of weeks ago and I cant get it to stop leaking around the area where the water neck meets the intake. I took it apart tonite and the o-ring was cut, but when I installed another one its trying to leak again. Did I install the o-ring wrong? Does it go under the thermostat between it and the intake or does it go on top of the thermostat between it and the water neck? Could I be tightning the bolts too much? PLease help. Thanks