Quote Originally Posted by jick.cejoco View Post
which came first, the chicken or the egg? which came first, the hissing sound or the overheating? the only time overheating makes a hissing sound is when pressure is leaking from the pressure cap or some weak point that can not hold pressure. in this case, the leak must be visible. but a hissing sound that was caused by a vacuum leak will definitely cause overheating and lose coolant through the radiatior cap or overspills at the recovery bottle. stop guessing.use a vacuum gauge to see that you have engine vacuum between 17- 21 inches of mercury assuming your camshafts are OEM and that the engine is neither supercharged nor turbocharged. use diagnostic instruments to digitize your results and stay away from amateurs.
My mechanics did this. they closed the radiator properly with a new radiator cap... they also recommended lavramon for my radiator which I did. madumi na daw kasi.. baka daw kasi hindi nakalabas ng maaus pressure kaya nung minaneho ko ngang summer na sobrang init, naghanap ng ibang outlet ung excess pressure, leading to a the radiator cap leak. >.<