A good sized hole has formed at the clamp on my heater (assuming) hose that's attached at the rear of the intake manifold (by the distributor). That in itself is not the problem, the problem is why it formed. While it was shooting out at high pressure, my engine temp would cycle from 240 to 190ish, while normally when I have the fan turned on manually it stays at around 180. The water coming from the hole was mostly steam and very hot vapor, not pressure from the pump as it still escaped when the car was off for about 10 minutes. I got a new hose and clamps, but I'm afraid that either my thermostat or rad cap is causing pressure buildup, or worse, something is blocking the flow of coolant in the intake manifold.

flushing is not possible, I live in an apartment complex. I'm going to work on it this weekend and see if i can see anything at the connection of the hose in the manifold. Is there a test to check if the system is working by squeezing the different hoses ?

I realize that 240 is acceptable for stock and all, but the water was steaming out of a hole that recently formed with seemingly no physical trauma. the car has never cycled between 240/190 with the fan on.