This sounds more like the thermostat is jammed closed or the water pump is not working. Your getting a pressure build up if it's throwing water out?. Try pressure testing the cooling system.
CAUTION:Some manufacturers use an aluminum and plastic radiator. Flushing solution must be compatible with aluminum.
Connect flushing gun to water outlet of radiator. Disconnect water inlet hose. To prevent flooding engine, use a hose connected to radiator inlet. Use air in short bursts to prevent damage to radiator. Continue flushing until water runs clear.
To flush engine, remove thermostat. Connect flushing gun to water outlet of radiator. Use air in short bursts to prevent damage to radiator. Continue flushing until water runs clear.
To prevent air from being trapped in engine block, engine should be running when refilling cooling system. After system is full, continue running engine until thermostat is open, then recheck fill level. Do not overfill system.
Warm engine to normal operating temperature. Check compression at cranking speed with throttle wide open and all spark plugs removed. Ensure crankcase is at correct level and oil is correct viscosity. With compression gauge installed, use remote starter to crank engine.
Crank engine 5 revolutions (minimum) and record highest reading. Repeat procedure for all cylinders using approximately same number of revolutions. Lowest compression reading should not be less than 75 percent of highest compression reading. Cylinder compression readings should not be less than 100 psi (7 kg/cm2 ).
COMPRESSION RATIO SPECIFICATIONS
Application. Compression Ratio
Sunday, December 7th, 2008 AT 7:24 PM