Radiator hose bulging and coolant coming out of drain on bottom of radiator?

[91civichatch2571]

My upper radiator hose is bulging where it meets the block. Also, theres a drain type thing on the bottom of the radiator and coolant is coming out of it. Another thing thats wierd about all this is that the reservoir is filling up with coolant. Is there a clog somewhere or some shit? whats going on? This thing never ever runs right...

[BullShifter]

t/stat stuck closed - repalce

[91civichatch2571]

would my heat work alright if my thermostat were stuck closed because it still does work fine.

[91civichatch2571]

Another question, can I use a thermostat from a ZC to replace the Si's? Im sitting here holding them side by side and they do have their differences. But will they both open at the same temp and whatnot?

[Setanta]

Lots of work here as it looks like your hoses are dead too.

#1 Replace the thermostat
#2 Replace top and bottom radiator hoses (bulging = lack of rigidity = weak = prolly split soon, if one is going, you can be sure the other will too soon). Replace all clamps with new ones.
#3 Replace the bung at the bottom of the radiator and it's washer with brand new ones (radiator specialist should have one)

#4 New radiator cap. The reason water is going into the ancillery bottle is because the cap is not applying the pressure to reduce boiling point, nor is it sealing the overflow point. So replace it.

Optional: Replace heater hoses as they will be on their way out too and the pressure will look for the weakest point in your system. I'd think of doing any of the other cooling hoses too - there are small ones on the setup here and there. Same reason.

After having done these steps, get a professional reverse flush done to remove scale etc and fill with coolant mix, not water (this will protect the hoses in future).

BTW - thermostats jam half-open or fully open - rarely closed, you may have sscale or something clogging your heater core, it could even be at the stop-cock on the heater.

To ID the thermostat, look at the small number stamped on it - it should be similar. Don't forget a real gasket for it - don't reuse the old one.

Cheers