today after driving for about an hour i pulled into my garage and shut my car off and then i heard boiling coming from the area around the coolant recovery tank. its a 93 z28, i dunno if its normal or if something is wrong. what i did notice is that im mostly running water in the cooling system...can some one help???

 

you need to have a half and half mixture of water and antifreeze in your coolant system. This way your coolant won't boil, unless your car is running at 260F then you have problems. Antifreeze mixed half and half with water will make a liquid that won't freeze when it gets cold out and make so it won't boil when your crusin around on a 90F summer day.

 

yea get a pre-mixed 50/50 solution, didn't you notice your temp gauge going to the red??

 

Maybe the sound isn't boiling. When the engine shuts off, you get a temp spike that expands the water and pushes the excess over into the recovery tank. Also if the purge line from the back of the heads has been inadvertently switched with the overflow tube at the radiator you can get boiling sounds at the reservoir.

 

either way i would say deffinatly get some antifreeze mixed in there with that water.. I'm not sure where your from, but in illinois my radiator or worse my block could crack this time of year if i just filled it with mostly water. Only because it gets colder than a witches tittie wearing a brass braw around here.

 

Sounds like mabe air in the system, or mabe a bad radiator cap, you could also boil your thermostat to verify it's opening fully, and to the right temp.....I'd first double check to make sure the air bleed screw near your thermostat has pure fluid comming out(no air) ....I live in florida and we really don't get much colder than around 30 or so on our coldest mornings in the winter, so I run nothing but 100% distilled water with a small bottle of redline water wetter, or sometimes prestone water pump lube, for their anti-corrosive properties..... my engine temps rarely ever get above 175 to 185.......this never causes any boiling even on the hottest days down here....so I don't know why yours would if all else is alright.......another good benifit is that if you ever blow a head gasket and get coolant in your bottom end, you have much less to worry about , as opposed to having anti-freeze gum all the bearings up........good luck

 

Replace your radiator cap .... very common for that to happen when the cap needs to be replaced. I recommend a new one from the dealer. You won't save much with an autoparts store brand, and it won't be ideal.

Thomas.