drove my 1995 lt1 to the store today when i got there radiator fluid was overflowing from my overflow tank on way home started running hot then blew apart inline plastic fitting on heater hose any ideas on why

 

Stuck themostat........fan not working............pull the radiator shrould off and get the crap from inbetween cloged heater core

 

fans working

 

Thats one down might as well pull the knock sensors and give it a good flushing

 

Definitely check for dirt and debris in front of the A/C condenser and for stuff between the condenser and radiator. The more stuff that keeps air from flowing thru the radiator, the easier is is for the car to overheat. This is a good place to start; all you need is a garden hose and a nozzle. You may want to try a shop vacuum first to remove leaves, paper, and loose dirt.

As mentioned, a stuck thermostat may be the cause. Even if the drive you took was a short distance, it doesn't take very long for a lack of coolant flow to cause the boil-over. Same with a collapsed radiator hose.

Could be a bad water pump too. But check the easy things first. Replacing an LT1 water pump does take some work and you have to be very careful that any coolant doesn't spill onto the Optispark and ruin it.

With the car back home (and the fitting replaced) and the engine cold, remove the pressure cap and fill the tank. Start the engine and let it idle, keeping an eye on the digital coolant temp display. When the thermostat opens, you will see the coolant start to circulate and probably a quick drop in the coolant level. That will show the thermostat and the water pump is working. Grab the upper an lower radiator hoses to check for heat. Both should feel very warm.

If there is no apparent coolant circulation as the temperature gets to and passes about 160-170, it's probably time for a thermostat.

 

that inline plastic fitting, I believe, is a check valve

 

Actually it is a flow restrictor to limit the flow/pressure to the heater core and surge tank. The fact that it was destroyed makes me wonder if you have engine compression in the cooling system, ie - blown head gasket.

 

What Temperature did the Digital display show, when all of this took place?

 

252

 

hope it is not a head gasket refilled fluids and bleed system and took two short 40 min trips and temp seems to be ok 185-190 average

 

thank you

 

At 15psi water boils at 255, add Coolant 50/50 and now your boiling temperature is 260/265. If the coolant pressure drops suddenly, i.e. a leak, then so does the Boiling temperature of water. At seal level we all know water boils at 212. So it is possible the flow restrictor leak caused a manifested Boiling condition do to a decrease in system pressure. Or, the sudden increase in system pressure was caused by a leaking head gasket.. this happened to me!

Just keep an eye on it, it might be just fine..

 

thank you changed thermostat hoping for the best