My guess is head gasket. the car runs, the pressure builds up, then it forces coolant out of the bad spot. It quit doing this because the coolant was getting low. remove the oil cap, look at the bottom of it. if it looks like it's covered in mud it's a blown head gasket.

 

Check the alternator, it may need replacing. Replace your thermostat, and flush the coolant -- you can get a flush kit at Wal-Mart and other places cheap. Start with those and see where that gets you.

 

Not necessarily, the "mud" could be the result of "Stop-Leak" usage... I would recommend against the use of stop leak in the coolant system -- much better to fix the real problem...

 

Check the GM Service manuals for the exact details about the conditions when the fans come on in stock setup...

Did you flush the coolant yet? How is the fluid's color when you flush it? Look brown & gunky, or fresh? Be sure to use only DEX-COOL...

 

hidy ho the brown or milky color on the oil fill cap would be water in the oil and could indicate a blown head gasket. on the water fill cap it could be stopleak (use for emergency only) or a dirty cooling system.

 

Short of a compression test, i've checked all the signs of head gasket failure and theyre just not evident. Besides, im talking about an external leak, not internal.


I drove her around again last night and she was leaking a small bit. The leak seems very intermittent but its always from the same place. Ive attached photos of where its coming from. Since i took this picture and replaced the water pump and checked all the hoses she hasnt leaked this bad - but she still leaks under pressure and the leaking doesnt start until about half-way on the temp guage.

 

i believe theres a crossover pipe in the back of the heads going from one head to the other. could be that, head gasket can leak externally to. theres a soft plug at the back of the head to. its not leaking inside so that would just about rule out heater core. soo u should be looking at one of those or a heater hose although the heater core could be leaking down the body and coming out there.

 

Thanks for the help guys. I discovered the culprit... a leaking steam vent hose! Right next to the throttle body where the metal pipe is connected to a hose leading to the top of the rad there was a gash on the underbelly of the hose.

Upon removal of the hose, there was a ton of crud at the junction... looked and smelled just like dirt. This kinda concerns me though it was kindof orange. Could just be evaporated dexcool residue or something?