my 82 trans am has started leaking only when the ebgine is cool. 305 code H engine. it will pour out from the bottom but I can't tell exactly if it's from the top pouring down to the bottom. I can't see it. just it dripping all over the ground. it puts out a big puddle. it does this while the hose is cool until the ther. stat. opens. when it's warm it stops leaking. I can drive it for the rest of the time and no drip at all. any clues?

 

I watched it today to see when it happens. it doesn't drip at fisrt. after about 5 minutes the engine is at around 190 degrees when it starts. the hose from the water pump to the radiator startsa getting hot and the nthe drip starts until it starts pouring. the upper radiator hose is still cold. around 200 degrees or 220 the therm. stat. opens and the upper hose gets hot. when this happens the pouring stops and it never leaks for the rest of the time until the next day when it starts warming up again. ???

 

First two things that come to mind, try giving the hose that it is leaking from a few pinches to see if the hose is cracked or flaking, also make sure the metal clamp is tight enough around the hose.

-Russ

 

definately sounds like a cracked hose. More like a slight crack. When it's cool the crack is there and leaks when coolant runs through it. When the hose gets hot the hose expands enough so that the crack kinda seals.

That's my theory though . I'd just check all the hoses for cracks.

 

I checked again and it is not the hose. it's coming from the radiator somewhere but I can't see it b/c of the fan and bracing. it comes directly from the bottom around the middle.

 

take the fan off and give it a good checkup. To remove the fan, atleast on mine, it was only 4 bolts that go through the radiator support and 2 more down near the tie rods. Also 1 clip for power, then it lifts right out. You should be able to have some good clearance to give a good look at it.
If you cant find it while its in the car, take the radiator out and plug the holes and fill it with water and give it a shake. The radiator is only held in by 2 bolts and the two tranny cooler tubes(if automatic)

-Russ

 

If it leaks when cold & stops when hot.Probably the alum or maybe even the plastic tank is cracked.When it gets hot the aluminum expands & seals the crack.When it cools the alum shrinks & the crack opens up again,same thing applys for the plastic tanks...If its not leaking in the begining perhaps its because there is not enough pressure in the system to force the fluid out(it may just be a microscopic crack "pinhole").As the pressure builds it starts to force the fluid out the pinhole.When the temp reaches 220 & the stat opens.It equalizes the pressure & along with the higher temp the leak stops because the 220* heat forces the material to expand, closing off the flow.Thats my theory anyway, id check the rad.