i just picked up a 98 4dr blazer a few weeks back and i belive shes leaking some coolant. i did some searching on the forums and didnt find any common causes. i noticed a smell of coolant first, then saw some on the driveway, then checked and sure enough there was coolant on the underside of the engine. it seemed to be forming a drip off of the transmission...


also, a side note... when i accelerate with the heat on i can hear the coolant running into the cabin of the truck through the heater core... is that normal?

 

check your oil. Does it look milky? When my intake manifold gasket decided to go...it would leak very little..but it was out of the back of the engine so it sorta looked like the tranny. It would put most of the antifreeze in the oil. So just a thing to check...I dont think think thatll be the deal for you...lets hope not.

 

Check the passenger floor boards and transmission hump if the carpet is wet then the heater core took a dump on you...

 

oil is not milky, and the pass. floor is not wet, nor can i smell any coolant in the cabin of the truck...

im thinking it may be a transmission cooler line. whether it be the seal on this line or what i dont know, but there are 2 aluminum coolant lines that run into the transmission (one in one out im assuming) and that seems to be where the leak is coming from...

 

Did you check the tranny fluid for contamination?

If the coolant leak is at the connector then you will need to replace the radiator. It has plastic side tanks and any leaks are fatal. These tanks are only rated for 16psi caps so they are not repairable effectively....not like the old metal radiator tanks.

 

You just have to clean it off,and watch it to see where it's coming from. Pain in the butt, but I can't think of another way.