This is just my luck. Father in law talked me into getting a blazer and it is becoming a real headache. When I first bought it, it had an upper intake gasket blown and told methat if I could get it cheap- he had the parts to fix it, so I did. Now it has a real issue. Wife drove it to work and the heater stopped blowing out heat- the tempreadabout 250 and she pulled off to the side of the road....
There she discovered an empty radiator- but a completely full reserve- she slowly took off the cap and filled the radiator with warm antifreeze. She heard a gurgle sound and she had heat....but smelled and seemed to have tasted coolant.

When she arrived to work, she still had coolant in the radiator and a full reserve.She then drove it home andshe stated that it looked like she had a big puff of steam (white) come out from under the engine. She bought a new radiator and had it replaced. It worked great for a day or two- then it started back up again. No coolant in the oil,no oil in the coolant, block is not cracked, and we cannot seem to find where the coolant is going!.. She still claims that she tastes coolant every now and then, but she seems to know that if shedoesn't hear the gurgle, she will overheat. Anyone have any suggestions?She has had it checked for leaks too and no leaks of any kind were found. Not even off the exhaust....

 

I have a couple of thoughts.

1) Water pump or a hose is lekaing while driving. There are weep holes in the water pump, and when the truck is off, they typically dont leak. would also explain the coolant taste via the vents.

2) Improperly installed intake manifold gasket. Does your wife notice white smoke out the tailpipe?

 

Ok, Let'sstart out with an attitude adjustment. There are no headaches, just opportunities to achieve satisfaction. With that said, lets start out with the easy stuff...check your heater hoses with the engine hot. Both should be warm/hot. If ones hot and ones not, your heater core is plugged. Try reverse flushing the core BEFORE any attempts are made to replace it. A leaking core will get rid of the coolant BUT you'll smell it heavy in the inside of the vehicle, your windows will fog up and your floorboards/carpet will be wet. Check those places. If the heater core is flowing freely and not leaking, move on to the water pump and connection points to the engine block. The water pump could be going bad (weep hole seepage = bearing failure in your future)or you have a leak from the gasket (s) between the pump and the block. The replacement isn't that hard but I did need to fabricate a tool to get the STUPID fan clutch off..what a PITA. If your changing the water pump, install a new thermostat (165 degree, I believe is stock). Make sure you install it in the correct orientation, I believe there is a tiny bypass vent hole in the tstat that needs to point in the right direction (check a Haynes manual to be sure). If core and water pump check out OK, then you are loosing coolant in the engine block itself or your radiator is leaking. Tell tale signs would be white smoke in the exhaust (burning up coolant and exhausting it) and coolant odor from the tailpipe or leaks under the truck (little puddles maybe). Park the truck over a clean piece of cardboard overnight and check it in the morning. Engine block leaks could be bad gaskets, cracked block, etc...more time and opportunity to achieve satisfaction (you get the drift).. Good Luck.