I havea 1997 Blazer 4X4. I have a couple of problems but maybe they are related. When driving around I hear sloshing noise coming from behind the dash board. Its like there is a stream back there. I also have a problem with the amount of heat coming out. When you put on the heat it will blow out heat, not very hot and not very much pressure. IfI move the temperature from hot to cold the pressure picks up dramatically. Does anyone have any suggestions on either of these problems.

 

clogged heater core... orrrrrr... in one Monte carlo SS i had a bunch of leaves got caught in the venting behind teh blower motor trapping rain water, i suggest you remove the blower motor and stick your hand in the hole and see if there are wet leaves and water puddeling back ther, if not that pull the hoses off yoru heater core and flush it out with a garden hose. thats what I would do

 

I'd say the same about the core. Flushing is quite easy. Run a search and you'll find the answers you seek.

 

Yea my blazer too seems like it has a stream of water behind the dash only thing is that I get a good amount of heat and cool air.

 

I'll third that about the water sound. It seems like it's only on acceleration from a stop though. My heat is 'f'ed but the pressure is just fine, I have another post about the heat. https://blazerforum.com/m_59570/tm.htm

 

William,

Does it sound like a gurgling noise? Mine had a similar sound and it turned out to be just a bad radiator cap. Try that first and see before you make any expensive repairs.

Tim