first one is i just replaced my thermostat but now after i replaced my thermostat i filled my radiator full of coolant and my recovery bottle to the max line by five days after i did all of that i had to add a gallon of coolant to the radiator is there some where it can be going and it isn't leaking. my second problem is my heater control won't change where the heat is going to it is stuck on the vents is there something i should be looking for or replacing.

1998 chev blazer ZR2 with a k&n intake and a poweraid throttle body spacer on it

 

For the coolant leak I would check the oil, make sure the oil looks good and not milky. Then look around the edges of the intake, they like to leak there. If all this is okay, you could have had an air bubble that took a little to get out of the system. But I would do a pressure test just to make sure. Now for the heater control, where the PCV valve hose attaches to the intake there is also a smaller vacuum line that attaches there as well. Make sure that line is still attached and in good shape.Then look at the black ball attached to the hood just above the brake master cylinder, and make sure that the vacuum line that attaches to that is still there.It likes to fall off the ball. Also check the vacuum lines between the intake and the ball to make sure all of them are good and still attached. If all these check out I would think that either you have a vacuum line under the dash that is bad or possible that the heater selector switch is bad, or you have a problem with the actuators on the heater case themself. The default is supposed to make the air come out of the defrost vents, but I have seen so many where they stick in the vent position. HTH, Korey.

 

When you filled your radiator did you do it with the engine running?

 

Does the engine idle rough?? then when you increase throttle does the engine smooth out?? This is the first indicator of a vacuum leak.

As Kordog said check all the vacuum lines to and from the vacuum source, there isa TSB about the switch on the drivers side transfer case failing. It will doa fewthings loose vacuum which are cause the engine to idle rough, loose HVAC controls and with the seal in the switch failed it allows fluid from the transfer case to be ingested into the vacuum system which will also cause the HVAC switches and lines to fail...

 

Does your hood bulge too? I got the same setup. But w/ a Granatelli MAF.

 

this has nothing to do with it but you might want to take off the TB spacer. For the 4.3 it doesn't do anything at all even with the intake. I ended up wasting 90 dollars on mine.
In some cases, it actually reduces power.

 

i just changed my t-stat sunday and filled it up. i put about a gallon of coolant in it in over 3 days. i know i was leaking where the hose connects to the t-stat housing. i had put the hose clamp below the projection and had to raise it up above it. are you sure you're not leaking? could you be leaking and its burning off before you notice? you might want to check the where the hose connects on either end if the setup is anything like mine. also is the drain plug fully closed?
good luck

 

Is the cab getting heat? Does the water temp rise?
Good question.

Hope the coolant isn't filling the tranny. Check the tranny dipstick for unusual colors/ oil consistancy.

After a while I felt the TB spacer was a waste too. Such as when I got my credit card bill after purchasing all those BS bolt ons.

 

yes my hood does bulge and it wore off the hood liner in one spot

but i have checked all of my vaccum hoses and they seem fine i don't know what to do next

 

Why does your hood buldge?[:-]