No matter what I do, I can't get the damn thing to work. It sucks too because it has to happen when it's cold. A/C still works great. Figures. Anyway, it quit working about the time I dropped in the new engine/tranny. I also have a problem with the temp fluctuating between 145-210 while driving, regardless of speed. Sometimes it fluctuates, sometimes not. So I have a few questions about it...

I had a 180 thermostat before and it worked fine. Now that I have a 160, I can barely feel heat at all. Makes no difference when it's on or off. I have a hard time believing that a 20 degree drop in temperature will cause this. Even when I sit in traffic and it goes up to about 195, it still isn't warm. I know it's winter, but should it cause THAT big of a difference??? For the most part, temp stays around 165-170.

I also re-routed my hoses coming to and from the heater core, thinking that might have been my problem. They go from the outlet on the intake to the LH side of the heater core, then out to the radiator. All of it's new and I have flow through the heater core so I know it's not plugged. Is it possible that this would cause a problem? I bled out all the air as well. I used to have the hoses routed from the intake, through the core, then to the water pump.

This is a Vortec motor but I have the cooling system, except for the heater core, set up the same way as a standard small block. I heard that sometimes you should use the bypass on the front of the intake and route it to the boss on the top of the water pump using a 90* hose. I currently do not have that set up this way since both the intake bypass and the boss on top of the water pump are blocked off. Could that cause a problem?

Anybody have problems with this? I was able to make the heater work a little for a short amount of time before the heater quit working altogether. Any ideas? I'm stumped. Yes, the heater door opens and closes in the dash as well. Thanks in advance! I'm freezing!!!

 

I too am having problems with my heater but my wife drives it more than i do so that adds to the problem. LOL I have changed to stat twice with a 195 * stat and it didnt help at all and I am going to pull the hoses and flush the heater core out today and see what happens but i would like to hear if someone else has had this problem and got it fixed. also the gage dosnt come up to where i think it should so i am thinking that it is with the engine temp. ???

 

how does the blower motor work by itself?

 

the blower motor works fine and the controls feels like it is moving fine on my ta the air will shift from one duct to the other like it is working fine it just wont get to a temp to warm the cabin up to where it is warm and it takes miles to even feel it do that.

 

Mine's the same way. not a whole lot of volume, but the heater is luke warm at best. It used to work great...just hasn't worked to well since I swapped in the 350. I'm also going to flush out my heater core, since the hoses don't feel too warm...

Anybody have any problems with vacuum leaks from the A/C control head in 'htr' or 'def'?

 

I am not sure I read the posting correctly, but are you saying the heater supply no longer is routed to the connection on the water pump? The connections should be coolant coming out from the thermostat housing and going back into the valley pan. That is also the start up minimum flow route for coolant when the thermostat is closed so it should be kept that way. Also 20 deg could make a noticable difference to the heater, because the heat coming out is relative to the temperature difference between the coolant and the air.
However it sounds as if you need to run the hoses from the original places, because the way I read it, you would definately get the fluctuating temperatures.

 

I just swapped the hoses back the way they were...from the water pump, to the heatercore, then from the heatercore to the intake manifold. Ait got luke warm, enugh to get it warm during the day, but not much of anything at night. So I'm going to swap to the 180* thermostat and flush the hoses agin in the opposite direction. We'll see if that works...

Dave Hale
dhale18@cs.com