Changed my thermostat and flushed my radiator, and replaced the top radiator hose. Still no heat and now my Temp gauge runs how when on the freeway but stays middle while residential driving is my water pump dying?

 

squeeze the top hose and feel if it's pumping, be sure you've got enough coolant in there, thermostat isn't backwards. maybe your belt just isn't spinning the pump?? hopefully the heater core isn't blocked.

 

If the heater core is blocked do I have to replace it?

 

probably, you gotta take your whole dash apart to do it too. i've never done it, but quite a few here have.

 

whenever you do ANYTHING with the coolant on these cars you need to bleed the system.
You probably just have airpockets running in the system,

 

I got the impression that this same problem was his original reason for replacing the tstat..

 

Yes my whole reason for changing the thermostat was to hopefully regain heat again. I wasn't sure why the heat went out in the first place but with the weather being so crazy I just didnt want to be without it.

 

if the engine wasn't over-heating and you had little or no heat, i doubt if the thermostat was at fault. air pockets in the engine are a design "feature" of our engines that cause no heat. 2 other possible causes are a plugged heater core and the water control valve for the heater core.

right now you may have the thermostat in wrong, but you probably have air in the engine. there is a bleeder screw (bolt) on the top of the engine by the firewall that is supposed to let all the air out. some people have said it works, others say it didn't work for them. before nissan added the bleeder screw, the proceedure was to jack up the front of the car until the bumper is 39 inches off the ground and run the engine for 15 minutes or so with the radiator cap off until all the bubbles are out. this still is a valid proceedure.

 

Can you use your normal car jack for this?

Also, I've bled mine while the car was sitting on a pretty steep slope, will this work as well? (it didn't really work for me, but I don't know if there's another problem or not other than air pockets).

 

does your normal jack go up 3ft?
I managed to bleed my VE on level ground