Coolant system on 2001 Nissan Sentra

I have no heat in the car until I drive at hyw speed then there is lots. Car does not overheat and I flushed the heater core out with a garden hose and it was clean. Thermostat is new and the rad has also been flushed. If the pump fails, would it not overheat the engine? Thank you

by in Albany, NY on January 27, 2011
1 answer 1 comment
ANSWER by on January 27, 2011
Not in the winter time in Albany, I have been there and, wow, it gets really, really cold. If the impeller of the water pump gets worn out, the engine has to spin much faster. And, check to make SURE that your radiator flows very nicely, that too will impede the proper circulation of the coolant. I know that you flushed it, but HOW does it flow? And, don't forget to check any of the heater control valves, to make sure they are letting the coolant flow properly.
COMMENT by on January 28, 2011
Where are the heater control valves? Are they vacuum opperated? I seam to be getting a lot of air bubbles coming out of the bleeder, is this common or due I have a bad head gasket? Today it was running hot then cool down to normal, then heat up again and I had no heat at all in the cabin. grrrrrr Thanks for your help
Related Items:
my heat only blows when the car is moving and when i'm at a red light it starts blowing cold air as soon as i start going again it gets hot,the faster i go the hotter it gets.i'v put a new thermast...
Computer Continues to say that there are multiple misfires in the cyclinders. Could this mean they all need replaced even though the dealers I've taken it to says they are not sure whats going on.-...
Car continues to overheat and coolant leaks out fairly fast.
guage on dashboard shows engine running hot, it'll then go back to normal, then hot, a continous cycle. I have changed the thermastat but the problem still exists. What am I missing or what do I ...