temp going up. no heat coming out?

Question

1992 Cavalier. Just put new heater core in. worked fine for first few days, not I notce coolant light on, heat gauge goes up pretty fast with NO heat from heater. Upper radiation hose not even warm. Could be caused by low coolant, kinked hose down by heater core nipples. (they were not in the greatest shape anyway). Loose hose clamp, or could be shot down thermostat. I heard that anytime a vehicle overheats you should have the thermostate replaced just for the sake of it. Correct? Drip does not appear to be coming from heater core, no fog when defrosters turned on, so thats good I guess. Thanks

Answer 1

It sounds like you don't have any coolent circulating in the system as the upper hose is not hot and there is no heat coming out.

Check your coolant level. Is it low?

Check the hose coming out of the water pump. Is it firm like it is full of coolant, or is it soft like there is nothing in it? You may have to remove the hose from the top and pour coolant down it to prime the water pump.

Check the hoses. Any splits or kinks that might keep liquid from passing?

Any leaks in the area you just did work?

Replace the thermostat. They can go bad, but I've never had it happen. Try this first as they are cheap and easy to replace

Replace the water pump. It could be that the pump just went bad.

This should get you started.

Answer 2

First thing is to check is water level in radiator, -do this when engine is cold,-(otherwise you are subject to getting scalded by the hot water). The thermostat isn't a lot of use to you unless there is water there to make it hot enough to operate, so I would check to see if water is indeed in the system. I would think that the coolant light is "screaming' to you that you need water, (as that is what it is there for!) If it still overheats when the system if full of water, ----then replace the thermostat!

As for kinks in the hose, you should be able to see that when you look in that area. And of course a loose hose clamp allows an "exit" for water! Driving the car with insufficient water can cost you an engine, or at least a "head" replacement, or rebuild, so don't continue driving the car till you find out what is wrong!

Answer 3

i own a repair shop,and yes you should replace the thermostat pretty often,but what might have happened to it,,,it migh not have gotten all the way full the first time,this will cause it to heat up a little,id re-check the coolant on it and make sure it is full,also check to see that its circulating real good through the engine,open up the heater to full heat and turn the fan on high speed and idle the car up a little it may start circulating real good ,if not it may have a water pump on on it that doesn't want to move the coolant very well,this is caused by the fins on the water pump getting worn out on it,if all else fails ,check the water pump,it may be getting worn out on it,good luck i hope this help,s.

Answer 4

Low coolant level.
Master tech 40 yrs.