Coolant Boiling and no heat.

[Tony91Sport]

I hear my coolant boiling under my hood after I shut it off, plus the car makes like no heat at all. It get somewhat warm when im accellerating, or under a load at a high rpm, then it cools right down when I come to a stop. Do these two things point to a common problem? Could it be my heater core? I changed the thermostat not too long ago, and flushed the system. Anyone got an idea?

 

[unclemeat]

Sounds to me like the thermostat is stuck closed, or the water pump is not working.

 

[Bill Kemp]

Is that a boiling sound or a gurgeling sound? From what you describe I think there is air in the system.

 

[Tony91Sport]

Im not sure if its boiling or not. Its just a bubbling sound I can hear in the overflow tank, so I assumed it was boiling. I thought if the waterpump failed coolant would be leaking out of the weephole, and its not. Is there another kind of failure? As far as the thermostat goes, its fairly new, Id assume it isnt stuck, but if its a last resort ill replace it.

If there was air in the system, wouldnt it have to be alot for me not to be getting heat? I mean, it feels somewhat warm coming out of the vent, but when it hits your face its still cold. When im stopped its cold period.

Thanks for the help guys.

 

[X-1]

Sounds like air in the system, first try this. Before you start it, take the cap off, with the cap off start and let your motor warm up, when the thermostat opens it should pull the coolant down and you will see it flowing thru the fins, this is when you should add more, when it is full put the cap back on, and fill the resevoir to the full line, if still no heat, chances are your core is plugged, mine did that and I had to replace the core.
Good luck

 

[Tony91Sport]

Thanks Exploder. Any tips on replacing the core?