Help me solve my coolant/heater issue...

[teamgs]

Greetings,
The past few months, I have noticed that I have no heat. The blower still works, just no hot air. My car has 200K miles on it, and I have replaced the heater core at around 130K, if I remember correctly. There is no tell tale smell of coolant, nor the leaking on the carpet, nor the dramatic loss of coolant, so I don't think the core is bad. I tested the core for water flow and it isn't obstructed.
What is really odd, is that today I returned home from work, determined to pull the dash and see if a diverter or something is disconnected from the temp dial, and as I got out of my car. I could see the coolant just blowing out of the overflow container and overflow cap. Really steaming and under pressure.
I recently, changed the coolant, and am sure that I have a coil in the lower hose. The water pump and thermostat have been replaced, though somewhere around 110K miles.

Any ideas as to either of the two problems? Does anyone think they may be related?

Regards,

Gary

 

[mo_dingo]

If the system does not leak until the car overheats, then you have a lack of water flow. So, your water pump is bad, or your thermostat is bad. The thermo is cheap, and easy to replace. Try it, and see what happens.

Here is another test. Are you getting pressure on the lower radiator hose? When the car reaches normal operating temperature, are both hoses hot? If not, this may be a sign of the thermostat sticking.
Scott

 

[teamgs]

Hey Scott,
Even though though the thermo has been replaced, I was thinking about it as a culprit. I have occasionally noticed the temp gauge jump around from no temp to mid range then back down again. A sticking thermo could also be blocking water flow to the heater core as well, correct?


Regards,

Gary