changed thermostat, 180,

[ka7gsf]

cant keep coolant in, heater dont work half time. also changed rad cap.

[Kennedy]

We could use a little more detail than that, but it sounds like you are pressurizing the cooling system from the combustion side.

[Onebigcanuck]

If you tape a plastic bottle to the overflow hose, you will be able to see if it's coming from there or through the engine.

;)

[DmaxMaverick]

Welcome to the Forums!

Was this happening before the t-stat replacement? Some models/years do have heat issues right out of the box, and these issues were addressed in later years.

If the heat/heater and coolant puking problem (or some of it) occured after the change, it is very likely you just have air entrapment. This will cause temp swings and poor heater performance. The bleeding procedure must be performed, or the results are very predictible.