04 stratus 2.7l v6 .....alright so it overheated on me while driving and when i poped the hood i realized i had leaked my coolant out from the housing thing where the bleeder and temp sensor is at, it was a simple fix and all was good except the temp gauge was a little off, then it stoped working totally, changed the sensor and everything started working perfectly again.

Here's my problem ...i filled it full of coolant again and over a day or 2 checked on it and added if needed blah blah ......temp is good, heating is good, no leaks, coolant level is right, yet after driving 80 miles on the highway i can pop the pressure cap on the coolant tank and not even a drop offers to overflow. the car seems to be running smooth but i have absolutly no pressure there ....not even that hot burst of steam when u turn it half way for the pressure release.

so far all ive heard from people are all sorts of wild theory's of doom that dont make no sense, anyone got a idea of what could be wrong or if its even bad at all since everything seems to be running smooth?

 

The pressure cap raises the boiling coolant point 3 degrees for each for each pound of pressure. When you release a hot cap (never recommended) the boiling point goes to 212 degrees. That is why you get hot overflow. If the engine does not reach a boiling point you get no boil over. Could be you installed an alcohol thermostat the opens at 160 degrees. Your just running too cool.

 

Thanks for the reply man i actually did just change the thermostat in it b4 the snow came, i dont know a whole lot about any of this, i dont know if it was alcohol thermostat it was the standard for $16.99 192 degree with seal, .....my car has always ran pretty cool (no numbers on the gauge) but sits just above the quarter mark.
Is it bad to run too cool? or are u telling me that when it happens for that reason its normal? bcuz its seems to be rolling smooth as ever it just dosent boil over like it used to!

 

The 192 thermostat should be OK. It could be that it is just too cold outside.