okay maybe i'm not understanding how a thermostat work but how does a bad thermostat keep you from having heat in the car... someone explain.. i thought the waterpump circulate coolant into the block.. from block to lower hose and into rad.. rad cools it off and it enters the upper hose into thermostat and all over again.. i don't know

 

Yes, a stuck OPEN stat can casue the car to not get up to operating temp. This is not got on the engine or MPG.

 

The heater circuit loop circulates all the time (depending on where the temp control valve is set if that's how it's regulated). A stuck closed thermostat will not open to allow coolant to flow through the radiator and cool off and may cause overheating of the engine.. A stuck open thermostat will cause the coolant to be cooled all the time and the engine won't get up to operating temperature or provide enough heat for the heater core.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by soon2bdropped &raquo;</TD></TR><TR><TD CLASS="quote">... someone explain...</TD></TR></TABLE>The waterpump circulates coolant ALL THE TIME through the engine block & head, thru the heater core, and thru all those little hoses to the TB, etc.

The thermostat is located in the suction tube to the pump. If the temperature there is too high, the thermostat will draw some coolant from the lower (cold) radiator hose & let it into the pump. This mixes with the hot coolant coming from the engine to provide the proper temperature.

If the thermostat is stuck 'open', then it's taking way too much cold coolant from the radiator, which over-cools the entire engine. Then your heater core never gets very hot.

 

dont mean to thread jack but i didn't wanna have to open up a new thread and get flamed to SEARCH, but if my rad cap remains cold all the time, and the heater like is hot one minute and cold a little bit later, then gets hot again is this a bad thermostat? Also after a while of driving i noticed that antifreeze was leaking and the temp went high, and when putting the heater on full blast the temp gauge would slowly go down and there wouldn't be as much leakage. I don't know there the leaks coming from either, but it seems as if my rad cap is like melted and not air tight anymore so it could be spraying from there. Please let me know what you guys think my problem is.

 

I'd say just replace the thermostat and cap and be done with it. Those two items won't be that spendy and are really easy to install. Just make sure you bleed the coolant system afterwards, as you may get some air bubbles in there when doing the thermostat.

 

Rad. caps and Thermostats are so cheap that when in doubt just replace!! You are damaging your engine by running it that way. Flush and refill the collant while you are at it.