where is my coolant going?

[cherokeechief79]

just wanted to update you guys on this.
I pressure tested it and it held fine.running the gage didn't pulse either so that's good.
at 12 psi the vac pod on the heater control valve started dripping a little.
when I tried to add water the coolant level was drastically going up and down and I was getting strange dash gage temps.
once I got enough water in it (took several times)and the overflow tank was full ,everything acted as normal again.the temp gage is constant even at idle at around 185.
my theory is that I had air trapped in the system.
I think I lost water slowly through the heater control valve and when it got low enough the problems arose.
the reason im thinking this is because I have the exact same problem when I tried to change to a higher temp thermostat.
erratic temps and the coolant level drastically going up and down while trying to add coolant.
now im just going to siphon out a gal of coolant from the rad and add straight antifreeze.
ill keep you posted if anything changes but I think im fine now.
thanks for the help

 

[330 uhc]

Reading this thread made me aware that straight water actually carries more heat than coolant, but here near chi town it doesn't matter mostly because of winter...coolant doesnt vaporize ( boil) at higher temps as quickly as water...one advantage...
Back to the main thread...the issue you are having with coolant fill would indicate a remaining problem...any more, if it was me id install a new thermostat...the current batch can't take a joke, and you've been running a gallon low...its probably toasted and sticking...more...it shouldn't make a difference with the higher stat...your engine was built to run a 190°?.. should act the same either way...