thermostat opening/closing

[rx7veilside]

am i right in saying that when started from cold there should be no rising level of the water in the filler neck.on start from cold my water temp on apexi matches my post thermostat defi reading..surely the thermo shd be closed so no rising water and no reading on my defi..it should only start rising when the thermostat opens then give a reading to thr defi gge or am i confused

[antnicuk]

there is a small hole in the thermostate but i would have thought the temps would be slightly different.  Is your defi sensor definately in front of the stat?,   also,  its unusual for 2 completely different gauges to read the same temps so you might find there is a difference.

[nikp]

You temp gauge that\'s plumbed in after the thermostat should not be reading anything until it starts to open. Sounds like yours is stuck open.

[rx7veilside]

seems strange yesterday the defi didnt read until thermo opened on the dot at about 82deg yet today it matched the apexi reading almost straight away reading from about 20deg up..am going the chargecooler route soon so rad will be coming out to fit so will change thermo then..reason i was asking is my level in the filler neck settles about an inch above the coolant buzzer which seems quite low

[rx7veilside]

my system seem strange..i have big aftermarket pwr rad as well but ast tank is allways full and overflow tank is full(doesnt overflow) but filler neck level is allways about 2.5 inches or about 1 inch above the coolant level sensor..would have thought ast wld be half full and filler neck wld be full..but these cars are strange..cant seem to find any leaks either

[nikp]

Hmm...dunno about your coolant levels, but as far as the thermostat goes, they don\'t tend to jam open all the time. Sometimes they\'ll work as they\'re meant to, and sometimes they\'ll stick open when they\'re starting to fail. Mine was the same. Just starts to get a bit lazy.