Quick thermostat question?

[AndyTTR]

Just a quick question regarding thermostats; I changed the one in my soarer today and i noticed that the new one (toyota genuine) is slightly different to the original. The disk circled in the pic below is slightly smaller on the new thermostat than the original.



I read somewhere that these type of thermostats were a 2-way valve - when the radiator inlet is closed, it allows the coolant to flow through the bypass. Is that disk the bypass valve? If so, does it matter that its a fair bit smaller than the original? Should I trust the toyota parts guy to have given me the right part?

Cheers,
Andy

[The Real Roadrunner]

how much smaller? 3mm smaller would probly still be ok but the easiest way to check is measure the hole its supposed to cover up. if its 1mm or more bigger it should be fine.

i have an EPC if you want me to check the right P/N, just PM me your chassis details and ill get the P/N for you

cheers
linden

[FASTFOO]

It would not want to be too much smaller as it blocks by pass flow to force the water through the radiator and if it is too much smaller it will continue to by pass and over heat.
This is why if you just remove the thermostat (like in the good old days) it wont run cold it will overheat.
MATT.

P.S. Still got the ST162 ?

[AndyTTR]

Thanks for the replies, much appreciated!

I checked the part number in the EPC, but i think the original isn't made anymore and this thermostat is a substitution.

I searched soarer central for more info and it looks like its the same one that a lot of people on there are using so it must be ok. The car definitely warms up faster now and i'm getting much better fuel economy.

Matt - sadly I wrote the Celica off about 6 months ago, took a tap on the nose that bent the rails and cost too much to repair. Ward offered me $300 for the wreck (even though it had a running gen 3 conversion he would've sold for $4000). I should update the celica thread ey...