Warm up time with new toyota thermostat.

[paulmicin]

My 89 turbo takes at least 10 minutes to warm up. even after i installed a new toyota thermostat. the only mods to the cooling system are a koyo rad and throttle body and idle speed valve coolant bypass. have a brand new water pump and fan clutch also. even at op temp it shows slightly below center on the needle. is it likely that the toyo thermostat is faulty?

 

[jdub]

Is the the big Koyo or OEM size? Did you cut the jiggle valve off the T-stat?

Take it out and test it by heating up a pot of water using a thermometer.

Might be stuck part open...half way up the gauge is a bit high actually. Mine goes to the 4 o'clock position with a CSF radiator and that's in Phoenix.

 

[Clip]

fwiw after my rebuild with a new thermostat (jiggle valve removed) it rests halfway between 3 and 4 on the clock. I have noticed mine takes a while longer to heat up in the mornings in fall/winter now.

 

[Supracentral]

Slightly below 1/2 is the normal position for the stock gauge on a car with a factory stat.

The Koyo is probably the cause of the longer warm up.

If in doubt, remove the stat, put it in a pot of water with a thermometer and start heating it. See when it opens. I do this with all new thermostats to be sure I didn't get a bad one.