[Morphyne]

I am trying to flush my cooling system and I let this thing run for 30 minutes or more. Coolant temp go to 185. When I go to drain the water coming out is cold. Thoughts on this?

[L8Shift]

Originally Posted by Morphyne

I am trying to flush my cooling system and I let this thing run for 30 minutes or more. Coolant temp go to 185. When I go to drain the water coming out is cold. Thoughts on this?

I just installed a 180F Stat.

If the engine temp does not go over 200, I would think all was ok.

My engine would reach 210F, still needing to be burped.
(Sitting in the driveway)

If the stat was stuck closed (and you were not in a frozen climate), temps would rise rather quickly after it warmed up..

mi .02

[azgold]

You can remove the T-stat, and test it in a pot of water with a thermometer per the FSM. Always purchase a OEM thermostat from the dealer.

[rdruss]

Doesn't matter if stat opens or not, you are draining from bottom of rad so with cap off you will drain rad and part of engine, that part of coolant that comes back from water inlet ( at water pump I assume), there will still be some coolant in the block/heads, will have to try and get that from plug(s) on side of block.
I wouldn't worry with the small amount left in engine, drain rad and overflow bottle, refill and top off overflow for next couple days and you're good.

[AuSeeker]

Originally Posted by rdruss

Doesn't matter if stat opens or not, you are draining from bottom of rad so with cap off you will drain rad and part of engine, that part of coolant that comes back from water inlet ( at water pump I assume), there will still be some coolant in the block/heads, will have to try and get that from plug(s) on side of block.
I wouldn't worry with the small amount left in engine, drain rad and overflow bottle, refill and top off overflow for next couple days and you're good.

I don't think his concern about the thermostat not being opened was because all the old coolant may not drain out, It seems he's concerned that the thermostat isn't opening properly when it's running because when he did drain it after warming up the engine the coolant wasn't warm but instead cool/cold coolant was what was draining out.

[rdruss]

If your stat not opening you should be running hot when driving, How did gauge look last time you drove it?

[Morphyne]

So apparently the t-stat is working just fine. Return hose gets hot and when I I drain the liquid it is still tinged pink so its mixing with what's left in the engine. I just thought the drained liquid would be hot enough to burn me. But its coming out at about 100 degrees F.

[firebirdguy]

Originally Posted by Morphyne

So apparently the t-stat is working just fine. Return hose gets hot and when I I drain the liquid it is still tinged pink so its mixing with what's left in the engine. I just thought the drained liquid would be hot enough to burn me. But its coming out at about 100 degrees F.

how/where are you measuring the 185 & 100 temps?

i replaced my radiator a few months ago filled with new coolant, now when i check the rad tanks & hoses & thermostat neck with a infra-red temp gauge, the hottest it shows anywhere is about 160-165, even in 90+ temps & letting it run with a/c on for 1 hour it will not get up to the rated t-stat temps.

so either my original t-stat is stuck open & the rest of the cooling system is so good on these 4runners that it wont let it get to full operating temp, or my gauge is bad, but it checks withing +/- 3* when i check it on other things. i plan to change the t-stat this spring, & get a scanner to connect to the OBD port to see what the temp sensor is actually reading.

[Morphyne]

185 I use obd 2 sensor bluetooth sensor and torque app
100 I used my hand

[BackOff]

I had the T-stat out and just water and could ony get up to 135*f.
...just for info.