evanh3

I just installed a scangauge II in my tacoma. Coolant temp reads 200 degrees. I have been looking around online and a lot of people have re installed the thermostat and have seen the temp drop. Is it necessary to do that or just personal preference? Will it affect the engine in the long run? Thanks

BigBluePile

iTrader: (3)

What do you mean by "reinstall"?

vital22re

iTrader: (2)

the fsm calls for the jiggle valve to be installed at the 6 o'clock position where most every other motor out there the jiggle valve should be at 12 o'clock.
Depending on where you live and the temps of that area, you may max out the temp gauge faster if you have a mechanical break down. Most likely not then.

ARB1977

Does the six o clock position increase cooling?

rworegon

Can't say that it increases cooling, but there are several observations confirmed with SGII where the temp dropped 7-10 degrees below 200-203 range when moved from the 12 o'clock to the 6 o'clock position using the stock 82C (180F) Toyota thermostat. I run 191F ish in the 6 o'clock position and may hit 193 right before it drops 191 again.

The discussion thread below also has a link to a similar thread on Expedition Portal.

https://www.yotatech.com/forums/f2/5...easure-249481/

OP, it's not that tough to drain some coolant, pull the thermostat body and take a look. If at 12, move to 6 and report your results. Also, be sure your coolant is in good shape and the radiator fins are clean.

BigBluePile

iTrader: (3)

I don't understand how turning the tstat 180* makes a difference. Time to read, eh

evanh3

They say they have seen the temp drop by taking out thermost and turning it so the jiggle valve was at 6 o clock. I was just curious because I am loading up a trailer and moving to South Carolina. I don't want any issues on the way down. I was just wondering if its better for the motor to run cooler than hotter? Obviously overheating is BAD!

Texas_Ace

Yes, it running cooler is good (to a point, you want it at ~170+).

If you are going to open the cooling system anyways, I would take that chance to flush it with some super flush/distilled water and when refilling with coolant use some water wetter. This will generally improve the cooling system on an older truck like this.

rworegon

Normal coolant operating range for the 5vz-fe is 176-203F per the FSM with the 180F t-stat.

BigBluePile

iTrader: (3)

Hmmm....maybe I should turn mine around then.....

rworegon

Maybe you should and, if you have a SG or similar, report the before and after temps.

BigBluePile

iTrader: (3)

I'll have to talk to my mechanic and ask how he installed it

vital22re

iTrader: (2)

It was installed at 6 o'clock you guy!

BigBluePile

iTrader: (3)

He he he

ARB1977

Interesting read. My t stat is original in about 10K I was going to replace it. At some point I'll take readings before and after with my scanner.

ARB1977

Just confirmed my temps with my obd2 reader at 203. I was going to wait till next spring to change out my original tstat but go ahead and change it in a few weeks making sure the jiggle valve is at the 6 o clock position. Would the fan clutch engage less by the engine running 10 degrees cooler?

Texas_Ace

203 is not bad for summer coolant temps. That is what my truck runs at as well during the 100+ degree Texas summers and it never has a problem. The temp gauge never moves from normal.

evanh3

The 180 degree thermostat NAPA sells doesn't even have a jiggle valve. I looked at it today?!

ARB1977

Today I drove for 15 min around my neighborhood and ac on it got to 203 then back down to 201. I also have the two package so I don't know if that made a difference or not. In ten years it never over heated.

ARB1977

Would be interesting to see what the numbers are with this thermostat since it has no jiggle valve.