FJ60 Engine Temp (T-Stat)

Joined
May 15, 2019
Messages
7
Location
Hartsville, SC
So, I have just finished up a desmog and carb rebuild by @FJ40Jim (Thanks Jim runs very good) and decide to stretch her legs out today. On our trip the truck never got up to operating temps (hour trip). Would this be the t-stat? I just replaced the t-stat and gasket a couple months back along with a new AISIN Fan clutch. I got the t-stat from NAPA and if I remember correctly it was probably the 180F. Could this be my problem? Also, with this being my first cruiser is it normal for the fan clutch to be kicking on at cruising speeds? The old clutch was shot and would never kick on at highway speeds so I am not sure what normal is for a new fan clutch? Or is it kicking on because of my cooling problem? Thanks for any help!
 
Joined
Nov 28, 2015
Messages
1,139
Location
Scottsdale, AZ
The fan clutch is not electrical, meaning if something in the cooling system is no bueno, it won’t default on for safety like on some new cars. With that being said, if you can hear the fan clutch, the engine is reaching a high enough temp to engage it. I would make sure via an aftermarket gauge and/or an IR temp gun what temp the truck is actually seeing. Also make sure the coolant temp sensor has a good connection. The factory gauge is notoriously incorrect.
 

OSS

Joined
Jun 30, 2017
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Oblivion
Remove the top thermostat housing and inspect the thermostat. Make sure its not upside down or jammed open and that there's the correct rubber gasket on top of the t-stat sealing it to the bottom of the housing.
The 190° thermostat is a better choice.

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Joined
Apr 23, 2005
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2,959
Location
Oregon
I agree with OSS. Make sure you have the top gasket (#16346). Without this gasket, the motor won't get up to operating temp.
 
Joined
Dec 19, 2007
Messages
444
Location
Harrisonburg, VA
As said above, check the installation 1st, sounds like that is your problem. I ran a 180 before and the operating temps weren't high enough.
 

klinetime574

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Jul 23, 2006
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5,524
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Chicagoland, IL
That o-ring looks okay to me. It’s new with the thermostat correct?

Just to clarify “never got up to operational temp,” what are you referencing here? Halfway on the gauge, I’m guessing. With a good fan clutch it’s gonna read lower. Check your heater next time you’re cruising on the freeway. If it’s hot then you know your coolant is at the correct temp.

HTH
 
Joined
May 15, 2019
Messages
7
Location
Hartsville, SC
@klinetime574 yes both were bought new. Well yesterday it never got halfway on the gauge and as i stated above the fan clutch was coming on cruising down the road at 45mph? I just put the t-stat in water and it opened at 188F. I just order a new O-Ring and housing gasket from Toyota. Not sure what else to do i might just be overthinking it.

Sitting in the driveway idling the heat was hot. Also I think am going to order a mechanical temp gauge.
 

micruz60

Unleaded Regular
 
Joined
Nov 6, 2006
Messages
2,815
Location
just out of the J-Hole
I have had better luck using a fiber type top gasket, over the years, that rubber degrades. I have found arcs of it floating in the radiator neck.

Do you get good heat in the cabin regardless of the 'cool' running?
 

FJ40Jim

The Cruiser Whisperer
 
 
Joined
Sep 26, 2003
Messages
10,662
Location
Lancaster, Ohio, USA
FWIW, The fan clutch is engaged by hot air and radiated heat from the radiator warming the coil on the very front of the clutch.

The clutch can't see the coolant temp in the engine or water pump.
 

g-man

SILVER Star
 
Joined
Sep 5, 2006
Messages
2,349
Location
Charlottesville VA
Normal op temps should read between 1/3 and a little under 1/2 on the gauge. You can put the t'stat in boiling water to check if it opens and closes.
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Make sure your sender wire is good and you have tight contact on the temp sender. If that checks out you can resistance test the sender:
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