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Coolant temp normal operating range

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Coolant temp normal operating range

Postby magicdeo » Fri Oct 16, 2020 8:23 am

Gday. Has anyone got a digital coolant temp gauge on a 4jb1t? I’ve had one fitted to my Ute for a few years now and I want to know what a normal operating temp would be. My Ute always sat just under halfway no matter what (when the standard sender was fitted) but with the new gauge, on a hot summers day working hard I can reach 105 degrees C. Ive checked/replaced everything I can think of over the last few years and the cooling system seems to be in good condition, maybe this sort of temperature is normal? The coolant never boils and it never seems to be an issue to the engine, I just want to get it sorted if it’s running too hot.

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Re: Coolant temp normal operating range

Postby geeves » Fri Oct 16, 2020 9:44 am

15 pound cap means boiling point is 121C. 105 is no issue
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Re: Coolant temp normal operating range

Postby isuzurob » Fri Oct 16, 2020 5:28 pm

All mine have run at around 65 degrees Celsius crusing at 100km giving it all it had max temps were 94 I ever saw on a 30plus day
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Re: Coolant temp normal operating range

Postby magicdeo » Sat Oct 17, 2020 6:53 am

Mine will never sit below about 83 even on a frosty morning which is no issue for me at all due to having an 82 degree thermostat. But going over 94 doesn’t take much work.
Geeves, although the boiling point is above this, how do I know that the engine will still handle those temps without issues?

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Re: Coolant temp normal operating range

Postby geeves » Sun Oct 18, 2020 6:16 am

In theory they set the boiling point as a safety valve to prevent damage. The engine boils before it implodes. Theory is good anyway. I had my old 2.8 off scale without boiling when I wired an electric fan into the charging circuit then killed an alternator before a 400 meter walking pace climb no damage done. (I drove it for another 4 years) I had my wizard off scale for a short time when the fan pulley split throwing the belt. I sold that within a year but no obvious harm.
Certainly running near boiling is not a good idea and if normal running is getting you close you should be looking for the reason.
Fan requiring new viscous oil
Fins blocked with mud
core blocked with rust
waterpump corroded
timing out
injector issues
turbo issues
auto trans issues
aircon radiator blocked with mud
are all common
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