FJ60 water temp gauge spiked / heater blows cold (1 Viewer)

[Landcruiser Nut]

I know you said you have checked the temp gauge for function, but I still suggest buying a $30 IR temp gun to verify that you actually have an issue.

IR guns are very useful for future projects also. You can’t go wrong by buying one.

Thank you
Yes I used an IR temp gauge on the hoses, the water pump and radiator
Various readings ranging from 150 to 185
Thank you
Keep the ideas coming please

 

[Landcruiser Nut]

My experience with the 2F in the FJ60 is that it can take up to TWO WEEKS of daily driving to purge all the air that enters the cooling system when it’s opened up.
Until then - gauge reads hot

Thank you
I’ll drive it more and see

 

[Landcruiser Nut]

Before the dynamite, install another coolant temperature gauge and sender not made by Toyota.
Maybe the engine isn’t running hot and it’s the 36 year old flakey gauge that’s going haywire.

I replaced it with a different gauge and it said the same I’m going to try another sender and combinations of all of them
Thank you
I think it’s something simple but I just can’t figure it out

 

[Landcruiser Nut]

This may be a dumb question but can you remove the sending unit while it’s running and burp it that way

 

[John McVicker]

@LandCruiserNut if your IR temps are 150-185 as you say, it would seem to say you have a faulty gauge and no cooling issue.

 

[Landcruiser Nut]

And thank you all for trying to help is very much appreciated

 

[Landcruiser Nut]

@LandCruiserNut if your IR temps are 150-185 as you say, it would seem to say you have a faulty gauge and no cooling issue.

That was my thought too that’s why I replaced it but it ended up being the same
I even grounded the wire from the sending unit and it pegged it out,
It takes it a while for it to go full hot but it doesn’t peg completely out when it’s running

 

[John McVicker]

Did you replace the sending unit with a OEM or aftermarket?

 

[Landcruiser Nut]

Did you replace the sending unit with a OEM or aftermarket?

OEM

 

[OSS]

Don’t unscrew the temperature sender when the engine is hot. Cooling system is pressurized at 14psi (when radiator cap is on) and blazing hot.

The engine will eventually purge out all bubbles on its own without any intervention. It just takes a long time.

 

[g-man]

Thank you
Yes I used an IR temp gauge on the hoses, the water pump and radiator
Various readings ranging from 150 to 185
Thank you
Keep the ideas coming please

so this means the engine is NOT over heating but rather you have a high reading on the gauge. When you say you replaced the gauge, did you replace the 4 gauge cluster? Or just the temp gauge? I recall the temp gauge is grounded through the fuel gauge. A worn out filament in the fuel gauge can affect the temp gauge. but I forget which way it does this.

Since you replaced your sender with a new OEM unit that is most likely NOT the issue but you can ohm test the sender to see if it is within specs.

You can also test the gauge:

 

[Gretsch]

My experience with the 2F in the FJ60 is that it can take up to TWO WEEKS of daily driving to purge all the air that enters the cooling system when it’s opened up.
Until then - gauge reads hot

The engine will eventually purge out all bubbles on its own without any intervention. It just takes a long time.

This has always been my experience as well with doing anything to the cooling system. Takes weeks of daily driving and burping sessions to get things back in order. You can burp and burp and still it runs hotter than normal until whatever air or voo doo works its way out of the cooling system. Seen it on mine many many times. OP since you have confirmed with an IR gun the temps are in a normal sort of range, you prolly just want to verify the gauge cluster idea above and move on.

System is pressure tested with engine off to test for leaks? Heater temps hot? I didn't see that mentioned. Maybe I missed it.

 

[Landcruiser Nut]

This has always been my experience as well with doing anything to the cooling system. Takes weeks of daily driving and burping sessions to get things back in order. You can burp and burp and still it runs hotter than normal until whatever air or voo doo works its way out of the cooling system. Seen it on mine many many times. OP since you have confirmed with an IR gun the temps are in a normal sort of range, you prolly just want to verify the gauge cluster idea above and move on.

System is pressure tested with engine off to test for leaks? Heater temps hot? I didn't see that mentioned. Maybe I missed it.

Thank you all
I’ll test the guage with a voltmeter
And run it and see if it works itself out

 

[Gretsch]

Fresh OEM sender shipment from @ToyotaMatt:

What did you do with your 60 this weekend?

Catching a snake in the road (Florida pine snake and somewhat rare) and picking up roadkill. In this case a young river otter in great condition. Snake was released and river otter will live on as a taxidermied specimen.

forum.ih8mud.com

 

[Landcruiser Nut]

Don’t unscrew the temperature sender when the engine is hot. Cooling system is pressurized at 14psi (when radiator cap is on) and blazing hot.

The engine will eventually purge out all bubbles on its own without any intervention. It just takes a long time.

Thank you
I should of clarified as I was burping
But thank you for letting me know it is under pressure.
I’ll avoid that route