Same situation here as FJ1969 my '78 never gets more than half. Typically between 1/3 and 1/2 no more. Burp out air....
Hot or Not? (1 Viewer)
- Thread starter FJ4013
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That block seems awful hot to me. Tomorrow I will drive mine and ensure it is hot, (and it will be), and take the same IR temps as you. Basically , 195 to 220 is what the range is for a block but yours seems to be on the high side and even over. Perhaps the water pump is not pumping well. Also could be crudded up block. If the coolant is good pressure, and the coolant is free to circulate the block without obstruction, I believe 195-200 would be normal.
Top of your rad tank was 195f? That does seem hot. The list of suspects not that long. Thermostat/ h2o pump/belts tite/fan clutch(if have). Have you made changes to engine? Getting any "ping". Also reduced air flow is worth checking, but I'm sure you did that obvious stuff. There is a good thread on fan clutches
as others have suggested... burp the air out of the cooling system, before you change anything.
Air in the cooling system makes the engine run hot.
Common after a flush.
There are many links with instructions... this link contains videos
Air in the cooling system makes the engine run hot.
Common after a flush.
There are many links with instructions... this link contains videos
- Thread starter
- #26
Is there a bleeder valve on the FJ thermostat? I've watched a few videos on how to bleed air and they all reference loosening the bleeder valve when adding coolant at the first step.
If the temperature reading on your dash is always at the same level with high and low ambient temperature, the thermostat is regulating it. If you want to compare temperatures with others make sure you have the same spot while measuring and try to calibrate the different devices. Like measuring in an open pan with a similar layer of water that is just kept to a boil.
To ease your mind I would just take the thermostat out close it and flush the block through the radiator hoses. Replace your thermostat and run it. You can also run it without the thermostat, temps should be lower.
To ease your mind I would just take the thermostat out close it and flush the block through the radiator hoses. Replace your thermostat and run it. You can also run it without the thermostat, temps should be lower.
When the heater is turned on does it make the temp readings drop?
If not it is not running hot in a way that there is something wrong.
An engine running hot means the coolant is boiling and air pockets prevent the heat from being tranfered out of the block to the radiator.
An engine can run warmer but is restricted to the maximum temperature the coolant can handle before it boils.
Coolant boils at a slightly higher temperature than water and when under pressure the boiling temp goes up. This is why you do not take the cap of a hot radiator, pressure drops and coolant instantly boils.
Having a higher temperature is not a problem as long as there are no real air pockets in the system and temperature is steady. It does minimise your safety margin if something happens.
I hope this will help you.
If not it is not running hot in a way that there is something wrong.
An engine running hot means the coolant is boiling and air pockets prevent the heat from being tranfered out of the block to the radiator.
An engine can run warmer but is restricted to the maximum temperature the coolant can handle before it boils.
Coolant boils at a slightly higher temperature than water and when under pressure the boiling temp goes up. This is why you do not take the cap of a hot radiator, pressure drops and coolant instantly boils.
Having a higher temperature is not a problem as long as there are no real air pockets in the system and temperature is steady. It does minimise your safety margin if something happens.
I hope this will help you.
No bleeder valve...
But, some people drill a small hole in the thermostat flange, to allow air to 'bleed' past, as a way of eliminating the need for burping.
How would you do that? I'm assuming remove the temp sensor from the block and just let the fluid wash out? How do you know you got all of it?
I usually loosen the temp sensor enough to allow air/coolant to leak out. I do this with the engine running, so I do not remove the sensor.
There are several ways to bleed air from the cooling system. My favorite involves adding a tee to the top of the heater hose between the head and where the hose goes through the firewall. I went to Home Depot and got a tee, two hose barbs, a short nipple, and a cap/plug. All of these were in brass. I added these to the highest point of the heater hose between the head and the firewall as this is the highest point of the cooling system. The cooling system is filled, the cap/plug is removed, water is added to the tee, up to the top of the threads of the nipple, to completely replace any air found there.
I had some pictures of what I did posted in this section of the forum a few years ago, but my search abilities are not very good so I wasn't able to find them.
Don
I had some pictures of what I did posted in this section of the forum a few years ago, but my search abilities are not very good so I wasn't able to find them.
Don
X2, this is the best way to get a actual number/temperature.
GA Architect
SILVER Star
FWIW - After a 7 mile jog this morning, I've been driving all around for over an hour doing weekend stuff. While pulling into the hood, I remembered this thread. Here are my gauge readings for basically an OEM set up:
Just after I pulled into the garage.
Just after I pulled into the garage.
