Overheating Issue FJ60 1986 (1 Viewer)

[Dr. John]

No one has mentioned the block drain valve just below the manifolds. I had it vibrate loose once and lose coolant.

 

[bwesty]

A simple and often overlooked issue is filling the radiator. Are you for certain that you completely filled the entire system with a sufficient quantity of coolant? It takes more effort to fill these than other vehicles sometimes. Get a radiator fill funnel to help, Lisle makes a good one.

 

[2mountainfish]

I installed a little in line temp gauge in the heater line. It’s from a motorcycle and i just gave it switched 12v power.

It put all my cooling system concerns at ease.

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Is this the style you used with the digital gauge? What mm did you use?

 

[Tbrad]

As others have said, pressure test should tell you what you need to know.

Have you checked the heater pipes routed behind the engine on the FW? There is a heat shield covering some parts of them up but so usually you can only see the ends of them with the motor in place. If coolant shows on the clutch slave, maybe coolant is leaking out the pipes and running down the pipe into the clutch slave? There are a ton of hoses right above that area that could be suspect. The little hose that connects the rear heater splitoff to the heater core maybe?:

View attachment 1885810
Or the heater pipe that runs behind the FW. Maybe its rusted out finally and is leaking where its not visible? Might need to run a mirror behind there to see whats going on:

View attachment 1885816

The heater valve on the FW too could just be leaking or cracked if its not been replaced.

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All that stuff is right above the clutch slave. The fact you are unable to see it with engine running sounds to me like its hidden somewhere.

Again a pressure test should reveal all this. Just some ideas of where to look. Anyways HTH.

I replaced the heater valve and the hoses but I haven’t checked the hoses behind the firewall. I will get a mirror and check some hidden areas like you recommended. Thanks!

 

[Tbrad]

A simple and often overlooked issue is filling the radiator. Are you for certain that you completely filled the entire system with a sufficient quantity of coolant? It takes more effort to fill these than other vehicles sometimes. Get a radiator fill funnel to help, Lisle makes a good one.

I put in a little over 4 gallons which according to the MM should be completely full right?

 

[Tbrad]

Just wanted to give you guys an update. I feel like an idiot but the solution was the best case scenario haha so I pressure tested it and I had about 6 clamps that were either placed on crooked/ not tightened down completely I then tightened the water pump belt and parked it up hill to burp the system for about an hour to make sure all of the air was out of the system. I plan on doing the compression test next weekend for peace of mind thank you for all of the help!

 

[bwesty]

Good to hear, glad you got it working better and sealed up.