Stop me from putting a bullet in this F'n 60

[hodag]

87' FJ60, still overheating, Im not losing any fluid.

Radiator has been rodded and cleaned, and new cans put on it.

Ive burped it and put a new rad cap on it.

Checked (and replaced) the belts and adjusted tension.

Blew out the condenser and radiator with water and air.

The two things I havent done are replace the fan clutch (but by the sounds of it, I dont think mine is bad) and replace the thermostat.

One thing I did notice however is that my fan sits half in and half out of the shroud. The shaft on the fan clutch seems approx 1 1/2" shorter than the new one still in the box. Could the fan not being close enough to the rad be my problem? My buddy said the fan on his 60 is completely inside the shroud.

Im at my wits end and I'm tired of running the heater in 95 degree temps. Thanks for any help, Hodag

 

[Dirty Toad]

i would replace the thermostat.

feel around the hoses, if the one over the top of the t-stat is not hot (when you have your hand a few inches down the pipe from the t-stat) then that is the likely item causing your pain. easy fix too.

just my .02

 

[hj60]

The fan should be at least 75% within the shroud. 90% is normal.
CHANGE YOUR THERMOSTAT! It's the first thing you should have done. It's cheap and easy to do.

Now, are you sure it's overheating?
Does the needle move down when you run the heater? If it does, then it's prolly a cooling issue. If not, it may be a gauge issue.

 

[Fearnofish!]

Change that thermo then you only have one choice... water pump. If you go that far might as well think of it as a good time to replace anything else up front. BTW I went through 3 thermos before I got one that was right on temp. Get one of those digital infrared thermometers to shoot at hoses and the radiator as well as the thermostat housing.

 

[euclid]

Go ahead and put a bullet in it. Take pictures. Post them.

 

[krzyabncanuck]

Number 1 buy a handheld digital infared thermometers and check all of your hoses, and radiater.You still might have some blockage somewhere in your rad. I though mine was running high last summer and got one of those digital things and found out it was only running 185-190. Don't just throw your money away changing parts, figure out whats wrong then just change that part.

 

[Slow N Steady]

The TWO best investments you'll ever make are a Mechanical Temperature Guage and a Vacuum Guage! Spend the coin and put them in - permanately! I bought some guage pods and mounted them on the drivers A-Pillar. It's amazing how much piece of mind these two give. You will probably find your stock guage is off a bit. Good luck.

 

[cwb]

Are you SURE the fan clutch isn't bad? It can feel like it has a little resistance and still be bad. When the engine is hot, the fan should have a lot of resistance. If the thermostat is bad, the BOTTOM hose will be cold when the engine is hot.

 

[wingysataday]

When my fan clutch went out I could drive around all day and come home, open the hood, keep the truck running, and stop my fan with my fingers and spint it the opposite way. That's how I knew mine was bad. just my .05cents

 

[djanis99]

if the fan clutch is bad it won't overheat on highway. The fan clutch keeps air going by the radiator when there is none otherwise ie stop and go traffic. If it is the thermostat, it will overheat all of the time. If the gauges are bad which mine are, the temp will spike fast to the top it does this simultaneously with the fuel gauge. If your engine apears to be overheating and the gas gauge is spiked sky high, it is your gauges.

 

[vtcruiser60]

I have chased similar gremlins, but not knowing much about what you have done besides the radiator work makes this a bit more difficult. As the others have said, check that thermostat first. Might want to replace it if it doesn't pop open in hot water. Make sure the rubber gasket that goes with the t-stat is not reversed. Ok...other things to make it run hot, from simple to complex:

1. Insufficient coolant in radiator.
2. Air bubble in cooling system. Time to burp.
3. Faulty temperature sending unit. Ground it out and see if the temperature gauge spikes. If this is faulty you might be chasing a gremlin...meaning your temp might be totally normal, but the temp gauge is getting bad info from the sending unit. Aftermarket sending units are $10...OEM is like $22.
4. Choke poorly adjusted, running hot. Make sure the butterfly in the carb is closed as per the FSM. This will make it run hot.
5. Running too rich. Adjust air/fuel mixture.

6. More complex and problematic:
A. Incorrect timing
B. Valve clearances poorly adjusted
C. CRACKED Head. You could lose coolant internally....very slowly and be burning it off. Any puffs of white smoke?
D. CFaulty EGR...
E. Or...Cracked block....yes, I speak from experience.

HTH

 

[FJ40Jim]

You're just baiting me with this, aren't you?

Ok...other things to make it run hot, from simple to complex:
1. Insufficient coolant in radiator.
2. Air bubble in cooling system. Time to burp.
3. Faulty temperature sending unit.
4. Choke poorly adjusted, running hot. Make sure the butterfly in the carb is closed as per the FSM. This will make it run hot.

The choke butterfly should be OPEN when the knob is pushed in. Choke knob pulled out, choke butterfly should be fully closed.

If the choke is misadjusted and partially closed during normal operation, the temperature will be reduced due to: 1. rich mixture burns cooler than ideal, 2. restricted airflow makes engine run weak, limiting total power (heat) availability.

5. Running too rich. Adjust air/fuel mixture.

See above. FWIW, peak combustion temps occur a little lean of ideal mixture. Very lean combustion will put more heat into cooling jacket because aggresive flame front will burn insulating boundary layer fuel & oil off metal surfaces and attempt to burn the metal.

6. More complex and problematic:
A. Incorrect timing

Specifically, retarded ignition timing. This is most important under load, so be sure the ignition advances are providing the right timing when operating at normal speed.

B. Valve clearances poorly adjusted

This is an important tuneup item on these engines, but has no effect on overheating the coolant.

C. CRACKED Head. You could lose coolant internally....very slowly and be burning it off. Any puffs of white smoke?
E. Or...Cracked block....yes, I speak from experience.
D. Faulty EGR...

The EGR system does increase engine temps by making the engine work harder to produce a given amount of power. This is normal. If the EGR system is defective and inop, then the engine will run better/cooler. If there is too much EGR, then engine will run very bad, so overheating will be a secondary concern, after surging, stumbling, lack of power....

And finally, every FJ60 to date that has had persistent overheating problems has been cured by a new OEM radiator, after all the usual suspects (T-stat, WP, fanclutch) were tried. That included the one w/ the custom built monster radiator and the one w/ the new OEM radiator that turned out to be full of Stop-leak & RTV chunks.

Okay, I'm done now.