I'm at my Wits End! 3fe getting hot.. (1 Viewer)

[Desertruck]

Hey everyone I'm a long time lurker first time poster. I need help. This is gonna be a long post...
92 3FE
So I've been fighting a getting too warm but not necessarily overheating issue. In summer NorCal 100ish degrees truck will get up to about 210°. If I turn on the AC (converted to r134) I get up to about 225° in my opinion this is way too hot for continued use. If I turn the AC off the temp drops very slowly back to about 210. If I turn the heater on full blast I can get temp quickly down to 200. When I cruise at 65 mph temp slowly climbs if I downshift to 3rd my temp drops a little. It almost seems like the fan or water pump isn't spinning fast enough when I'm cruising.
Truck has 295,000 miles.
Head was fully rebuilt/machined and obviously new HG about 8k miles ago
Radiator and water pump replaced 10k ago and radiator flows water easily at high volume/no pressure (shoved garden hose in rad on full blast and the water drained out of the bottom faster than it could fill
Thermostat replaced 200 miles ago
Fan clutch replaced (aisin green hub) 20 miles ago
All hoses were replaced around the time the radiator was replaced and a aftermarket analog temp guage was installed in the upper radiator hose close to thermostat housing.
I don't lose any coolant or have any excess pressure pushing into the reservoir. I have read every overheating 3fe thread on this site at least 3 or 4 times and I've replaced everything except the ridiculously overpriced oil cooler.. I've flushed multiple times and have new Toyota red. Please help me I'm a very decent shadetree mechanic and have talked to multiple people about my problem and now I'm looking for some LC 3fe specific advice.
I'm planning on double checking and adjusting my distributor timing. I know if it's retarded at all you get some serious heat happening . Please hit me with anything you've got.

 

[Marco Lau]

need to know what kind of radiator did you replace with?
based on info. provided above, i would suspect it is your radiator or fan clutch. I would try changing the clutch oil to a thicker oil, like 15k or 20k and see if your temp. drops would be the most logical way before you start going down the rabbit hole. My rig with an aftermarket alum. radiator, modified Green hub with thicker oil and a healthy cooling system can idle all day with AC on and the rig sits @ 190-195F till it runs out of gas....210 - 215 is unacceptable IMO with AC on blast and highway, all points to an insufficient radiator. (my old CSF radiator would hover around 210-215F on highway manners and forget about AC, you have no margin of error.) I would expect those kind of temp if i am pulling a trailer w/ AC on full blast....190F highway w/ AC off, 195 w/ AC on blast, 200-205F pulling grade. Anything past 215 is not normal and something is off....

 

[Desertruck]

need to know what kind of radiator did you replace with?
based on info. provided above, i would suspect it is your radiator or fan clutch. I would try changing the clutch oil to a thicker oil, like 15k or 20k and see if your temp. drops would be the most logical way before you start going down the rabbit hole. My rig with an aftermarket alum. radiator, modified Green hub with thicker oil and a healthy cooling system can idle all day with AC on and the rig sits @ 190-195F till it runs out of gas....210 - 215 is unacceptable IMO with AC on blast and highway, all points to an insufficient radiator. (my old CSF radiator would hover around 210-215F on highway manners and forget about AC, you have no margin of error.) I would expect those kind of temp if i am pulling a trailer w/ AC on full blast....190F highway w/ AC off, 195 w/ AC on blast, 200-205F pulling grade. Anything past 215 is not normal and something is off....

My radiator was a generic replacement from rockauto. Looking at getting an aluminum 3 core one as a replacement. I just did the clutch last night with the green hub and it is a slight improvement over my old one... By slight I mean 2 to 3 degrees cooler, but not enough.

 

[Marco Lau]

Try adding thicker oil to the green hub and see if your temp improves? Which Rockauto radiator? I see they have a Liland Unit in stock. I would go with their 2 core alum unit. I am currently running the Liland unit, it is much cheaper than Ron Davis, and i have both and the Liland cools just as good as a $1400 unit. Avoid cooper/brass radiator. They are not adequate to cool these rigs loaded up with stuff

 

[Desertruck]

Try adding thicker oil to the green hub and see if your temp improves? Which Rockauto radiator? I see they have a Liland Unit in stock. I would go with their 2 core alum unit. I am currently running the Liland unit, it is much cheaper than Ron Davis, and i have both and the Liland cools just as good as a $1400 unit. Avoid cooper/brass radiator. They are not adequate to cool these rigs loaded up with stuff

This is the one I got.. what oil weight do you suggest for the clutch

 

[Desertruck]

Try adding thicker oil to the green hub and see if your temp improves? Which Rockauto radiator? I see they have a Liland Unit in stock. I would go with their 2 core alum unit. I am currently running the Liland unit, it is much cheaper than Ron Davis, and i have both and the Liland cools just as good as a $1400 unit. Avoid cooper/brass radiator. They are not adequate to cool these rigs loaded up with stuff

For the small bump in price why not the 3 core?

 

[Marco Lau]

For the small bump in price why not the 3 core?

I believe 2 core alum. is more efficient than 3 core. My Ron Davis is a 2 core design, so is my Liland.

 

[Marco Lau]

i start with adding 15k in there for starter...

 

[leonard_nemoy]

My radiator was a generic replacement from rockauto.

Try a different radiator. You could also try running 40% coolant to 60% water mix. Pretty common in warmer climates. You would still be good down to -10F.....

 

[Desertruck]

Try a different radiator. You could also try running 40% coolant to 60% water mix. Pretty common in warmer climates. You would still be good down to -10F.....

I'm running about this... I didn't measure it exactly though

 

[mudgudgeon]

Maybe a silly question.
How are you measuring engine / coolant temps?
Have you verified you're getting a true reading?
Not relying on a faulty sensor reading?

If you're not boiling coolant at those temps, seems to me like your cooling system is in good shape.

Maybe you've overlooked something simple.

 

[Malleus]

I just went through this with one of my 80s, although with the 1FZ-FE engine. I had both a stock radiator and an aftermarket brass/copper CSF flow tested, and both tested the same. After replacing every cooling system component, including a thermostat which wasn't opening fully, I believe the difference was the radiator. FWIW. replacing the clutch did absolutely nothing for me.

With the rodded aand rebrazed CSF, it went from running 210°F+to a reasonable 190-195°F. It still doesn't run as cool as my other 80, but I also believe I have a transmission heating problem, which you probably don't have.

 

[76FJ40]

Do you still have the fan shroud installed?

 

[LAMBCRUSHER]

I had to re-oil and re-tune an aqua hub fan clutch to get it to keep enough friction to turn the fan at highway speeds. Of course, verify your radiator is flowing enough- as you said you have. If you have flow, you have a sealed system, then it's either an excess of heat generation (mechanical badness) or a lac of air flow over the radiator. Another factor could be an thing inhibiting airflow, such as buggs clogging the ac/ condenser. After I took care of all the usual suspects, my issue was the stock tuned fan clutch just didn't have the balls to function in a high heat environment. The opening and fully locked-on temperature for the fan clutch can be adjusted to open and lock-on sooner, and thicker csk oil can be added to prevent sheering and slippage. HTH

 

[peacesells63]

Check your timing and set it per the FSM before you replace anything. Older toyota motors run hot with too much advance, temps climbing at highway speeds is a trademark of too much timing.

 

[nOtArEaLcRuIsEr]

What temp thermostat did you put in it?

What do you think your weight is compared to the sticker GVW?

 

[Desertruck]

Maybe a silly question.
How are you measuring engine / coolant temps?
Have you verified you're getting a true reading?
Not relying on a faulty sensor reading?

If you're not boiling coolant at those temps, seems to me like your cooling system is in good shape.

Maybe you've overlooked something simple.

So I've considered this... I'm using an analog (capillary tube) eqqus guage, it's about the cheapest one you can get. I've thought that maybe it's way off but when the aftermarket guage reads 220 my stock dash guage starts to climb slightly so I'm thinking it's not too far off, however I have no way to check or verify it's accuracy

 

[Desertruck]

Maybe a silly question.
How are you measuring engine / coolant temps?
Have you verified you're getting a true reading?
Not relying on a faulty sensor reading?

If you're not boiling coolant at those temps, seems to me like your cooling system is in good shape.

Maybe you've overlooked something simple.

So I've considered this... I'm using an analog (capillary tube) eqqus guage, it's about the cheapest one you can get. I've thought that maybe it's way off but when the aftermarket guage reads 220 my stock dash guage starts to climb slightly so I'm thinking it's not too far off, however I have no way to check or verify

Check your timing and set it per the FSM before you replace anything. Older toyota motors run hot with too much advance, temps climbing at highway speeds is a trademark of too much timing.

Re did the dist timing last night I did have it advanced because 3fe's are slow I'm now spot on how the book says to set it

 

[Desertruck]

Do you still have the fan shroud installed?

Yes fan shroud is installed

 

[Desertruck]

What temp thermostat did you put in it?

What do you think your weight is compared to the sticker GVW?

Thermostat is 180° it's all the local auto parts had. And my weight is about 6200 lbs