1991 LC over heating when AC on ... PLEASE HELP!

[cietom]

You guys, i have a question, how many rows has the original radiator for the 3fe?. I have an aftermarket one with just 2.

Pretty sure I counted 2 rows on my original when I took it out, and my aftermarket was the same thickness.

You might want to try simply replacing the fan clutch with the new one before modifying it with higher viscosity oil. The green hub fan clutch is a different design internally with more fluid shearing surfaces than the blue hub found on the 1FZ-FE engines. In its new stock form it is pretty robust.

I'm not sure which fan clutch I have installed on mine, but I'm assuming it's the original 3FE clutch. It gets to be 115 here during the day and stays over 100 even at night during this time of year, do you think it's still best to leave the fluid as is? Either way, it's pretty simple to take it out so I guess wouldn't hurt to try it in its stock form first. Mine might just be really weak from age. Temps started creeping up again today in a drive thru getting coffee, had to turn the A/C off and throw the heat on max speed to get it to cool down.

 

[Raultlc]

Pretty sure I counted 2 rows on my original when I took it out, and my aftermarket was the same thickness.



I'm not sure which fan clutch I have installed on mine, but I'm assuming it's the original 3FE clutch. It gets to be 115 here during the day and stays over 100 even at night during this time of year, do you think it's still best to leave the fluid as is? Either way, it's pretty simple to take it out so I guess wouldn't hurt to try it in its stock form first. Mine might just be really weak from age. Temps started creeping up again today in a drive thru getting coffee, had to turn the A/C off and throw the heat on max speed to get it to cool down.

Probably i will buy a 3 row ebay radiator. I will let you know if i solve this with a bigger radiator.

 

[skhochay]

if the rig runs normally without AC being on then your problem with the fan and fan-related components
1. fan clutch is out
2. fan shroud is missing
3. fan is not pulling air and dispersion out evenly
4. fan sits too deep in the shroud it needs to be 80% out the shroud

Note:
1 row 2 row or 3-row radiator is not a solution as they are the same size just split

 

[cietom]

if the rig runs normally without AC being on then your problem with the fan and fan-related components
1. fan clutch is out
2. fan shroud is missing
3. fan is not pulling air and dispersion out evenly
4. fan sits too deep in the shroud it needs to be 80% out the shroud

Note:
1 row 2 row or 3-row radiator is not a solution as they are the same size just split

I agree, it takes a bit, but with the heater blower acting like a secondary fan, my rig slowly cools back down to normal. My fan shroud is in-tact and the fan definitely is sitting properly, so I'll check back in when my new fan clutch comes in. I'll try it stock first, and if it continues to overheat in the hot Arizona climate, I'll be bumping up the fluid in the fan clutch to the 15k CST I ordered. I can run it at idle in the parking lot during our hot days to test it, should have everything in this weekend. I'll be driving my other car until everything comes in.

 

[skhochay]

I agree, it takes a bit, but with the heater blower acting like a secondary fan, my rig slowly cools back down to normal. My fan shroud is in-tact and the fan definitely is sitting properly, so I'll check back in when my new fan clutch comes in. I'll try it stock first, and if it continues to overheat in the hot Arizona climate, I'll be bumping up the fluid in the fan clutch to the 15k CST I ordered. I can run it at idle in the parking lot during our hot days to test it, should have everything in this weekend. I'll be driving my other car until everything comes in.

ok when the fan is pushing air on the engine is it pressing evenly all over the fan?

 

[Raultlc]

Hi guys,

I had replaced the fan clutch, water pump (both aisin for 3fe) i had installed the fan shroud (brand new from UAE) and replaced the head gasket, and im stilling having problems with the ac when its on and the truck its on traffic. Plus, the truck its running without the thermostat. Could this be the culprit of that? And also, i have a 2 rows radiator. How many rows has the original radiator for the 3fe?.

 

[cietom]

Ended up finding my issue to be the previous owner had a really dumbed down fan clutch installed, and not the beefy OEM unit.

Replaced it with a factory Aisin clutch as recommended by @jonheld and so far no overheating in 115 degree Phoenix weather! Still have the 15k oil just in case the fan needs more oomph, but don't think I'll need it, A/C stays cool at idle as well!

Picture of the comparison of the 2 clutches, new OEM on the left, what was in the truck on the right, yikes.