first off thanks for your help on my idle last time!
My truck overheats in one condition-after a few minutes of highway driving. It is stable otherwise.
Here is what I have done to trouble shoot so far:
pressure test and check OEM radiator for stoppage/blockage
gut thermostat
burp system
all new fluids
stock timing
valve adj
new egr

fan clutch
water pump
oem radiator cap
hoses
no leaks
new 50/50
compression tested
There are no issues with the head gaskets
There is no knocking-it runs fine even when this hot
The 02 tested ok when cold on ohmeter

No exaust leaks between engine and 02 sensor
no trouble codes


Could it be a lean condition making it this hot?
Should I do the AFM mod or replace the 02 sensor?

Any help would be greatly appreciated

 

If the Ac condensor fan isnt working that could explain your problem. there is a resistor block that falls apart.

 

If you're overheating on the highway, I'd guess your radiator is clogged. Has it ever had stop leak or equivalent used in it?

 

It runs a bit cooler with the AC off and the heater on, but the needle is still very close to red & if I push it, coolant will boil out into overflow.

 

From what I've read,
a bad O2 would make it richer, not leaner
if it was caused by a lean condition, there would be knocking/detonation
so adj the afm probably won't help
Any ideas where to go next?

 

X2 check your radiator, probably clogged....

 

my 2 cents...

my 3vz was doing similar thing. I went through everything, replaced all but radiator. Radiator was flowing fine.

However, I took some advice and replaced the radiator. Not a problem since. I'm not the best mechanic but seemed when hot the flow stopped in the radiator.

 

I think I am going to have to try a radiator. If anyone knows of a high performance fan clutch or water pump, please let me know, thanks!

 

OEM stock fan clutch & water pump work fine under all conditions.

You may have flow in the radiator, but you're not getting ENOUGH at speed when you're generating a lot of heat. You have clogged passages. I almost guarantee someone has used stop-leak or equivalent in it at some point.

how many miles on the engine? Do you use Toyota RED coolant?

 

I'm running green 50/50-I hate to replace that nice OEM brass top radiator. Should I have it cleaned, clean it myself or just replace it? 130Kmiles

 

Do you have a good radiator shop nearby? They can check to see if there is a problem before you replace/rod it.

 

any updates...I have the same problem and looking into getting a new radiator too...thanks

 

FYI: https://www.yotatech.com/forums/f116...d-pics-193478/

 

I have a 22RE and not the 3.0, but I picked up a really nice all aluminum one from an online auction, $125 I think with shipping and not only did it look cool, but it has run very nice and installed like a breeze, I had minimal tweaking to get it in.