Hey guys on my winter road trip a few hundred miles from home and my 3vze 4runner starts to boil coolant out the hose. I stopped every few miles to top off the radiator, the expansion tank was full, but the whole radiator was boiling and very low.The temp gauge sat at 2/3, but normally it hangs around 1/3 fully warmed up. I was getting strong heat the whole time out of the heater as well.

I recently changed the radiator fluid, i am using green (what was in it before), i intend to replace the radiator cap tomorrow as the system did not seem to be very pressurized.



I am looking for suggestions to help me make it home, Thanks guys. (if you cant tell im somewhat panicked)

 

It's probably the rad cap if the water is evaporating from the radiator and not sucking in cool water form the exp tank. Good luck man, sucks to be far from home.

Toyota red is better for Toyotas but flush the system 4 or 5 times to get all the green out first. With red you don't have to flush the system as much and it stays generally cleaner. Green contains minerals that help the longevity of American engines but the Japanese motors aren't designed the same way and green ends up having the adverse effect on Toyotas. But the red/green stuff wouldn't be related to your issue

 

my guess is it got low on coolant and overheated. that introduces air in the system. you can try to burp it hot, but best way is to top it off, top off the reservoir then let it cool.

in the morning check the coolant level under the cap, top off it and the reservoir and have a go at it.

if still not helping you can pull the thermostat for increased water circulation and to elimate possible failed thermostat.

once you've tackled air in the system, and replaced the cap. then the thermostat only thing left is the water pump an that is not an "on the road" project as its basicly a timming belt change to replace it.

 

Thanks for both replies, i after replacing the radiator cap i drove around 400 miles from Eureka to Portland without overheating. Thing was scary ill say that and i now carry a good amount of extra fluids at all times.

 

good to hear an easy fix for a change!!!!