4runner92

I drive my 4runner daily with no problems but once a week I drive it about 15 miles on the freeway and when I get there it's always boiling in the overflow and the radiator. New thermostat and new waterpump last month and the gauge isn't reading hot any idea what's wrong?

mr toytech

sounds like an air pocket in the cooling system. or needs a new radiator cap.

yoterr

yeah, the only way to get air out of the system is to park the truck with the front end elevated and to start it with the rad cap off and let it warm up to operating temp and add water once it gets done bubbling...

TNRabbit

Could be air, but sounds more like clogged radiator.

baseballchamp157

if it aint clogged. and you do as yoterr says and that dont help. i believe you got yourself an exhaust to coolant leak. cause thats what i had in my 3.0 and it kept over heating.

sb5walker

"Boiling" in the overflow sounds like air being forced out of the top of the rad, and that could be exhaust gas going through a leaky head gasket. Recommend compression test, and leakdown test if necessary. Watch #s 6 & 1.