Tacoma Overheating Problems

Hello all, long story short my 2008 Tacoma 4x4 is having overheating problems. The temp gauge inside the Tacoma never really moves but the coolant inside the expansion tank (area where you fill up coolant) boils up and starts to spray out of the cap. I can tell it gets hot because I can smell coolant through my vents when I am on the road, usually pull over immediately and let it cool down and top off any lost coolant due to it boiling out. I have replaced the thermostat and completely cleaned radiator and flushed it. No leaks observed in radiator. Water pump is good. After themostat was replaced it seemed like the problem was temporarily fixed, now it’s doing it again. Usually happens on the freeway or going up hills. Any suggestions would help immensely.

 

Test/replace your rad cap

 

Is your radiator cap good? They are bad about the little plastic check valve falling off, when that happens they wint hold pressure.

 

I have not tested the radiator cap, could be a simple fix thank you. I will replace that and see what she does.

 

If radiator cap doesn't fix the issue, check for a head gasket leak. While the engine is cold, open the radiator cap and rev the engine a little. Watch for air bubbles coming out.

 

If there are places that rent tools near by, then I would rent a cooling system pressure tester and test the cap and also the cooling system while you have it so you don't end up spending money you don't have to. If it is a cap i'd recommend an oem cap.

 

If everything else checks out then check your fan clutch. Spin it by hand with engine off. It should stop almost immediately.

 

Fan engaging? -> pressure test for faulty Rad cap -> test thermostat for sticking (which you already did). Then move onto bigger issues (head gasket, etc.)
First 3 cheap to replace or free to test.
Can the thermostat be put in backwards?

 

My truck is smelling like it’s running hotter than it should so, I’m going to looking into the tests in this thread to hopefully get some answers.