2004 V6 4X4 ....HOW TO BLEED/REMOVE AIR BUBBLES FROM COOLING SYSTEM??????

Hello everyone,

I have a 2004 Tacoma V6 3.4L 4x4 that has been giving me some random overheating problems, which basically have only happened while idling. After changing the t-stat and fan clutch, and confirming that revving at 1500RPM with the heater on DOES lower the temperature back to normal operating point, I believe, and HOPE that the only thing left to do is bleed out any air bubbles trapped in the system.

I had a few suggestions to open up the radiator cap, turn the truck on, and when the coolant level drops, re-fill it. But everytime I've tried that, the coolant level almost immediately begins to overflow very slowly.

Should I wait a few minutes and let it overflow?? Is this the normal way to do it? Is it supposed to overflow until the t-stat kicks in and then the coolant will drop???

 

Sure you don't have a head gasket problem, I changed my coolant drained the block and didn't have a air bubble issue.

 

I had a heater core issue and resolved it by flushing my heater core and then bleeding the air out of the radiator. This was my final update post:



Success!!!!!

I flushed the heater core at lunch. I ran water through a garden hose through both lines about 4 times each till the water ran clear. Really wasn't to much discoloration. I then took off the radiator cap and put a funnel half filled with fluid in the radiator top and ran the engine for 20-30 minutes to get any trapped air out. As the fluid dropped I would add more to the funnel to keep it half filled. Once I stopped having bubble burps for 5 minutes or so, I removed the funnel and topped off the radiator.

I turned it off and let it sit till the engine was cold then started it up and switched on the heater to warm the cab like on a cold morning. I went in the house for a sandwich and came back 10 minutes later and was met with nice warm air flowing through the vents. I am now ready for winter!

Thank you all for your help! This forum is always a great resource for me and helps me avoid going to the dealership or local mechanic.

Good Luck!

 

Hi everyone,

Thanks for the input. I just now fixed the problem..FINALLY!!!

So aparently, the lower radiator hose was very old and weak, and it had been collapsing due to the suction pressure from the water pump. I changed it out and it's now running great. Not a single sign of overheating. In fact, the needle seems to be even lower than the middle now!!