Ok so for over a year now my truck my truck has been losing coolant. I have to top it off every month. I believe I lose the coolant because it boils over in my radiator and spits out the over flow hose. The temperature never overheats it will just climb when I'm driving slow and not revving the engine. Every time in the morning when I start it up and press the gas I hear a rush of water through the climate control. Periodically when I 'm driving I will hear the same rush of water. According to my friend who is really good with Toyota's its a clogged radiator. I have replaced the radiator cap, and the thermostat also. No white smoke, no water in the oil.

 

No one knows??

 

did you try flushing out the system with a hose?

 

What you describe could be a air pocket in the cooling system. Don't know which engine you have but some are difficult to purge when you drain and refill the coolant. Might try draining coolant, raise the front of your truck as high as you can, then slowly add coolant. Make sure heater valve is open when you drain and refill so coolant gets into heater core.

 

check the radiator for cracks.check the hoses for cracks/holes. Mine (22re) has been losing coolant at the rate of me having to fill it up every 4-5 days, but I know why and where my radiator cracked. I'm just too lazy to get a new one. I tried fixing it with JB Weld...but It keeps busting through. I did find another leak in my rad though. I cant see how if the radiator was clogged..It would make you lose coolant. Is there something I'm missing? And yes, try flushing the coolant system.

 

I have flushed out the radiator and I have purged the cooling system. I've heard of people getting these symptoms when their radiators went out on them.

 

also may be a fan clutch issue since it starts creeping temps at low vehicle / engine speed