Anyone know how to bleed air out of the cooling system (if there is any air)? Some cars have a bleeder valve at the highest point of the cooling system and turning on the heating at high and opening the valve usually bleeds it. Just wondering if there is anything similar on the IS250 or what the procedure is? I'm not sure if I have air or not in my system but occasionally on startup I hear water noise but disappears a few minutes later.

 

It is not air in the system per-say, but more than likely a bad water pump.

 

to bleed, just let the car run or raise the front end up. check for leaks and worst case senario, it could be a headgasket

 

Let the car running with heater on ( high temp) while the radiator cap is open. I let my car run about 5 minutes after i flushed coolant system.